certusone
/
tendermint
mirror of https://github.com/certusone/tendermint.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

docs: convert markdown to rst

This commit is contained in:
Zach Ramsay 2017-08-30 17:54:25 -04:00
parent e19fa59b63
commit 70c0f4b936
16 changed files with 1515 additions and 1150 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

257
docs/abci-cli.rst Normal file
View File

@ -0,0 +1,257 @@
Using the abci-cli
==================
To facilitate testing and debugging of ABCI servers and simple apps, we
built a CLI, the ``abci-cli``, for sending ABCI messages from the
command line.
Install
-------
Make sure you `have Go installed <https://golang.org/doc/install>`__ and
`put ``$GOPATH/bin`` in your
``$PATH`` <https://github.com/tendermint/tendermint/wiki/Setting-GOPATH>`__.
Next, install the ``abci-cli`` tool and example applications:
::
go get -u github.com/tendermint/abci/cmd/...
If this fails, you may need to use ``glide`` to get vendored
dependencies:
::
go get github.com/Masterminds/glide
cd $GOPATH/src/github.com/tendermint/abci
glide install
go install ./cmd/...
Now run ``abci-cli --help`` to see the list of commands:
::
COMMANDS:
batch Run a batch of ABCI commands against an application
console Start an interactive console for multiple commands
echo Have the application echo a message
info Get some info about the application
set_option Set an option on the application
deliver_tx Append a new tx to application
check_tx Validate a tx
commit Get application Merkle root hash
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--address "tcp://127.0.0.1:46658" address of application socket
--help, -h show help
--version, -v print the version
First Example - Dummy
---------------------
The ``abci-cli`` tool lets us send ABCI messages to our application, to
help build and debug them.
The most important messages are ``deliver_tx``, ``check_tx``, and
``commit``, but there are others for convenience, configuration, and
information purposes.
Let's start a dummy application, which was installed at the same time as
``abci-cli`` above. The dummy just stores transactions in a merkle tree:
::
dummy
In another terminal, run
::
abci-cli echo hello
abci-cli info
The application should echo ``hello`` and give you some information
about itself.
An ABCI application must provide two things:
- a socket server
- a handler for ABCI messages
When we run the ``abci-cli`` tool we open a new connection to the
application's socket server, send the given ABCI message, and wait for a
response.
The server may be generic for a particular language, and we provide a
`reference implementation in
Golang <https://github.com/tendermint/abci/tree/master/server>`__. See
the `list of other ABCI
implementations <https://tendermint.com/ecosystem>`__ for servers in
other languages.
The handler is specific to the application, and may be arbitrary, so
long as it is deterministic and conforms to the ABCI interface
specification.
So when we run ``abci-cli info``, we open a new connection to the ABCI
server, which calls the ``Info()`` method on the application, which
tells us the number of transactions in our Merkle tree.
Now, since every command opens a new connection, we provide the
``abci-cli console`` and ``abci-cli batch`` commands, to allow multiple
ABCI messages to be sent over a single connection.
Running ``abci-cli console`` should drop you in an interactive console
for speaking ABCI messages to your application.
Try running these commands:
::
> echo hello
-> data: hello
> info
-> data: {"size":0}
> commit
-> data: 0x
> deliver_tx "abc"
-> code: OK
> info
-> data: {"size":1}
> commit
-> data: 0x750502FC7E84BBD788ED589624F06CFA871845D1
> query "abc"
-> code: OK
-> data: {"index":0,"value":"abc","exists":true}
> deliver_tx "def=xyz"
-> code: OK
> commit
-> data: 0x76393B8A182E450286B0694C629ECB51B286EFD5
> query "def"
-> code: OK
-> data: {"index":1,"value":"xyz","exists":true}
Note that if we do ``deliver_tx "abc"`` it will store ``(abc, abc)``,
but if we do ``deliver_tx "abc=efg"`` it will store ``(abc, efg)``.
Similarly, you could put the commands in a file and run
``abci-cli --verbose batch < myfile``.
Another Example - Counter
-------------------------
Now that we've got the hang of it, let's try another application, the
"counter" app.
The counter app doesn't use a Merkle tree, it just counts how many times
we've sent a transaction, asked for a hash, or committed the state. The
result of ``commit`` is just the number of transactions sent.
This application has two modes: ``serial=off`` and ``serial=on``.
When ``serial=on``, transactions must be a big-endian encoded
incrementing integer, starting at 0.
If ``serial=off``, there are no restrictions on transactions.
We can toggle the value of ``serial`` using the ``set_option`` ABCI
message.
When ``serial=on``, some transactions are invalid. In a live blockchain,
transactions collect in memory before they are committed into blocks. To
avoid wasting resources on invalid transactions, ABCI provides the
``check_tx`` message, which application developers can use to accept or
reject transactions, before they are stored in memory or gossipped to
other peers.
In this instance of the counter app, ``check_tx`` only allows
transactions whose integer is greater than the last committed one.
Let's kill the console and the dummy application, and start the counter
app:
::
counter
In another window, start the ``abci-cli console``:
::
> set_option serial on
-> data: serial=on
> check_tx 0x00
-> code: OK
> check_tx 0xff
-> code: OK
> deliver_tx 0x00
-> code: OK
> check_tx 0x00
-> code: BadNonce
-> log: Invalid nonce. Expected >= 1, got 0
> deliver_tx 0x01
-> code: OK
> deliver_tx 0x04
-> code: BadNonce
-> log: Invalid nonce. Expected 2, got 4
> info
-> data: {"hashes":0,"txs":2}
This is a very simple application, but between ``counter`` and
``dummy``, its easy to see how you can build out arbitrary application
states on top of the ABCI. `Hyperledger's
Burrow <https://github.com/hyperledger/burrow>`__ also runs atop ABCI,
bringing with it Ethereum-like accounts, the Ethereum virtual-machine,
Monax's permissioning scheme, and native contracts extensions.
But the ultimate flexibility comes from being able to write the
application easily in any language.
We have implemented the counter in a number of languages (see the
example directory).
To run the Node JS version, ``cd`` to ``example/js`` and run
::
node app.js
(you'll have to kill the other counter application process). In another
window, run the console and those previous ABCI commands. You should get
the same results as for the Go version.
Want to write the counter app in your favorite language?! We'd be happy
to add you to our `ecosystem <https://tendermint.com/ecosystem>`__!
We're also offering `bounties <https://tendermint.com/bounties>`__ for
implementations in new languages!
Notes
-----
The ``abci-cli`` is designed strictly for testing and debugging. In a
real deployment, the role of sending messages is taken by Tendermint,
which connects to the app using three separate connections, each with
its own pattern of messages.
For more information, see the `application developers
guide </docs/guides/app-development>`__. For examples of running an ABCI
app with Tendermint, see the `introductory
guide </docs/getting-started/first-abci-app>`__.

128
docs/app-architecture.rst Normal file
View File

@ -0,0 +1,128 @@
Application Architecture Guide
==============================
Overview
--------
A blockchain application is more than the consensus engine and the
transaction logic (eg. smart contracts, business logic) as implemented
in the ABCI app. There are also (mobile, web, desktop) clients that will
need to connect and make use of the app. We will assume for now that you
have a well designed transactions and database model, but maybe this
will be the topic of another article. This article is more interested in
various ways of setting up the "plumbing" and connecting these pieces,
and demonstrating some evolving best practices.
Security
--------
A very important aspect when constructing a blockchain is security. The
consensus model can be DoSed (no consensus possible) by corrupting 1/3
of the validators and exploited (writing arbitrary blocks) by corrupting
2/3 of the validators. So, while the security is not that of the
"weakest link", you should take care that the "average link" is
sufficiently hardened.
One big attack surface on the validators is the communication between
the ABCI app and the tendermint core. This should be highly protected.
Ideally, the app and the core are running on the same machine, so no
external agent can target the communication channel. You can use unix
sockets (with permissions preventing access from other users), or even
compile the two apps into one binary if the ABCI app is also writen in
go. If you are unable to do that due to language support, then the ABCI
app should bind a TCP connection to localhost (127.0.0.1), which is less
efficient and secure, but still not reachable from outside. If you must
run the ABCI app and tendermint core on separate machines, make sure you
have a secure communication channel (ssh tunnel?)
Now assuming, you have linked together your app and the core securely,
you must also make sure no one can get on the machine it is hosted on.
At this point it is basic network security. Run on a secure operating
system (SELinux?). Limit who has access to the machine (user accounts,
but also where the physical machine is hosted). Turn off all services
except for ssh, which should only be accessible by some well-guarded
public/private key pairs (no password). And maybe even firewall off
access to the ports used by the validators, so only known validators can
connect.
There was also a suggestion on slack from @jhon about compiling
everything together with a unikernel for more security, such as
`Mirage <https://mirage.io>`__ or
`UNIK <https://github.com/emc-advanced-dev/unik>`__.
Connecting your client to the blockchain
----------------------------------------
Tendermint Core RPC
~~~~~~~~~~~~~~~~~~~
The concept is that the ABCI app is completely hidden from the outside
world and only communicated through a tested and secured `interface
exposed by the tendermint core </docs/specs/rpc>`__. This interface
exposes a lot of data on the block header and consensus process, which
is quite useful for externally verifying the system. It also includes
3(!) methods to broadcast a transaction (propose it for the blockchain,
and possibly await a response). And one method to query app-specific
data from the ABCI application.
Pros: \* Server code already written \* Access to block headers to
validate merkle proofs (nice for light clients) \* Basic read/write
functionality is supported
Cons: \* Limited interface to app. All queries must be serialized into
[]byte (less expressive than JSON over HTTP) and there is no way to push
data from ABCI app to the client (eg. notify me if account X receives a
transaction)
Custom ABCI server
~~~~~~~~~~~~~~~~~~
This was proposed by @wolfposd on slack and demonstrated by
`TMChat <https://github.com/wolfposd/TMChat>`__, a sample app. The
concept is to write a custom server for your app (with typical REST
API/websockets/etc for easy use by a mobile app). This custom server is
in the same binary as the ABCI app and data store, so can easily react
to complex events there that involve understanding the data format (send
a message if my balance drops below 500). All "writes" sent to this
server are proxied via websocket/JSON-RPC to tendermint core. When they
come back as deliver\_tx over ABCI, they will be written to the data
store. For "reads", we can do any queries we wish that are supported by
our architecture, using any web technology that is useful. The general
architecture is shown in the following diagram:
Pros: \* Separates application logic from blockchain logic \* Allows
much richer, more flexible client-facing API \* Allows pub-sub, watching
certain fields, etc.
Cons: \* Access to ABCI app can be dangerous (be VERY careful not to
write unless it comes from the validator node) \* No direct access to
the blockchain headers to verify tx \* You must write your own API (but
maybe that's a pro...)
Hybrid solutions
~~~~~~~~~~~~~~~~
Likely the least secure but most versatile. The client can access both
the tendermint node for all blockchain info, as well as a custom app
server, for complex queries and pub-sub on the abci app.
Pros: \* All from both above solutions
Cons: \* Even more complexity \* Even more attack vectors (less
security)
Scalability
-----------
Read replica using non-validating nodes? They could forward transactions
to the validators (fewer connections, more security), and locally allow
all queries in any of the above configurations. Thus, while
transaction-processing speed is limited by the speed of the abci app and
the number of validators, one should be able to scale our read
performance to quite an extent (until the replication process drains too
many resources from the validator nodes).
