Merge pull request #366 from zcash/sasha-doc-updates

Improve documentation for use with docker-compose

docs/docker-compose-setup.md

@@ -16,10 +16,11 @@ Copy `.env.example` to `.env` and change any required paramaters.
 | ------------- |:-------------:|
 |   `GF_SECURITY_ADMIN_USER`   |    Grafana admin user name   |
 |   `ZCASHD_RPCUSER`   |    zcashd rpc user   |
+|   `ZCASHD_RPCPASSWORD` | zcashd rpc password |
 |   `ZCASHD_RPCPORT`   |    zcashd rpc port   |
-|`ZCASHD_ALLOWIP`| zcashd rpc allowed IPs (don't |change unless you know what you're doing)|
+|`ZCASHD_ALLOWIP`| zcashd rpc allowed IPs (don't change unless you know what you're doing)|
-|`ZCASHD_DATADIR`| local location of zcasd data directory. `uid` 2001 needs write access|
+|`ZCASHD_DATADIR`| local location of zcashd data directory. `uid` 2001 needs write access|
-|`ZCASHD_PARMDIR`| local location of zcasd data directory. `uid` 2001 needs read access|
+|`ZCASHD_PARMDIR`| local location of zcashd data directory. `uid` 2001 needs read access|
 |`ZCASHD_NETWORK`| zcashd network to use, `testnet` or `mainnet`|
 |`ZCASHD_GEN`| should zcashd mine? `0` or `1`
 |`LWD_PORT`| port for lightwalletd to bind to|
@@ -32,6 +33,28 @@ Copy `.env.example` to `.env` and change any required paramaters.
 ./buildenv.sh | tee .env
 ```
 
+## Edit the two zcash.conf files
+There are two zcash.conf files; one read by zcashd, one read by lightwalletd.
+
+### `$ZCASHD_DATADIR/zcash.conf`—read by zcashd
+The zcashd's `zcash.conf` needs to look like: 
+```
+rpcuser=zcashrpc
+rpcpassword=TODO INSERT A RANDOM PASSWORD HERE
+experimentalfeatures=1
+lightwalletd=1
+```
+
+Replace `TODO INSERT A RANDOM PASSWORD HERE` with a random password, e.g. the output of `head -c 16 /dev/urandom | base64`.
+
+`rpcuser` and `rpcpassword` must be set, as lightwalletd doesn't work with RPC cookies (see the [rpcpassword](https://zcash.readthedocs.io/en/latest/rtd_pages/zcash_conf_guide.html) documentation) for authentication.
+
+`rpcuser` and `rpcpassword` in `.env` are only used by zcashd_exporter, but they also must be the same values as in `$ZCASHD_DATADIR/zcash.conf`
+
+### `lightwalletd/docker/zcash.conf`—read by lightwalletd
+The other `zcashd.conf`—the one read by lightwalletd—needs to have `rpcbind` (the address of the zcashd it will connect to) set to `zcashd`, and then docker-compose networking will make it resolve to the right IP address. Also, it needs to have the same `rpcuser` and `rpcpassword` values that are listed in `$ZCASHD_DATADIR/zcash.conf` to be able to authenticate.
+
+
 ## Build initial local docker image
 
 `docker-compose build`
@@ -98,3 +121,18 @@ Loki as a rich query syntax to help with log in many ways, for example combine 2
 ![grafana-explore4](./images/grafana-explore-4.png)
 
 See more here: https://github.com/grafana/loki/blob/master/docs/logql.md
+
+
+# Exposing `lightwalletd` to the network
+
+Edit `docker-compose.yml` to look like
+
+```
+    ports:    
+      #- "127.0.0.1:$LWD_GRPC_PORT:$LWD_GRPC_PORT"
+      #- "127.0.0.1:$LWD_HTTP_PORT:$LWD_HTTP_PORT"           
+      - "0.0.0.0:$LWD_GRPC_PORT:$LWD_GRPC_PORT"
+      - "0.0.0.0:$LWD_HTTP_PORT:$LWD_HTTP_PORT"      
+```
+
+When you edit these lines in `docker-compose.yml`, stopping/starting the individual `lightwalletd` container doesn't actually make the changes happen—you have to stop/start the whole `docker-compose` ensemble of containers because the ports/network config stuff lives at that level and doesn't seem to be affected by individual container stop/starts. Also if you want to expose `lightwalletd` to the whole internet, you don't need to specify an IP address, `0.0.0.0` works as it should.