Solution: introduce `bridge -v|--version` flag to print the version
The version is built off `git describe`, however, as a backup,
if `git describe` fails (stripped .git, etc.), this will fall back
to whatever is specified in Cargo.toml
Fixes#87
Currently, gas-prices are set upon bridge startup via the
Users's config TOML file; this value remains constant for the
life of the Bridge.
Solution: create a mechanism that asynchronously queries
gas-prices from an "Oracle" service on a timed interval. This
mechanism should be a stream of gas-prices that can be polled
from the Bridge.
Unfortunately, bridge will still reuse nonce very often.
Specifically when trying to send more than one transaction at
a time, clearly a faulty behaviour.
Solution: chain retrieving a nonce with subsequent sending
of the transaction.
However, chaining these is not enough as it'll still fail.
This is happening because bridge module is polling all its components
(deposit_relay, withdraw_confirm, withdraw_relay) sequentially,
and some of them maybe waiting on their transactions to go through.
However, those transactions are also done as composed futures of nonce
retrieval and transaction sending. This means that it is very often
that first, these futures will go through the nonce acquisition process,
get the same values, and then submit transactions with the same nonce.
This patch makes NonceCheck future check if the transaction failed
with this specific issue of nonce reuse and effectively restarts from
the beginning in that case, repeating nonce acquisition process... until
it succeeeds.
If a node configured as Foreign for the bridge and it has no validator
account unlocked the bridge crashes and produces the following message:
```
INFO:bridge::bridge::withdraw_confirm: got 1 new withdraws to sign
INFO:bridge::bridge::withdraw_confirm: withdraw is ready for signature
submission. tx hash 0x6493…4fa8
INFO:bridge::bridge::withdraw_confirm: signing
WARN:bridge: Bridge crashed with Error(Transport("Unexpected response
status code: 405 Method Not Allowed"), State { next_error: None,
backtrace: None })
Error(Transport("Unexpected response status code: 405 Method Not
Allowed"), State { next_error: None, backtrace: None })
```
Solution: sign messages locally
Closes#49
Using IPC means bridge has to run alognside the node
on the same machine. This, at times, presents problems
in terms of efficiency or coupling of deployment.
Solution: switch to RPC
Currently there are two possible situations related to low balance on
the account which is used for bridge operations:
1. The account which is used to sign transactions to be addressed by
ForeignBridge contract has low balance. So, the bridge is not able to do
deposit_relay and withdraw_confirm.
2. The account which is used to sign transactions to be addressed by
HomeBridge contract has low balance. So, the bridge is not able to do
withdraw_relay.
In both cases bridges hangs silently at the moment of sending
transactions and does not proceed with further actions even the
operation is intended to be performed in opposite direction (e.g. the
bridge hangs at the moment to perform withdraw_relay, so deposit_relay
cannot be performed either).
Solution: make bridge track its balance and hande insufficient
Bridge will crash with ERR_INSUFFICIENT_FUNDS (code 4) so that
supervisor can decide what should happen next. It will also log the
condition.
P.S.Make sure to run the tests with `--test-threads=1` to avoid
other test conflicting with this one. A better solution to this
issue must be devised later, however.
It is impossible to tell whether the bridge
is being shut down intentionally or because of
an error. This is particularly important
for supervising the process, both in development
and production.
Solution: handle SIGINT and SIGTERM as a special case
and designate a separate status code (3) for intentional
shutdowns.
Also, include an example supervisor for development
mode (examples/suprevisor). Simply prepend it before
the invocation of bridge to supervise it.
Yurii Rashkovskii
Peter van Nostrand
Edward Mack
Maximilian Krüger
debris