Example Code
------------
- `TMChat <https://github.com/wolfposd/TMChat>`__

299
docs/app-development.rst Normal file
View File

@ -0,0 +1,299 @@
Application Development Guide
=============================
ABCI Design
-----------
The purpose of ABCI is to provide a clean interface between state
transition machines on one computer and the mechanics of their
replication across multiple computers. The former we call 'application
logic' and the latter the 'consensus engine'. Application logic
validates transactions and optionally executes transactions against some
persistent state. A consensus engine ensures all transactions are
replicated in the same order on every machine. We call each machine in a
consensus engine a 'validator', and each validator runs the same
transactions through the same application logic. In particular, we are
interested in blockchain-style consensus engines, where transactions are
committed in hash-linked blocks.
The ABCI design has a few distinct components:
- message protocol
- pairs of request and response messages
- consensus makes requests, application responds
- defined using protobuf
- server/client
- consensus engine runs the client
- application runs the server
- two implementations:
- async raw bytes
- grpc
- blockchain protocol
- abci is connection oriented
- Tendermint Core maintains three connections:
- `mempool connection <#mempool-connection>`__: for checking if
transactions should be relayed before they are committed; only
uses ``CheckTx``
- `consensus connection <#consensus-connection>`__: for executing
transactions that have been committed. Message sequence is -
for every block -
``BeginBlock, [DeliverTx, ...], EndBlock, Commit``
- `query connection <#query-connection>`__: for querying the
application state; only uses Query and Info
The mempool and consensus logic act as clients, and each maintains an
open ABCI connection with the application, which hosts an ABCI server.
Shown are the request and response types sent on each connection.
Message Protocol
----------------
The message protocol consists of pairs of requests and responses. Some
messages have no fields, while others may include byte-arrays, strings,
or integers. See the ``message Request`` and ``message Response``
definitions in `the protobuf definition
file <https://github.com/tendermint/abci/blob/master/types/types.proto>`__,
and the `protobuf
documentation <https://developers.google.com/protocol-buffers/docs/overview>`__
for more details.
For each request, a server should respond with the corresponding
response, where order of requests is preserved in the order of
responses.
Server
------
To use ABCI in your programming language of choice, there must be a ABCI
server in that language. Tendermint supports two kinds of implementation
of the server:
- Asynchronous, raw socket server (Tendermint Socket Protocol, also
known as TSP or Teaspoon)
- GRPC
Both can be tested using the ``abci-cli`` by setting the ``--abci`` flag
appropriately (ie. to ``socket`` or ``grpc``).
See examples, in various stages of maintenance, in
`Go <https://github.com/tendermint/abci/tree/master/server>`__,
`JavaScript <https://github.com/tendermint/js-abci>`__,
`Python <https://github.com/tendermint/abci/tree/master/example/python3/abci>`__,
`C++ <https://github.com/mdyring/cpp-tmsp>`__, and
`Java <https://github.com/jTendermint/jabci>`__.
GRPC
~~~~
If GRPC is available in your language, this is the easiest approach,
though it will have significant performance overhead.
To get started with GRPC, copy in the `protobuf
file <https://github.com/tendermint/abci/blob/master/types/types.proto>`__
and compile it using the GRPC plugin for your language. For instance,
for golang, the command is
``protoc --go_out=plugins=grpc:. types.proto``. See the `grpc
documentation for more details <http://www.grpc.io/docs/>`__. ``protoc``
will autogenerate all the necessary code for ABCI client and server in
your language, including whatever interface your application must
satisfy to be used by the ABCI server for handling requests.
TSP
~~~
If GRPC is not available in your language, or you require higher
performance, or otherwise enjoy programming, you may implement your own
ABCI server using the Tendermint Socket Protocol, known affectionaltely
as Teaspoon. The first step is still to auto-generate the relevant data
types and codec in your language using ``protoc``. Messages coming over
the socket are Protobuf3 encoded, but additionally length-prefixed to
facilitate use as a streaming protocol. Protobuf3 doesn't have an
official length-prefix standard, so we use our own. The first byte in
the prefix represents the length of the Big Endian encoded length. The
remaining bytes in the prefix are the Big Endian encoded length.
For example, if the Protobuf3 encoded ABCI message is 0xDEADBEEF (4
bytes), the length-prefixed message is 0x0104DEADBEEF. If the Protobuf3
encoded ABCI message is 65535 bytes long, the length-prefixed message
would be like 0x02FFFF....
Note this prefixing does not apply for grpc.
An ABCI server must also be able to support multiple connections, as
Tendermint uses three connections.
Client
------
There are currently two use-cases for an ABCI client. One is a testing
tool, as in the ``abci-cli``, which allows ABCI requests to be sent via
command line. The other is a consensus engine, such as Tendermint Core,
which makes requests to the application every time a new transaction is
received or a block is committed.
It is unlikely that you will need to implement a client. For details of
our client, see
`here <https://github.com/tendermint/abci/tree/master/client>`__.
Blockchain Protocol
-------------------
In ABCI, a transaction is simply an arbitrary length byte-array. It is
the application's responsibility to define the transaction codec as they
please, and to use it for both CheckTx and DeliverTx.
Note that there are two distinct means for running transactions,
corresponding to stages of 'awareness' of the transaction in the
network. The first stage is when a transaction is received by a
validator from a client into the so-called mempool or transaction pool -
this is where we use CheckTx. The second is when the transaction is
successfully committed on more than 2/3 of validators - where we use
DeliverTx. In the former case, it may not be necessary to run all the
state transitions associated with the transaction, as the transaction
may not ultimately be committed until some much later time, when the
result of its execution will be different. For instance, an Ethereum
ABCI app would check signatures and amounts in CheckTx, but would not
actually execute any contract code until the DeliverTx, so as to avoid
executing state transitions that have not been finalized.
To formalize the distinction further, two explicit ABCI connections are
made between Tendermint Core and the application: the mempool connection
and the consensus connection. We also make a third connection, the query
connection, to query the local state of the app.
Mempool Connection
~~~~~~~~~~~~~~~~~~
The mempool connection is used *only* for CheckTx requests. Transactions
are run using CheckTx in the same order they were received by the
validator. If the CheckTx returns ``OK``, the transaction is kept in
memory and relayed to other peers in the same order it was received.
Otherwise, it is discarded.
CheckTx requests run concurrently with block processing; so they should
run against a copy of the main application state which is reset after
every block. This copy is necessary to track transitions made by a
sequence of CheckTx requests before they are included in a block. When a
block is committed, the application must ensure to reset the mempool
state to the latest committed state. Tendermint Core will then filter
through all transactions in the mempool, removing any that were included
in the block, and re-run the rest using CheckTx against the post-Commit
mempool state.
Consensus Connection
~~~~~~~~~~~~~~~~~~~~
The consensus connection is used only when a new block is committed, and
communicates all information from the block in a series of requests:
``BeginBlock, [DeliverTx, ...], EndBlock, Commit``. That is, when a
block is committed in the consensus, we send a list of DeliverTx
requests (one for each transaction) sandwiched by BeginBlock and
EndBlock requests, and followed by a Commit.
DeliverTx
^^^^^^^^^
DeliverTx is the workhorse of the blockchain. Tendermint sends the
DeliverTx requests asynchronously but in order, and relies on the
underlying socket protocol (ie. TCP) to ensure they are received by the
app in order. They have already been ordered in the global consensus by
the Tendermint protocol.
DeliverTx returns a abci.Result, which includes a Code, Data, and Log.
The code may be non-zero (non-OK), meaning the corresponding transaction
should have been rejected by the mempool, but may have been included in
a block by a Byzantine proposer.
The block header will be updated (TODO) to include some commitment to
the results of DeliverTx, be it a bitarray of non-OK transactions, or a
merkle root of the data returned by the DeliverTx requests, or both.
Commit
^^^^^^
Once all processing of the block is complete, Tendermint sends the
Commit request and blocks waiting for a response. While the mempool may
run concurrently with block processing (the BeginBlock, DeliverTxs, and
EndBlock), it is locked for the Commit request so that its state can be
safely reset during Commit. This means the app *MUST NOT* do any
blocking communication with the mempool (ie. broadcast\_tx) during
Commit, or there will be deadlock. Note also that all remaining
transactions in the mempool are replayed on the mempool connection
(CheckTx) following a commit.
The Commit response includes a byte array, which is the deterministic
state root of the application. It is included in the header of the next
block. It can be used to provide easily verified Merkle-proofs of the
state of the application.
It is expected that the app will persist state to disk on Commit. The
option to have all transactions replayed from some previous block is the
job of the `Handshake <#handshake>`__.
BeginBlock
^^^^^^^^^^
The BeginBlock request can be used to run some code at the beginning of
every block. It also allows Tendermint to send the current block hash
and header to the application, before it sends any of the transactions.
The app should remember the latest height and header (ie. from which it
has run a successful Commit) so that it can tell Tendermint where to
pick up from when it restarts. See information on the Handshake, below.
EndBlock
^^^^^^^^
The EndBlock request can be used to run some code at the end of every
block. Additionally, the response may contain a list of validators,
which can be used to update the validator set. To add a new validator or
update an existing one, simply include them in the list returned in the
EndBlock response. To remove one, include it in the list with a
``power`` equal to ``0``. Tendermint core will take care of updating the
validator set. Note validator set changes are only available in v0.8.0
and up.
Query Connection
~~~~~~~~~~~~~~~~
This connection is used to query the application without engaging
consensus. It's exposed over the tendermint core rpc, so clients can
query the app without exposing a server on the app itself, but they must
serialize each query as a single byte array. Additionally, certain
"standardized" queries may be used to inform local decisions, for
instance about which peers to connect to.
Tendermint Core currently uses the Query connection to filter peers upon
connecting, according to IP address or public key. For instance,
returning non-OK ABCI response to either of the following queries will
cause Tendermint to not connect to the corresponding peer:
- ``p2p/filter/addr/<addr>``, where ``<addr>`` is an IP address.
- ``p2p/filter/pubkey/<pubkey>``, where ``<pubkey>`` is the hex-encoded
ED25519 key of the node (not it's validator key)
Note: these query formats are subject to change!
Handshake
~~~~~~~~~
When the app or tendermint restarts, they need to sync to a common
height. When an ABCI connection is first established, Tendermint will
call ``Info`` on the Query connection. The response should contain the
LastBlockHeight and LastBlockAppHash - the former is the last block for
the which the app ran Commit successfully, the latter is the response
from that Commit.
Using this information, Tendermint will determine what needs to be
replayed, if anything, against the app, to ensure both Tendermint and
the app are synced to the latest block height.
If the app returns a LastBlockHeight of 0, Tendermint will just replay
all blocks.

57
docs/deploy-testnets.rst Normal file
View File

@ -0,0 +1,57 @@
Deploy a Testnet
================
Now that we've seen how ABCI works, and even played with a few
applications on a single validator node, it's time to deploy a test
network to four validator nodes. For this deployment, we'll use the
``basecoin`` application.
Manual Deployments
------------------
It's relatively easy to setup a Tendermint cluster manually. The only
requirements for a particular Tendermint node are a private key for the
validator, stored as ``priv_validator.json``, and a list of the public
keys of all validators, stored as ``genesis.json``. These files should
be stored in ``~/.tendermint``, or wherever the ``$TMROOT`` variable
might be set to.
Here are the steps to setting up a testnet manually:
1) Provision nodes on your cloud provider of choice
2) Install Tendermint and the application of interest on all nodes
3) Generate a private key for each validator using
``tendermint gen_validator``
4) Compile a list of public keys for each validator into a
``genesis.json`` file.
5) Run ``tendermint node --p2p.seeds=< seed addresses >`` on each node,
where ``< seed addresses >`` is a comma separated list of the IP:PORT
combination for each node. The default port for Tendermint is
``46656``. Thus, if the IP addresses of your nodes were
``192.168.0.1, 192.168.0.2, 192.168.0.3, 192.168.0.4``, the command
would look like:
``tendermint node --p2p.seeds=192.168.0.1:46656,192.168.0.2:46656,192.168.0.3:46656,192.168.0.4:46656``.
After a few seconds, all the nodes should connect to eachother and start
making blocks! For more information, see the Tendermint Networks section
of `the guide to using Tendermint </docs/guides/using-tendermint>`__.
Automated Deployments
---------------------
While the manual deployment is easy enough, an automated deployment is
always better. For this, we have the `mintnet-kubernetes
tool <https://github.com/tendermint/tools/tree/master/mintnet-kubernetes>`__,
which allows us to automate the deployment of a Tendermint network on an
already provisioned kubernetes cluster.
For more details, see the `mintnet-kubernetes
directory <https://github.com/tendermint/tools/tree/master/mintnet-kubernetes>`__,
and check out `Google Cloud Platform <https://cloud.google.com/>`__ for
simple provisioning of kubernetes clusters.
Next Steps
----------
Done trying out the testnet? Continue
`onwards </docs/getting-started/next-steps>`__.

291
docs/getting-started.rst Normal file
View File

@ -0,0 +1,291 @@
First Tendermint App
====================
As a general purpose blockchain engine, Tendermint is agnostic to the
application you want to run. So, to run a complete blockchain that does
something useful, you must start two programs: one is Tendermint Core,
the other is your application, which can be written in any programming
language. Recall from `the intro to ABCI </intro/abci-overview>`__ that
Tendermint Core handles all the p2p and consensus stuff, and just
forwards transactions to the application when they need to be validated,
or when they're ready to be committed to a block.
In this guide, we show you some examples of how to run an application
using Tendermint.
**Note:** It is highly recommended to read the `Using Tendermint
Guide <./using-tendermint>`__ prior to working through this
tutorial.
Install
-------
First, make sure you have `installed Tendermint </download>`__. The
first apps we will work with are written in Go. To install them, you
need to `install Go <https://golang.org/doc/install>`__ and `put
``$GOPATH/bin`` in your
``$PATH`` <https://github.com/tendermint/tendermint/wiki/Setting-GOPATH>`__.
Then run
::
go get -u github.com/tendermint/abci/cmd/...
If there is an error, install and run the ``glide`` tool to pin the
dependencies:
::
go get github.com/Masterminds/glide
cd $GOPATH/src/github.com/tendermint/abci
glide install
go install ./cmd/...
Now you should have the ``abci-cli`` plus two apps installed:
::
dummy --help
counter --help
These binaries are installed on ``$GOPATH/bin`` and all come from within
the ``./cmd/...`` directory of the abci repository.
Both of these example applications are in Go. See below for an
application written in Javascript.
Now, let's run some apps!
A First Example - Dummy
-----------------------
The dummy app is a `Merkle
tree <https://en.wikipedia.org/wiki/Merkle_tree>`__ that just stores all
transactions. If the transaction contains an ``=``, eg. ``key=value``,
then the ``value`` is stored under the ``key`` in the Merkle tree.
Otherwise, the full transaction bytes are stored as the key and the
value.
Let's start a dummy application.
::
dummy
In another terminal, we can start Tendermint. If you have never run
Tendermint before, use:
::
tendermint init
tendermint node
If you have used Tendermint, you may want to reset the data for a new
blockchain by running ``tendermint unsafe_reset_all``. Then you can run
``tendermint node`` to start Tendermint, and connect to the app. For
more details, see `the guide on using
Tendermint </docs/guides/using-tendermint>`__.
You should see Tendermint making blocks! We can get the status of our
Tendermint node as follows:
::
curl -s localhost:46657/status
The ``-s`` just silences ``curl``. For nicer output, pipe the result
into a tool like `jq <https://stedolan.github.io/jq/>`__ or
`jsonpp <https://github.com/jmhodges/jsonpp>`__.
Now let's send some transactions to the dummy.
::
curl -s 'localhost:46657/broadcast_tx_commit?tx="abcd"'
Note the single quote (``'``) around the url, which ensures that the
double quotes (``"``) are not escaped by bash. This command sent a
transaction with bytes ``abcd``, so ``abcd`` will be stored as both the
key and the value in the Merkle tree. The response should look something
like:
::
{"jsonrpc":"2.0","id":"","result":[98,{"check_tx":{},"deliver_tx":{}}],"error":""}
The ``98`` is a type-byte, and can be ignored (it's useful for
serializing and deserializing arbitrary json). Otherwise, this result is
empty - there's nothing to report on and everything is OK.
We can confirm that our transaction worked and the value got stored by
querying the app:
::
curl -s 'localhost:46657/abci_query?data="abcd"&path=""&prove=false'
The ``path`` and ``prove`` arguments can be ignored for now, and in a
future release can be left out. The result should look like:
::
{"jsonrpc":"2.0","id":"","result":[112,{"response":{"value":"61626364","log":"exists"}}],"error":""}
Again, the ``112`` is the type-byte. Note the ``value`` in the result
(``61626364``); this is the hex-encoding of the ASCII of ``abcd``. You
can verify this in a python shell by running
``"61626364".decode('hex')``. Stay tuned for a future release that makes
this output more human-readable ;).
Now let's try setting a different key and value:
::
curl -s 'localhost:46657/broadcast_tx_commit?tx="name=satoshi"'
Now if we query for ``name``, we should get ``satoshi``, or
``7361746F736869`` in hex:
::
curl -s 'localhost:46657/abci_query?data="name"&path=""&prove=false'
Try some other transactions and queries to make sure everything is
working!
Another Example - Counter
-------------------------
Now that we've got the hang of it, let's try another application, the
"counter" app.
The counter app doesn't use a Merkle tree, it just counts how many times
we've sent a transaction, or committed the state.
This application has two modes: ``serial=off`` and ``serial=on``.
When ``serial=on``, transactions must be a big-endian encoded
incrementing integer, starting at 0.
If ``serial=off``, there are no restrictions on transactions.
In a live blockchain, transactions collect in memory before they are
committed into blocks. To avoid wasting resources on invalid
transactions, ABCI provides the ``CheckTx`` message, which application
developers can use to accept or reject transactions, before they are
stored in memory or gossipped to other peers.
In this instance of the counter app, with ``serial=on``, ``CheckTx``
only allows transactions whose integer is greater than the last
committed one.
Let's kill the previous instance of ``tendermint`` and the ``dummy``
application, and start the counter app. We can enable ``serial=on`` with
a flag:
::
counter --serial
In another window, reset then start Tendermint:
::
tendermint unsafe_reset_all
tendermint node
Once again, you can see the blocks streaming by. Let's send some
transactions. Since we have set ``serial=on``, the first transaction
must be the number ``0``:
::
curl localhost:46657/broadcast_tx_commit?tx=0x00
Note the empty (hence successful) response. The next transaction must be
the number ``1``. If instead, we try to send a ``5``, we get an error:
::
> curl localhost:46657/broadcast_tx_commit?tx=0x05
{"jsonrpc":"2.0","id":"","result":[98,{"check_tx":{},"deliver_tx":{"code":3,"log":"Invalid nonce. Expected 1, got 5"}}],"error":""}
But if we send a ``1``, it works again:
::
> curl localhost:46657/broadcast_tx_commit?tx=0x01
{"jsonrpc":"2.0","id":"","result":[98,{"check_tx":{},"deliver_tx":{}}],"error":""}
For more details on the ``broadcast_tx`` API, see `the guide on using
Tendermint </docs/guides/using-tendermint>`__.
Example in Another Language - CounterJS
---------------------------------------
We also want to run applications in another language - in this case,
we'll run a Javascript version of the ``counter``. To run it, you'll
need to `install node <https://nodejs.org/en/download/>`__.
You'll also need to fetch the relevant repository, from
https://github.com/tendermint/js-abci then install it. As go devs, we
keep all our code under the ``$GOPATH``, so run:
::
go get github.com/tendermint/js-abci &> /dev/null
cd $GOPATH/src/github.com/tendermint/js-abci/example
npm install
Kill the previous ``counter`` and ``tendermint`` processes. Now run the
app:
::
node example/app.js
In another window, reset and start ``tendermint``:
::
tendermint unsafe_reset_all
tendermint node
Once again, you should see blocks streaming by - but now, our
application is written in javascript! Try sending some transactions, and
like before - the results should be the same:
::
curl localhost:46657/broadcast_tx_commit?tx=0x00 # ok
curl localhost:46657/broadcast_tx_commit?tx=0x05 # invalid nonce
curl localhost:46657/broadcast_tx_commit?tx=0x01 # ok
Neat, eh?
A More Interesting Example - Basecoin
-------------------------------------
Before concluding, we'd like to introduce you to our star application,
`Basecoin <https://github.com/tendermint/basecoin>`__. Unlike the
``dummy`` and ``counter``, which are strictly for example purposes,
``basecoin`` is designed to be actually useful - it's a general purpose
framework for building cryptocurrencies.
The default ``basecoin`` application is a multi-asset cryptocurrency
that supports inter-blockchain communication. For more details on how
basecoin works and how to use it, see our `basecoin
guide <https://github.com/tendermint/basecoin/blob/develop/docs/guide/basecoin-basics.md>`__
Next Step
---------
In this tutorial you learned how to run applications using Tendermint on
a single node. You saw how applications could be written in different
languages, and how to send transactions and query for the latest state.
But the true power of Tendermint comes from its ability to securely and
efficiently run an application across a distributed network of nodes,
while keeping them all in sync using its state-of-the-art consensus
protocol. This is the subject of the next tutorial, where we show you
`how to deploy Tendermint networks <deploy-testnets.rst>`__.

246
docs/getting-started/#02-first-app.md
View File

@ -1,246 +0,0 @@
# First Tendermint App
As a general purpose blockchain engine, Tendermint is agnostic to the application you want to run.
So, to run a complete blockchain that does something useful, you must start two programs:
one is Tendermint Core, the other is your application, which can be written in any programming language.
Recall from [the intro to ABCI](/intro/abci-overview) that Tendermint Core handles all the p2p and consensus stuff,
and just forwards transactions to the application when they need to be validated, or when they're ready to be committed to a block.
In this guide, we show you some examples of how to run an application using Tendermint.
**Note:** It is highly recommended to read the [Using Tendermint Guide](/docs/guides/using-tendermint) prior to working through this tutorial.
## Install
First, make sure you have [installed Tendermint](/download).
The first apps we will work with are written in Go.
To install them, you need to [install Go](https://golang.org/doc/install) and
[put `$GOPATH/bin` in your `$PATH`](https://github.com/tendermint/tendermint/wiki/Setting-GOPATH).
Then run
```
go get -u github.com/tendermint/abci/cmd/...
```
If there is an error, install and run the `glide` tool to pin the dependencies:
```
go get github.com/Masterminds/glide
cd $GOPATH/src/github.com/tendermint/abci
glide install
go install ./cmd/...
```
Now you should have the `abci-cli` plus two apps installed:
```
dummy --help
counter --help
```
These binaries are installed on `$GOPATH/bin` and all come from within the `./cmd/...` directory of the abci repository.
Both of these example applications are in Go. See below for an application written in Javascript.
Now, let's run some apps!
## A First Example - Dummy
The dummy app is a [Merkle tree](https://en.wikipedia.org/wiki/Merkle_tree) that just stores all transactions.
If the transaction contains an `=`, eg. `key=value`,
then the `value` is stored under the `key` in the Merkle tree.
Otherwise, the full transaction bytes are stored as the key and the value.
Let's start a dummy application.
```
dummy
```
In another terminal, we can start Tendermint.
If you have never run Tendermint before, use:
```
tendermint init
tendermint node
```
If you have used Tendermint, you may want to reset the data for a new blockchain by running `tendermint unsafe_reset_all`.
Then you can run `tendermint node` to start Tendermint, and connect to the app.
For more details, see [the guide on using Tendermint](/docs/guides/using-tendermint).
You should see Tendermint making blocks!
We can get the status of our Tendermint node as follows:
```
curl -s localhost:46657/status
```
The `-s` just silences `curl`. For nicer output, pipe the result into a tool like [jq](https://stedolan.github.io/jq/)
or [jsonpp](https://github.com/jmhodges/jsonpp).
Now let's send some transactions to the dummy.
```
curl -s 'localhost:46657/broadcast_tx_commit?tx="abcd"'
```
Note the single quote (`'`) around the url, which ensures that the double quotes (`"`) are not escaped by bash.
This command sent a transaction with bytes `abcd`, so `abcd` will be stored as both the key and the value in the Merkle tree.
The response should look something like:
```
{"jsonrpc":"2.0","id":"","result":[98,{"check_tx":{},"deliver_tx":{}}],"error":""}
```
The `98` is a type-byte, and can be ignored (it's useful for serializing and deserializing arbitrary json).
Otherwise, this result is empty - there's nothing to report on and everything is OK.
We can confirm that our transaction worked and the value got stored by querying the app:
```
curl -s 'localhost:46657/abci_query?data="abcd"&path=""&prove=false'
```
The `path` and `prove` arguments can be ignored for now, and in a future release can be left out.
The result should look like:
```
{"jsonrpc":"2.0","id":"","result":[112,{"response":{"value":"61626364","log":"exists"}}],"error":""}
```
Again, the `112` is the type-byte. Note the `value` in the result (`61626364`); this is the hex-encoding of the ASCII of `abcd`.
You can verify this in a python shell by running `"61626364".decode('hex')`.
Stay tuned for a future release that makes this output more human-readable ;).
Now let's try setting a different key and value:
```
curl -s 'localhost:46657/broadcast_tx_commit?tx="name=satoshi"'
```
Now if we query for `name`, we should get `satoshi`, or `7361746F736869` in hex:
```
curl -s 'localhost:46657/abci_query?data="name"&path=""&prove=false'
```
Try some other transactions and queries to make sure everything is working!
## Another Example - Counter
Now that we've got the hang of it, let's try another application, the "counter" app.
The counter app doesn't use a Merkle tree, it just counts how many times we've sent a transaction,
or committed the state.
This application has two modes: `serial=off` and `serial=on`.
When `serial=on`, transactions must be a big-endian encoded incrementing integer, starting at 0.
If `serial=off`, there are no restrictions on transactions.
In a live blockchain, transactions collect in memory before they are committed into blocks.
To avoid wasting resources on invalid transactions,
ABCI provides the `CheckTx` message,
which application developers can use to accept or reject transactions,
before they are stored in memory or gossipped to other peers.
In this instance of the counter app, with `serial=on`, `CheckTx` only allows transactions whose integer is greater than the last committed one.
Let's kill the previous instance of `tendermint` and the `dummy` application, and start the counter app.
We can enable `serial=on` with a flag:
```
counter --serial
```
In another window, reset then start Tendermint:
```
tendermint unsafe_reset_all
tendermint node
```
Once again, you can see the blocks streaming by. Let's send some transactions.
Since we have set `serial=on`, the first transaction must be the number `0`:
```
curl localhost:46657/broadcast_tx_commit?tx=0x00
```
Note the empty (hence successful) response.
The next transaction must be the number `1`. If instead, we try to send a `5`, we get an error:
```
> curl localhost:46657/broadcast_tx_commit?tx=0x05
{"jsonrpc":"2.0","id":"","result":[98,{"check_tx":{},"deliver_tx":{"code":3,"log":"Invalid nonce. Expected 1, got 5"}}],"error":""}
```
But if we send a `1`, it works again:
```
> curl localhost:46657/broadcast_tx_commit?tx=0x01
{"jsonrpc":"2.0","id":"","result":[98,{"check_tx":{},"deliver_tx":{}}],"error":""}
```
For more details on the `broadcast_tx` API,
see [the guide on using Tendermint](/docs/guides/using-tendermint).
## Example in Another Language - CounterJS
We also want to run applications in another language - in this case, we'll run a Javascript version of the `counter`.
To run it, you'll need to [install node](https://nodejs.org/en/download/).
You'll also need to fetch the relevant repository, from https://github.com/tendermint/js-abci then install it.
As go devs, we keep all our code under the `$GOPATH`, so run:
```
go get github.com/tendermint/js-abci &> /dev/null
cd $GOPATH/src/github.com/tendermint/js-abci/example
npm install
```
Kill the previous `counter` and `tendermint` processes. Now run the app:
```
node example/app.js
```
In another window, reset and start `tendermint`:
```
tendermint unsafe_reset_all
tendermint node
```
Once again, you should see blocks streaming by - but now, our application is written in javascript!
Try sending some transactions, and like before - the results should be the same:
```
curl localhost:46657/broadcast_tx_commit?tx=0x00 # ok
curl localhost:46657/broadcast_tx_commit?tx=0x05 # invalid nonce
curl localhost:46657/broadcast_tx_commit?tx=0x01 # ok
```
Neat, eh?
## A More Interesting Example - Basecoin
Before concluding, we'd like to introduce you to our star application, [Basecoin](https://github.com/tendermint/basecoin).
Unlike the `dummy` and `counter`, which are strictly for example purposes,
`basecoin` is designed to be actually useful - it's a general purpose framework for building cryptocurrencies.
The default `basecoin` application is a multi-asset cryptocurrency that supports inter-blockchain communication.
For more details on how basecoin works and how to use it, see our [basecoin guide](https://github.com/tendermint/basecoin/blob/develop/docs/guide/basecoin-basics.md)
## Next Step
In this tutorial you learned how to run applications using Tendermint on a single node.
You saw how applications could be written in different languages,
and how to send transactions and query for the latest state.
But the true power of Tendermint comes from its ability to securely and efficiently run an application
across a distributed network of nodes, while keeping them all in sync using its state-of-the-art consensus protocol.
This is the subject of the next tutorial, where we show you [how to deploy Tendermint networks](/docs/getting-started/deploy-testnet).

39
docs/getting-started/#03-deploy-testnet.md
View File

@ -1,39 +0,0 @@
# Deploy a Testnet
Now that we've seen how ABCI works, and even played with a few applications on a single validator node,
it's time to deploy a test network to four validator nodes.
For this deployment, we'll use the `basecoin` application.
## Manual Deployments
It's relatively easy to setup a Tendermint cluster manually.
The only requirements for a particular Tendermint node are a private key for the validator,
stored as `priv_validator.json`, and a list of the public keys of all validators, stored as `genesis.json`.
These files should be stored in `~/.tendermint`, or wherever the `$TMROOT` variable might be set to.
Here are the steps to setting up a testnet manually:
1) Provision nodes on your cloud provider of choice
2) Install Tendermint and the application of interest on all nodes
3) Generate a private key for each validator using `tendermint gen_validator`
4) Compile a list of public keys for each validator into a `genesis.json` file.
5) Run `tendermint node --p2p.seeds=< seed addresses >` on each node, where `< seed addresses >` is a
comma separated list of the IP:PORT combination for each node. The default port for Tendermint is `46656`.
Thus, if the IP addresses of your nodes were `192.168.0.1, 192.168.0.2, 192.168.0.3, 192.168.0.4`,
the command would look like: `tendermint node --p2p.seeds=192.168.0.1:46656,192.168.0.2:46656,192.168.0.3:46656,192.168.0.4:46656`.
After a few seconds, all the nodes should connect to eachother and start making blocks!
For more information, see the Tendermint Networks section of [the guide to using Tendermint](/docs/guides/using-tendermint).
## Automated Deployments
While the manual deployment is easy enough, an automated deployment is always better.
For this, we have the [mintnet-kubernetes tool](https://github.com/tendermint/tools/tree/master/mintnet-kubernetes),
which allows us to automate the deployment of a Tendermint network on an already provisioned kubernetes cluster.
For more details, see the [mintnet-kubernetes directory](https://github.com/tendermint/tools/tree/master/mintnet-kubernetes),
and check out [Google Cloud Platform](https://cloud.google.com/) for simple provisioning of kubernetes clusters.
## Next Steps
Done trying out the testnet? Continue [onwards](/docs/getting-started/next-steps).

21
docs/getting-started/#04-next-steps.md
View File

@ -1,21 +0,0 @@
# Next Steps
By now you've seen how to run a simple example ABCI application on a local Tendermint node
and on a remote Tendermint cluster.
To learn more about building ABCI applications and integrating with Tendermint, see the [Developer Guides](/docs/guides/app-development).
To learn more about running the Tendermint software, see the [Using Tendermint Guide](/docs/guides/using-tendermint).
To learn more about Tendermint's various pieces, check out the [Documentation](/docs).
For a deeper dive, see [this thesis](https://atrium.lib.uoguelph.ca/xmlui/handle/10214/9769).
There is also the [original whitepaper](/static/docs/tendermint.pdf), though it is now quite outdated.
The Tendermint [Software Ecosystem](/ecosystem) contains many example applications and related software built by the Tendermint team and others. Check it out for some inspiration!
For details on how the software has changed, and what changes are in store, see the [Changelog](/docs/changelog) and the [Roadmap](/docs/roadmap).
See our [Community](/community) page for more ways to collaborate.
You can also [get in touch with the team](/contact).
Most importantly, enjoy!

219
docs/guides/abci-cli.md
View File

@ -1,219 +0,0 @@
# Using the abci-cli
To facilitate testing and debugging of ABCI servers and simple apps,
we built a CLI, the `abci-cli`, for sending ABCI messages from the command line.
## Install
Make sure you [have Go installed](https://golang.org/doc/install) and [put `$GOPATH/bin` in your `$PATH`](https://github.com/tendermint/tendermint/wiki/Setting-GOPATH).
Next, install the `abci-cli` tool and example applications:
```
go get -u github.com/tendermint/abci/cmd/...
```
If this fails, you may need to use `glide` to get vendored dependencies:
```
go get github.com/Masterminds/glide
cd $GOPATH/src/github.com/tendermint/abci
glide install
go install ./cmd/...
```
Now run `abci-cli --help` to see the list of commands:
```
COMMANDS:
batch Run a batch of ABCI commands against an application
console Start an interactive console for multiple commands
echo Have the application echo a message
info Get some info about the application
set_option Set an option on the application
deliver_tx Append a new tx to application
check_tx Validate a tx
commit Get application Merkle root hash
help, h Shows a list of commands or help for one command
GLOBAL OPTIONS:
--address "tcp://127.0.0.1:46658" address of application socket
--help, -h show help
--version, -v print the version
```
## First Example - Dummy
The `abci-cli` tool lets us send ABCI messages to our application, to help build and debug them.
The most important messages are `deliver_tx`, `check_tx`, and `commit`,
but there are others for convenience, configuration, and information purposes.
Let's start a dummy application, which was installed at the same time as `abci-cli` above. The dummy just stores transactions in a merkle tree:
```
dummy
```
In another terminal, run
```
abci-cli echo hello
abci-cli info
```
The application should echo `hello` and give you some information about itself.
An ABCI application must provide two things:
- a socket server
- a handler for ABCI messages
When we run the `abci-cli` tool we open a new connection to the application's socket server,
send the given ABCI message, and wait for a response.
The server may be generic for a particular language, and we provide a [reference implementation
in Golang](https://github.com/tendermint/abci/tree/master/server).
See the [list of other ABCI implementations](https://tendermint.com/ecosystem)
for servers in other languages.
The handler is specific to the application, and may be arbitrary,
so long as it is deterministic and conforms to the ABCI interface specification.
So when we run `abci-cli info`, we open a new connection to the ABCI server, which calls the `Info()` method on the application, which tells us the number of transactions in our Merkle tree.
Now, since every command opens a new connection, we provide the `abci-cli console` and `abci-cli batch` commands,
to allow multiple ABCI messages to be sent over a single connection.
Running `abci-cli console` should drop you in an interactive console for speaking ABCI messages to your application.
Try running these commands:
```
> echo hello
-> data: hello
> info
-> data: {"size":0}
> commit
-> data: 0x
> deliver_tx "abc"
-> code: OK
> info
-> data: {"size":1}
> commit
-> data: 0x750502FC7E84BBD788ED589624F06CFA871845D1
> query "abc"
-> code: OK
-> data: {"index":0,"value":"abc","exists":true}
> deliver_tx "def=xyz"
-> code: OK
> commit
-> data: 0x76393B8A182E450286B0694C629ECB51B286EFD5
> query "def"
-> code: OK
-> data: {"index":1,"value":"xyz","exists":true}
```
Note that if we do `deliver_tx "abc"` it will store `(abc, abc)`,
but if we do `deliver_tx "abc=efg"` it will store `(abc, efg)`.
Similarly, you could put the commands in a file and run `abci-cli --verbose batch < myfile`.
## Another Example - Counter
Now that we've got the hang of it, let's try another application, the "counter" app.
The counter app doesn't use a Merkle tree, it just counts how many times we've sent a transaction,
asked for a hash, or committed the state. The result of `commit` is just the number of transactions sent.
This application has two modes: `serial=off` and `serial=on`.
When `serial=on`, transactions must be a big-endian encoded incrementing integer, starting at 0.
If `serial=off`, there are no restrictions on transactions.
We can toggle the value of `serial` using the `set_option` ABCI message.
When `serial=on`, some transactions are invalid.
In a live blockchain, transactions collect in memory before they are committed into blocks.
To avoid wasting resources on invalid transactions,
ABCI provides the `check_tx` message,
which application developers can use to accept or reject transactions,
before they are stored in memory or gossipped to other peers.
In this instance of the counter app, `check_tx` only allows transactions whose integer is greater than the last committed one.
Let's kill the console and the dummy application, and start the counter app:
```
counter
```
In another window, start the `abci-cli console`:
```
> set_option serial on
-> data: serial=on
> check_tx 0x00
-> code: OK
> check_tx 0xff
-> code: OK
> deliver_tx 0x00
-> code: OK
> check_tx 0x00
-> code: BadNonce
-> log: Invalid nonce. Expected >= 1, got 0
> deliver_tx 0x01
-> code: OK
> deliver_tx 0x04
-> code: BadNonce
-> log: Invalid nonce. Expected 2, got 4
> info
-> data: {"hashes":0,"txs":2}
```
This is a very simple application, but between `counter` and `dummy`, its easy to see how you can build out arbitrary application states on top of the ABCI.
[Hyperledger's Burrow](https://github.com/hyperledger/burrow) also runs atop ABCI, bringing with it Ethereum-like accounts, the Ethereum virtual-machine, Monax's permissioning scheme, and native contracts extensions.
But the ultimate flexibility comes from being able to write the application easily in any language.
We have implemented the counter in a number of languages (see the example directory).
To run the Node JS version, `cd` to `example/js` and run
```
node app.js
```
(you'll have to kill the other counter application process).
In another window, run the console and those previous ABCI commands.
You should get the same results as for the Go version.
Want to write the counter app in your favorite language?! We'd be happy to add you to our [ecosystem](https://tendermint.com/ecosystem)! We're also offering [bounties](https://tendermint.com/bounties) for implementations in new languages!
## Notes
The `abci-cli` is designed strictly for testing and debugging.
In a real deployment, the role of sending messages is taken by Tendermint,
which connects to the app using three separate connections,
each with its own pattern of messages.
For more information, see the [application developers guide](/docs/guides/app-development).
For examples of running an ABCI app with Tendermint, see the [introductory guide](/docs/getting-started/first-abci-app).

64
docs/guides/app-architecture.md
View File

@ -1,64 +0,0 @@
# Application Architecture Guide
## Overview
A blockchain application is more than the consensus engine and the transaction logic (eg. smart contracts, business logic) as implemented in the ABCI app. There are also (mobile, web, desktop) clients that will need to connect and make use of the app. We will assume for now that you have a well designed transactions and database model, but maybe this will be the topic of another article. This article is more interested in various ways of setting up the "plumbing" and connecting these pieces, and demonstrating some evolving best practices.
## Security
A very important aspect when constructing a blockchain is security. The consensus model can be DoSed (no consensus possible) by corrupting 1/3 of the validators and exploited (writing arbitrary blocks) by corrupting 2/3 of the validators. So, while the security is not that of the "weakest link", you should take care that the "average link" is sufficiently hardened.
One big attack surface on the validators is the communication between the ABCI app and the tendermint core. This should be highly protected. Ideally, the app and the core are running on the same machine, so no external agent can target the communication channel. You can use unix sockets (with permissions preventing access from other users), or even compile the two apps into one binary if the ABCI app is also writen in go. If you are unable to do that due to language support, then the ABCI app should bind a TCP connection to localhost (127.0.0.1), which is less efficient and secure, but still not reachable from outside. If you must run the ABCI app and tendermint core on separate machines, make sure you have a secure communication channel (ssh tunnel?)
Now assuming, you have linked together your app and the core securely, you must also make sure no one can get on the machine it is hosted on. At this point it is basic network security. Run on a secure operating system (SELinux?). Limit who has access to the machine (user accounts, but also where the physical machine is hosted). Turn off all services except for ssh, which should only be accessible by some well-guarded public/private key pairs (no password). And maybe even firewall off access to the ports used by the validators, so only known validators can connect.
There was also a suggestion on slack from @jhon about compiling everything together with a unikernel for more security, such as [Mirage](https://mirage.io) or [UNIK](https://github.com/emc-advanced-dev/unik).
## Connecting your client to the blockchain
### Tendermint Core RPC
The concept is that the ABCI app is completely hidden from the outside world and only communicated through a tested and secured [interface exposed by the tendermint core](/docs/specs/rpc). This interface exposes a lot of data on the block header and consensus process, which is quite useful for externally verifying the system. It also includes 3(!) methods to broadcast a transaction (propose it for the blockchain, and possibly await a response). And one method to query app-specific data from the ABCI application.
Pros:
* Server code already written
* Access to block headers to validate merkle proofs (nice for light clients)
* Basic read/write functionality is supported
Cons:
* Limited interface to app. All queries must be serialized into []byte (less expressive than JSON over HTTP) and there is no way to push data from ABCI app to the client (eg. notify me if account X receives a transaction)
### Custom ABCI server
This was proposed by @wolfposd on slack and demonstrated by [TMChat](https://github.com/wolfposd/TMChat), a sample app. The concept is to write a custom server for your app (with typical REST API/websockets/etc for easy use by a mobile app). This custom server is in the same binary as the ABCI app and data store, so can easily react to complex events there that involve understanding the data format (send a message if my balance drops below 500). All "writes" sent to this server are proxied via websocket/JSON-RPC to tendermint core. When they come back as deliver_tx over ABCI, they will be written to the data store. For "reads", we can do any queries we wish that are supported by our architecture, using any web technology that is useful. The general architecture is shown in the following diagram:
<img alt="Application Architecture" src="../assets/images/tm-app-example.png">
Pros:
* Separates application logic from blockchain logic
* Allows much richer, more flexible client-facing API
* Allows pub-sub, watching certain fields, etc.
Cons:
* Access to ABCI app can be dangerous (be VERY careful not to write unless it comes from the validator node)
* No direct access to the blockchain headers to verify tx
* You must write your own API (but maybe that's a pro...)
### Hybrid solutions
Likely the least secure but most versatile. The client can access both the tendermint node for all blockchain info, as well as a custom app server, for complex queries and pub-sub on the abci app.
Pros:
* All from both above solutions
Cons:
* Even more complexity
* Even more attack vectors (less security)
## Scalability
Read replica using non-validating nodes? They could forward transactions to the validators (fewer connections, more security), and locally allow all queries in any of the above configurations. Thus, while transaction-processing speed is limited by the speed of the abci app and the number of validators, one should be able to scale our read performance to quite an extent (until the replication process drains too many resources from the validator nodes).
## Example Code
* [TMChat](https://github.com/wolfposd/TMChat)

155
docs/guides/app-development.md
View File

@ -1,155 +0,0 @@
# Application Development Guide
## ABCI Design
The purpose of ABCI is to provide a clean interface between state transition machines on one computer and the mechanics of their replication across multiple computers. The former we call 'application logic' and the latter the 'consensus engine'. Application logic validates transactions and optionally executes transactions against some persistent state. A consensus engine ensures all transactions are replicated in the same order on every machine. We call each machine in a consensus engine a 'validator', and each validator runs the same transactions through the same application logic. In particular, we are interested in blockchain-style consensus engines, where transactions are committed in hash-linked blocks.
The ABCI design has a few distinct components:
- message protocol
- pairs of request and response messages
- consensus makes requests, application responds
- defined using protobuf
- server/client
- consensus engine runs the client
- application runs the server
- two implementations:
- async raw bytes
- grpc
- blockchain protocol
- abci is connection oriented
- Tendermint Core maintains three connections:
- [mempool connection](#mempool-connection): for checking if transactions should be relayed before they are committed; only uses `CheckTx`
- [consensus connection](#consensus-connection): for executing transactions that have been committed. Message sequence is - for every block - `BeginBlock, [DeliverTx, ...], EndBlock, Commit`
- [query connection](#query-connection): for querying the application state; only uses Query and Info
<img src="../assets/images/abci.png">
The mempool and consensus logic act as clients, and each maintains an open ABCI connection with the application, which hosts an ABCI server. Shown are the request and response types sent on each connection.
## Message Protocol
The message protocol consists of pairs of requests and responses. Some messages have no fields, while others may include byte-arrays, strings, or integers. See the `message Request` and `message Response` definitions in [the protobuf definition file](https://github.com/tendermint/abci/blob/master/types/types.proto), and the [protobuf documentation](https://developers.google.com/protocol-buffers/docs/overview) for more details.
For each request, a server should respond with the corresponding response, where order of requests is preserved in the order of responses.
## Server
To use ABCI in your programming language of choice, there must be a ABCI server in that language.
Tendermint supports two kinds of implementation of the server:
- Asynchronous, raw socket server (Tendermint Socket Protocol, also known as TSP or Teaspoon)
- GRPC
Both can be tested using the `abci-cli` by setting the `--abci` flag appropriately (ie. to `socket` or `grpc`).
See examples, in various stages of maintenance, in [Go](https://github.com/tendermint/abci/tree/master/server), [JavaScript](https://github.com/tendermint/js-abci), [Python](https://github.com/tendermint/abci/tree/master/example/python3/abci), [C++](https://github.com/mdyring/cpp-tmsp), and [Java](https://github.com/jTendermint/jabci).
### GRPC
If GRPC is available in your language, this is the easiest approach,
though it will have significant performance overhead.
To get started with GRPC, copy in the [protobuf file](https://github.com/tendermint/abci/blob/master/types/types.proto) and compile it using the GRPC plugin for your language.
For instance, for golang, the command is `protoc --go_out=plugins=grpc:. types.proto`. See the [grpc documentation for more details](http://www.grpc.io/docs/). `protoc` will autogenerate all the necessary code for ABCI client and server in your language, including whatever interface your application must satisfy to be used by the ABCI server for handling requests.
### TSP
If GRPC is not available in your language, or you require higher performance, or otherwise enjoy programming, you may implement your own ABCI server
using the Tendermint Socket Protocol, known affectionaltely as Teaspoon.
The first step is still to auto-generate the relevant data types and codec in your language using `protoc`.
Messages coming over the socket are Protobuf3 encoded, but additionally length-prefixed to facilitate use as a streaming protocol. Protobuf3 doesn't have an official length-prefix standard, so we use our own. The first byte in the prefix represents the length of the Big Endian encoded length. The remaining bytes in the prefix are the Big Endian encoded length.
For example, if the Protobuf3 encoded ABCI message is 0xDEADBEEF (4 bytes), the length-prefixed message is 0x0104DEADBEEF. If the Protobuf3 encoded ABCI message is 65535 bytes long, the length-prefixed message would be like 0x02FFFF....
Note this prefixing does not apply for grpc.
An ABCI server must also be able to support multiple connections, as Tendermint uses three connections.
## Client
There are currently two use-cases for an ABCI client.
One is a testing tool, as in the `abci-cli`, which allows ABCI requests to be sent via command line.
The other is a consensus engine, such as Tendermint Core, which makes requests to the application every time a new transaction is received or a block is committed.
It is unlikely that you will need to implement a client. For details of our client, see [here](https://github.com/tendermint/abci/tree/master/client).
## Blockchain Protocol
In ABCI, a transaction is simply an arbitrary length byte-array.
It is the application's responsibility to define the transaction codec as they please,
and to use it for both CheckTx and DeliverTx.
Note that there are two distinct means for running transactions, corresponding to stages of 'awareness'
of the transaction in the network. The first stage is when a transaction is received by a validator from a client into the so-called mempool or transaction pool - this is where we use CheckTx. The second is when the transaction is successfully committed on more than 2/3 of validators - where we use DeliverTx. In the former case, it may not be necessary to run all the state transitions associated with the transaction, as the transaction may not ultimately be committed until some much later time, when the result of its execution will be different.
For instance, an Ethereum ABCI app would check signatures and amounts in CheckTx, but would not actually execute any contract code until the DeliverTx, so as to avoid executing state transitions that have not been finalized.
To formalize the distinction further, two explicit ABCI connections are made between Tendermint Core and the application: the mempool connection and the consensus connection. We also make a third connection, the query connection, to query the local state of the app.
### Mempool Connection
The mempool connection is used *only* for CheckTx requests.
Transactions are run using CheckTx in the same order they were received by the validator.
If the CheckTx returns `OK`, the transaction is kept in memory and relayed to other peers in the same order it was received. Otherwise, it is discarded.
CheckTx requests run concurrently with block processing;
so they should run against a copy of the main application state which is reset after every block.
This copy is necessary to track transitions made by a sequence of CheckTx requests before they are included in a block. When a block is committed, the application must ensure to reset the mempool state to the latest committed state. Tendermint Core will then filter through all transactions in the mempool, removing any that were included in the block, and re-run the rest using CheckTx against the post-Commit mempool state.
### Consensus Connection
The consensus connection is used only when a new block is committed, and communicates all information from the block in a series of requests: `BeginBlock, [DeliverTx, ...], EndBlock, Commit`.
That is, when a block is committed in the consensus, we send a list of DeliverTx requests (one for each transaction) sandwiched by BeginBlock and EndBlock requests, and followed by a Commit.
#### DeliverTx
DeliverTx is the workhorse of the blockchain. Tendermint sends the DeliverTx requests asynchronously but in order,
and relies on the underlying socket protocol (ie. TCP) to ensure they are received by the app in order. They have already been ordered in the global consensus by the Tendermint protocol.
DeliverTx returns a abci.Result, which includes a Code, Data, and Log. The code may be non-zero (non-OK), meaning the corresponding transaction should have been rejected by the mempool,
but may have been included in a block by a Byzantine proposer.
The block header will be updated (TODO) to include some commitment to the results of DeliverTx, be it a bitarray of non-OK transactions, or a merkle root of the data returned by the DeliverTx requests, or both.
#### Commit
Once all processing of the block is complete, Tendermint sends the Commit request and blocks waiting
for a response. While the mempool may run concurrently with block processing (the BeginBlock, DeliverTxs, and EndBlock), it is locked for the Commit request so that its state can be safely reset during Commit. This means the app *MUST NOT* do any blocking communication with the mempool (ie. broadcast_tx) during Commit, or there will be deadlock. Note also that all remaining transactions in the mempool are replayed on the mempool connection (CheckTx) following a commit.
The Commit response includes a byte array, which is the deterministic state root of the application. It is included in the header of the next block. It can be used to provide easily verified Merkle-proofs of the state of the application.
It is expected that the app will persist state to disk on Commit. The option to have all transactions replayed from some previous block is the job of the [Handshake](#handshake).
#### BeginBlock
The BeginBlock request can be used to run some code at the beginning of every block. It also allows Tendermint to send the current block hash and header to the application, before it sends any of the transactions.
The app should remember the latest height and header (ie. from which it has run a successful Commit) so that it can tell Tendermint where to pick up from when it restarts. See information on the Handshake, below.
#### EndBlock
The EndBlock request can be used to run some code at the end of every block. Additionally, the response may contain a list of validators, which can be used to update the validator set. To add a new validator or update an existing one, simply include them in the list returned in the EndBlock response. To remove one, include it in the list with a `power` equal to `0`. Tendermint core will take care of updating the validator set. Note validator set changes are only available in v0.8.0 and up.
### Query Connection
This connection is used to query the application without engaging consensus. It's exposed over the tendermint core rpc, so clients can query the app without exposing a server on the app itself, but they must serialize each query as a single byte array. Additionally, certain "standardized" queries may be used to inform local decisions, for instance about which peers to connect to.
Tendermint Core currently uses the Query connection to filter peers upon connecting, according to IP address or public key. For instance, returning non-OK ABCI response to either of the following queries will cause Tendermint to not connect to the corresponding peer:
- `p2p/filter/addr/<addr>`, where `<addr>` is an IP address.
- `p2p/filter/pubkey/<pubkey>`, where `<pubkey>` is the hex-encoded ED25519 key of the node (not it's validator key)
Note: these query formats are subject to change!
### Handshake
When the app or tendermint restarts, they need to sync to a common height.
When an ABCI connection is first established, Tendermint will call `Info` on the Query connection.
The response should contain the LastBlockHeight and LastBlockAppHash
- the former is the last block for the which the app ran Commit successfully,
the latter is the response from that Commit.
Using this information, Tendermint will determine what needs to be replayed, if anything, against the app,
to ensure both Tendermint and the app are synced to the latest block height.
If the app returns a LastBlockHeight of 0, Tendermint will just replay all blocks.

100
docs/guides/install-from-source.md
View File

@ -1,100 +0,0 @@
# Install from Source
This page provides instructions on installing Tendermint from source.
To download pre-built binaries, see the [Download page](/download).
## Install Go
Make sure you have [installed Go](https://golang.org/doc/install) and set the `GOPATH`.
## Install Tendermint
You should be able to install the latest with a simple
```
go get github.com/tendermint/tendermint/cmd/tendermint
```
Run `tendermint --help` for more.
If the installation failed, a dependency may been updated and become incompatible with the latest Tendermint master branch.
We solve this using the `glide` tool for dependency management.
Fist, install `glide`:
```
go get github.com/Masterminds/glide
```
Now we can fetch the correct versions of each dependency by running:
```
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint
```
Note that even though `go get` originally failed,
the repository was still cloned to the correct location in the `$GOPATH`.
The latest Tendermint Core version is now installed.
### Reinstall
If you already have Tendermint installed, and you make updates,
simply
```
cd $GOPATH/src/github.com/tendermint/tendermint
go install ./cmd/tendermint
```
To upgrade, there are a few options:
- set a new `$GOPATH` and run `go get github.com/tendermint/tendermint/cmd/tendermint`. This makes a fresh copy of everything for the new version.
- run `go get -u github.com/tendermint/tendermint/cmd/tendermint`, where the `-u` fetches the latest updates for the repository and its dependencies
- fetch and checkout the latest master branch in `$GOPATH/src/github.com/tendermint/tendermint`, and then run `glide install && go install ./cmd/tendermint` as above.
Note the first two options should usually work, but may fail.
If they do, use `glide`, as above:
```
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint
```
Since the third option just uses `glide` right away, it should always work.
### Troubleshooting
If `go get` failing bothers you, fetch the code using `git`:
```
mkdir -p $GOPATH/src/github.com/tendermint
git clone https://github.com/tendermint/tendermint $GOPATH/src/github.com/tendermint/tendermint
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint
```
### Run
To start a one-node blockchain with a simple in-process application:
```
tendermint init
tendermint node --proxy_app=dummy
```
See the
[App Development](/docs/guides/app-development)
guide for more details on building applications,
and the
[Using Tendermint](/docs/guides/using-tendermint)
guide for more details about using the `tendermint` program.
## Next Step
Learn how to [create your first ABCI app](/docs/getting-started/first-abci-app).

306
docs/guides/using-tendermint.md
View File

@ -1,306 +0,0 @@
# Using Tendermint
This is a guide to using the `tendermint` program from the command line.
It assumes only that you [have tendermint installed](/download) and have some rudimentary idea
of what Tendermint and ABCI are.
You can see the help menu with `tendermint --help`, and the version number with `tendermint version`.
## Directory Root
The default directory for blockchain data is `~/.tendermint`. Override this by setting the `TMROOT` environment variable.
## Initialize
Initialize the root directory by running:
```
tendermint init
```
This will create a new private key (`priv_validator.json`), and a genesis file (`genesis.json`) containing the associated public key.
This is all that's necessary to run a local testnet with one validator.
For more elaborate initialization, see our [testnet deployment tool](https://github.com/tendermint/tools/tree/master/mintnet-kubernetes).
## Run
To run a tendermint node, use
```
tendermint node
```
By default, Tendermint will try to connect to a abci appliction on [127.0.0.1:46658](127.0.0.1:46658).
If you have the `dummy` ABCI app installed, run it in another window.
If you don't, kill tendermint and run an in-process version with
```
tendermint node --proxy_app=dummy
```
After a few seconds you should see blocks start streaming in.
Note that blocks are produced regularly, even if there are no transactions.
This changes [with this pull request](https://github.com/tendermint/tendermint/pull/584).
Tendermint supports in-process versions of the dummy, counter, and nil apps that ship as examples in the [ABCI repository](https://github.com/tendermint/abci).
It's easy to compile your own app in-process with tendermint if it's written in Go.
If your app is not written in Go, simply run it in another process,
and use the `--proxy_app` flag to specify the address of the socket it is listening on, for instance
```
tendermint node --proxy_app=/var/run/abci.sock
```
## Transactions
To send a transaction, use `curl` to make requests to the Tendermint RPC server:
```
curl http://localhost:46657/broadcast_tx_commit?tx=\"abcd\"
```
For handling responses, we recommend you [install the jsonpp tool](http://jmhodges.github.io/jsonpp/) to pretty print the JSON.
We can see the chain's status at the `/status` end-point:
```
curl http://localhost:46657/status | jsonpp
```
and the `latest_app_hash` in particular:
```
curl http://localhost:46657/status | jsonpp | grep app_hash
```
Visit [http://localhost:46657](http://localhost:46657) in your browser to see the list of other endpoints.
Some take no arguments (like `/status`), while others specify the argument name and use `_` as a placeholder.
## Reset
**WARNING: UNSAFE** Only do this in development and only if you can afford to lose all blockchain data!
To reset a blockchain, stop the node, remove the `~/.tendermint/data` directory and run
```
tendermint unsafe_reset_priv_validator
```
This final step is necessary to reset the `priv_validator.json`,
which otherwise prevents you from making conflicting votes in the consensus
(something that could get you in trouble if you do it on a real blockchain).
If you don't reset the `priv_validator.json`, your fresh new blockchain will not make any blocks.
## Configuration
Tendermint uses a `config.toml` for configutation. For details, see [the documentation](/docs/specs/configuration).
Notable options include the socket address of the application (`proxy_app`),
the listenting address of the tendermint peer (`p2p.laddr`),
and the listening address of the rpc server (`rpc.laddr`).
Some fields from the config file can be overwritten with flags.
## Broadcast API
Earlier, we used the `broadcast_tx_commit` endpoint to send a transaction.
When a transaction is sent to a tendermint node,
it will run via `CheckTx` against the application.
If it passes `CheckTx`, it will be included in the mempool,
broadcast to other peers, and eventually included in a block.
Since there are multiple phases to processing a transaction, we offer multiple endpoints to broadcast a transaction:
```
/broadcast_tx_async
/broadcast_tx_sync
/broadcast_tx_commit
```
These correspond to no-processing, processing through the mempool, and processing through a block, respectively.
That is, `broadcast_tx_async`, will return right away without waiting to hear if the transaction is even valid,
while `broadcast_tx_sync` will return with the result of running the transaction through `CheckTx`.
Using `broadcast_tx_commit` will wait until the transaction is committed in a block or until some timeout is reached,
but will return right away if the transaction does not pass `CheckTx`.
The return value for `broadcast_tx_commit` includes two fields, `check_tx` and `deliver_tx`, pertaining to the result of running
the transaction through those ABCI messages.
The benefit of using `broadcast_tx_commit` is that the request returns after the transaction is committed (ie. included in a block), but that can take on the order of a second. For a quick result, use `broadcast_tx_sync`,
but the transaction will not be committed until later, and by that point its effect on the state may change.
## Tendermint Networks
When `tendermint init` is run, both a `genesis.json` and `priv_validator.json` are created in `~/.tendermint`.
The `genesis.json` might look like:
```
{
"app_hash": "",
"chain_id": "test-chain-HZw6TB",
"genesis_time": "0001-01-01T00:00:00.000Z",
"validators": [
{
"amount": 10,
"name": "",
"pub_key": [
1,
"5770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
]
}
]
}
```
And the `priv_validator.json`:
```
{
"address": "4F4D895F882A18E1D1FC608D102601DA8D3570E5",
"last_height": 0,
"last_round": 0,
"last_signature": null,
"last_signbytes": "",
"last_step": 0,
"priv_key": [
1,
"F9FA3CD435BDAE54D0BCA8F1BC289D718C23D855C6DB21E8543F5E4F457E62805770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
],
"pub_key": [
1,
"5770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
]
}
```
The `priv_validator.json` actually contains a private key, and should thus be kept absolutely secret;
for now we work with the plain text.
Note the `last_` fields, which are used to prevent us from signing conflicting messages.
Note also that the `pub_key` (the public key) in the `priv_validator.json` is also present in the `genesis.json`.
The genesis file contains the list of public keys which may participate in the consensus,
and their corresponding voting power.
Greater than 2/3 of the voting power must be active (ie. the corresponding private keys must be producing signatures)
for the consensus to make progress.
In our case, the genesis file contains the public key of our `priv_validator.json`,
so a tendermint node started with the default root directory will be able to make new blocks,
as we've already seen.
If we want to add more nodes to the network, we have two choices:
we can add a new validator node, who will also participate in the consensus
by proposing blocks and voting on them,
or we can add a new non-validator node, who will not participate directly,
but will verify and keep up with the consensus protocol.
### Peers
To connect to peers on start-up, specify them in the `config.toml` or on the command line.
For instance,
```
tendermint node --p2p.seeds "1.2.3.4:46656,5.6.7.8:46656"
```
Alternatively, you can use the `/dial_seeds` endpoint of the RPC to specify peers for a running node to connect to:
```
curl --data-urlencode "seeds=[\"1.2.3.4:46656\",\"5.6.7.8:46656\"]" localhost:46657/dial_seeds
```
Additionally, the peer-exchange protocol can be enabled using the `--pex` flag,
though this feature is [still under development](https://github.com/tendermint/tendermint/issues/598)
If `--pex` is enabled, peers will gossip about known peers and form a more resilient network.
### Adding a Non-Validator
Adding a non-validator is simple. Just copy the original `genesis.json` to `~/.tendermint` on the new machine
and start the node, specifying seeds as necessary.
If no seeds are specified, the node won't make any blocks, because it's not a validator,
and it won't hear about any blocks, because it's not connected to the other peer.
### Adding a Validator
The easiest way to add new validators is to do it in the `genesis.json`, before starting the network.
For instance, we could make a new `priv_validator.json`, and copy it's `pub_key` into the above genesis.
We can generate a new `priv_validator.json` with the command:
```
tendermint gen_validator
```
Now we can update our genesis file. For instance, if the new `priv_validator.json` looks like:
```
{
"address": "AC379688105901436A34A65F185C115B8BB277A1",
"last_height": 0,
"last_round": 0,
"last_signature": null,
"last_signbytes": "",
"last_step": 0,
"priv_key": [
1,
"0D2ED337D748ADF79BE28559B9E59EBE1ABBA0BAFE6D65FCB9797985329B950C8F2B5AACAACC9FCE41881349743B0CFDE190DF0177744568D4E82A18F0B7DF94"
],
"pub_key": [
1,
"8F2B5AACAACC9FCE41881349743B0CFDE190DF0177744568D4E82A18F0B7DF94"
]
}
```
then the new `genesis.json` will be:
```
{
"app_hash": "",
"chain_id": "test-chain-HZw6TB",
"genesis_time": "0001-01-01T00:00:00.000Z",
"validators": [
{
"amount": 10,
"name": "",
"pub_key": [
1,
"5770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
]
},
{
"amount": 10,
"name": "",
"pub_key": [
1,
"8F2B5AACAACC9FCE41881349743B0CFDE190DF0177744568D4E82A18F0B7DF94"
]
}
]
}
```
Update the `genesis.json` in `~/.tendermint`. Copy the genesis file and the new `priv_validator.json`
to the `~/.tendermint` on a new machine.
Now run `tendermint node` on both machines, and use either `--p2p.seeds` or the `/dial_seeds` to get them to peer up.
They should start making blocks, and will only continue to do so as long as both of them are online.
To make a Tendermint network that can tolerate one of the validators failing, you need at least four validator nodes (> 2/3).
Updating validators in a live network is supported but must be explicitly programmed by the application developer.
See the [application developers guide](/docs/guides/app-development#Handshake) for more details.
### Local Network
To run a network locally, say on a single machine, you must change the `_laddr` fields in the `config.toml` (or using the flags)
so that the listening addresses of the various sockets don't conflict.
Additionally, you must set `addrbook_strict=false` in the `config.toml`,
otherwise Tendermint's p2p library will deny making connections to peers with the same IP address.
## More
Got a couple nodes talking to each other using the dummy app?
Try a more sophisticated app like [Ethermint](https://github.com/tendermint/ethermint),
or learn more about building your own in the [Application Developer's Guide](/docs/guides/app-development).

5
docs/index.rst
View File

@ -27,3 +27,8 @@ See our [Community](/community) page for more ways to collaborate.
You can also [get in touch with the team](/contact).
Most importantly, enjoy!
Next Steps
----------

113
docs/install-from-source.rst Normal file
View File

@ -0,0 +1,113 @@
Install from Source
===================
This page provides instructions on installing Tendermint from source. To
download pre-built binaries, see the `Download page </download>`__.
Install Go
----------
Make sure you have `installed Go <https://golang.org/doc/install>`__ and
set the ``GOPATH``.
Install Tendermint
------------------
You should be able to install the latest with a simple
::
go get github.com/tendermint/tendermint/cmd/tendermint
Run ``tendermint --help`` for more.
If the installation failed, a dependency may been updated and become
incompatible with the latest Tendermint master branch. We solve this
using the ``glide`` tool for dependency management.
Fist, install ``glide``:
::
go get github.com/Masterminds/glide
Now we can fetch the correct versions of each dependency by running:
::
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint
Note that even though ``go get`` originally failed, the repository was
still cloned to the correct location in the ``$GOPATH``.
The latest Tendermint Core version is now installed.
Reinstall
~~~~~~~~~
If you already have Tendermint installed, and you make updates, simply
::
cd $GOPATH/src/github.com/tendermint/tendermint
go install ./cmd/tendermint
To upgrade, there are a few options:
- set a new ``$GOPATH`` and run
``go get github.com/tendermint/tendermint/cmd/tendermint``. This
makes a fresh copy of everything for the new version.
- run ``go get -u github.com/tendermint/tendermint/cmd/tendermint``,
where the ``-u`` fetches the latest updates for the repository and
its dependencies
- fetch and checkout the latest master branch in
``$GOPATH/src/github.com/tendermint/tendermint``, and then run
``glide install && go install ./cmd/tendermint`` as above.
Note the first two options should usually work, but may fail. If they
do, use ``glide``, as above:
::
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint
Since the third option just uses ``glide`` right away, it should always
work.
Troubleshooting
~~~~~~~~~~~~~~~
If ``go get`` failing bothers you, fetch the code using ``git``:
::
mkdir -p $GOPATH/src/github.com/tendermint
git clone https://github.com/tendermint/tendermint $GOPATH/src/github.com/tendermint/tendermint
cd $GOPATH/src/github.com/tendermint/tendermint
glide install
go install ./cmd/tendermint
Run
~~~
To start a one-node blockchain with a simple in-process application:
::
tendermint init
tendermint node --proxy_app=dummy
See the `App Development </docs/guides/app-development>`__ guide for
more details on building applications, and the `Using
Tendermint </docs/guides/using-tendermint>`__ guide for more details
about using the ``tendermint`` program.
Next Step
---------
Learn how to `create your first ABCI
app </docs/getting-started/first-abci-app>`__.

365
docs/using-tendermint.rst Normal file
View File

@ -0,0 +1,365 @@
Using Tendermint
================
This is a guide to using the ``tendermint`` program from the command
line. It assumes only that you `have tendermint installed </download>`__
and have some rudimentary idea of what Tendermint and ABCI are.
You can see the help menu with ``tendermint --help``, and the version
number with ``tendermint version``.
Directory Root
--------------
The default directory for blockchain data is ``~/.tendermint``. Override
this by setting the ``TMROOT`` environment variable.
Initialize
----------
Initialize the root directory by running:
::
tendermint init
This will create a new private key (``priv_validator.json``), and a
genesis file (``genesis.json``) containing the associated public key.
This is all that's necessary to run a local testnet with one validator.
For more elaborate initialization, see our `testnet deployment
tool <https://github.com/tendermint/tools/tree/master/mintnet-kubernetes>`__.
Run
---
To run a tendermint node, use
::
tendermint node
By default, Tendermint will try to connect to a abci appliction on
`127.0.0.1:46658 <127.0.0.1:46658>`__. If you have the ``dummy`` ABCI
app installed, run it in another window. If you don't, kill tendermint
and run an in-process version with
::
tendermint node --proxy_app=dummy
After a few seconds you should see blocks start streaming in. Note that
blocks are produced regularly, even if there are no transactions. This
changes `with this pull
request <https://github.com/tendermint/tendermint/pull/584>`__.
Tendermint supports in-process versions of the dummy, counter, and nil
apps that ship as examples in the `ABCI
repository <https://github.com/tendermint/abci>`__. It's easy to compile
your own app in-process with tendermint if it's written in Go. If your
app is not written in Go, simply run it in another process, and use the
``--proxy_app`` flag to specify the address of the socket it is
listening on, for instance
::
tendermint node --proxy_app=/var/run/abci.sock
Transactions
------------
To send a transaction, use ``curl`` to make requests to the Tendermint
RPC server:
::
curl http://localhost:46657/broadcast_tx_commit?tx=\"abcd\"
For handling responses, we recommend you `install the jsonpp
tool <http://jmhodges.github.io/jsonpp/>`__ to pretty print the JSON.
We can see the chain's status at the ``/status`` end-point:
::
curl http://localhost:46657/status | jsonpp
and the ``latest_app_hash`` in particular:
::
curl http://localhost:46657/status | jsonpp | grep app_hash
Visit http://localhost:46657 in your browser to see the list of other
endpoints. Some take no arguments (like ``/status``), while others
specify the argument name and use ``_`` as a placeholder.
Reset
-----
**WARNING: UNSAFE** Only do this in development and only if you can
afford to lose all blockchain data!
To reset a blockchain, stop the node, remove the ``~/.tendermint/data``
directory and run
::
tendermint unsafe_reset_priv_validator
This final step is necessary to reset the ``priv_validator.json``, which
otherwise prevents you from making conflicting votes in the consensus
(something that could get you in trouble if you do it on a real
blockchain). If you don't reset the ``priv_validator.json``, your fresh
new blockchain will not make any blocks.
Configuration
-------------
Tendermint uses a ``config.toml`` for configutation. For details, see
`the documentation </docs/specs/configuration>`__.
Notable options include the socket address of the application
(``proxy_app``), the listenting address of the tendermint peer
(``p2p.laddr``), and the listening address of the rpc server
(``rpc.laddr``).
Some fields from the config file can be overwritten with flags.
Broadcast API
-------------
Earlier, we used the ``broadcast_tx_commit`` endpoint to send a
transaction. When a transaction is sent to a tendermint node, it will
run via ``CheckTx`` against the application. If it passes ``CheckTx``,
it will be included in the mempool, broadcast to other peers, and
eventually included in a block.
Since there are multiple phases to processing a transaction, we offer
multiple endpoints to broadcast a transaction:
::
/broadcast_tx_async
/broadcast_tx_sync
/broadcast_tx_commit
These correspond to no-processing, processing through the mempool, and
processing through a block, respectively. That is,
``broadcast_tx_async``, will return right away without waiting to hear
if the transaction is even valid, while ``broadcast_tx_sync`` will
return with the result of running the transaction through ``CheckTx``.
Using ``broadcast_tx_commit`` will wait until the transaction is
committed in a block or until some timeout is reached, but will return
right away if the transaction does not pass ``CheckTx``. The return
value for ``broadcast_tx_commit`` includes two fields, ``check_tx`` and
``deliver_tx``, pertaining to the result of running the transaction
through those ABCI messages.
The benefit of using ``broadcast_tx_commit`` is that the request returns
after the transaction is committed (ie. included in a block), but that
can take on the order of a second. For a quick result, use
``broadcast_tx_sync``, but the transaction will not be committed until
later, and by that point its effect on the state may change.
Tendermint Networks
-------------------
When ``tendermint init`` is run, both a ``genesis.json`` and
``priv_validator.json`` are created in ``~/.tendermint``. The
``genesis.json`` might look like:
::
{
"app_hash": "",
"chain_id": "test-chain-HZw6TB",
"genesis_time": "0001-01-01T00:00:00.000Z",
"validators": [
{
"amount": 10,
"name": "",
"pub_key": [
1,
"5770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
]
}
]
}
And the ``priv_validator.json``:
::
{
"address": "4F4D895F882A18E1D1FC608D102601DA8D3570E5",
"last_height": 0,
"last_round": 0,
"last_signature": null,
"last_signbytes": "",
"last_step": 0,
"priv_key": [
1,
"F9FA3CD435BDAE54D0BCA8F1BC289D718C23D855C6DB21E8543F5E4F457E62805770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
],
"pub_key": [
1,
"5770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
]
}
The ``priv_validator.json`` actually contains a private key, and should
thus be kept absolutely secret; for now we work with the plain text.
Note the ``last_`` fields, which are used to prevent us from signing
conflicting messages.
Note also that the ``pub_key`` (the public key) in the
``priv_validator.json`` is also present in the ``genesis.json``.
The genesis file contains the list of public keys which may participate
in the consensus, and their corresponding voting power. Greater than 2/3
of the voting power must be active (ie. the corresponding private keys
must be producing signatures) for the consensus to make progress. In our
case, the genesis file contains the public key of our
``priv_validator.json``, so a tendermint node started with the default
root directory will be able to make new blocks, as we've already seen.
If we want to add more nodes to the network, we have two choices: we can
add a new validator node, who will also participate in the consensus by
proposing blocks and voting on them, or we can add a new non-validator
node, who will not participate directly, but will verify and keep up
with the consensus protocol.
Peers
~~~~~
To connect to peers on start-up, specify them in the ``config.toml`` or
on the command line.
For instance,
::
tendermint node --p2p.seeds "1.2.3.4:46656,5.6.7.8:46656"
Alternatively, you can use the ``/dial_seeds`` endpoint of the RPC to
specify peers for a running node to connect to:
::
curl --data-urlencode "seeds=[\"1.2.3.4:46656\",\"5.6.7.8:46656\"]" localhost:46657/dial_seeds
Additionally, the peer-exchange protocol can be enabled using the
``--pex`` flag, though this feature is `still under
development <https://github.com/tendermint/tendermint/issues/598>`__ If
``--pex`` is enabled, peers will gossip about known peers and form a
more resilient network.
Adding a Non-Validator
~~~~~~~~~~~~~~~~~~~~~~
Adding a non-validator is simple. Just copy the original
``genesis.json`` to ``~/.tendermint`` on the new machine and start the
node, specifying seeds as necessary. If no seeds are specified, the node
won't make any blocks, because it's not a validator, and it won't hear
about any blocks, because it's not connected to the other peer.
Adding a Validator
~~~~~~~~~~~~~~~~~~
The easiest way to add new validators is to do it in the
``genesis.json``, before starting the network. For instance, we could
make a new ``priv_validator.json``, and copy it's ``pub_key`` into the
above genesis.
We can generate a new ``priv_validator.json`` with the command:
::
tendermint gen_validator
Now we can update our genesis file. For instance, if the new
``priv_validator.json`` looks like:
::
{
"address": "AC379688105901436A34A65F185C115B8BB277A1",
"last_height": 0,
"last_round": 0,
"last_signature": null,
"last_signbytes": "",
"last_step": 0,
"priv_key": [
1,
"0D2ED337D748ADF79BE28559B9E59EBE1ABBA0BAFE6D65FCB9797985329B950C8F2B5AACAACC9FCE41881349743B0CFDE190DF0177744568D4E82A18F0B7DF94"
],
"pub_key": [
1,
"8F2B5AACAACC9FCE41881349743B0CFDE190DF0177744568D4E82A18F0B7DF94"
]
}
then the new ``genesis.json`` will be:
::
{
"app_hash": "",
"chain_id": "test-chain-HZw6TB",
"genesis_time": "0001-01-01T00:00:00.000Z",
"validators": [
{
"amount": 10,
"name": "",
"pub_key": [
1,
"5770B4DD55B3E08B7F5711C48B516347D8C33F47C30C226315D21AA64E0DFF2E"
]
},
{
"amount": 10,
"name": "",
"pub_key": [
1,
"8F2B5AACAACC9FCE41881349743B0CFDE190DF0177744568D4E82A18F0B7DF94"
]
}
]
}
Update the ``genesis.json`` in ``~/.tendermint``. Copy the genesis file
and the new ``priv_validator.json`` to the ``~/.tendermint`` on a new
machine.
Now run ``tendermint node`` on both machines, and use either
``--p2p.seeds`` or the ``/dial_seeds`` to get them to peer up. They
should start making blocks, and will only continue to do so as long as
both of them are online.
To make a Tendermint network that can tolerate one of the validators
failing, you need at least four validator nodes (> 2/3).
Updating validators in a live network is supported but must be
explicitly programmed by the application developer. See the `application
developers guide </docs/guides/app-development#Handshake>`__ for more
details.
Local Network
~~~~~~~~~~~~~
To run a network locally, say on a single machine, you must change the
``_laddr`` fields in the ``config.toml`` (or using the flags) so that
the listening addresses of the various sockets don't conflict.
Additionally, you must set ``addrbook_strict=false`` in the
``config.toml``, otherwise Tendermint's p2p library will deny making
connections to peers with the same IP address.
More
----
Got a couple nodes talking to each other using the dummy app? Try a more
sophisticated app like
`Ethermint <https://github.com/tendermint/ethermint>`__, or learn more
about building your own in the `Application Developer's
Guide </docs/guides/app-development>`__.