feat: wait for bitcoind to accept RPC calls

readme.md

@@ -66,10 +66,11 @@ docker pull ghcr.io/joinmarket-webui/jam-standalone:latest
 The following environment variables control the configuration
 - `APP_USER` (optional; username used for basic authentication)
 - `APP_PASSWORD` (optional, but required if `APP_USER` is provided; password used for basic authentication)
-- `ENSURE_WALLET` (optional; create and load the wallet in bitcoin core on startup)
+- `ENSURE_WALLET` (optional, defaults to `false`; create and load the wallet in bitcoin core on startup)
 - `READY_FILE` (optional; wait for a file to be created before starting all services, e.g. to wait for chain synchronization)
-- `REMOVE_LOCK_FILES` (optional; remove leftover lockfiles from possible unclean shutdowns on startup)
-- `RESTORE_DEFAULT_CONFIG` (optional; overwrites any existing `joinmarket.cfg` file the container's default config on startup)
+- `REMOVE_LOCK_FILES` (optional, defaults to `false`; remove leftover lockfiles from possible unclean shutdowns on startup)
+- `RESTORE_DEFAULT_CONFIG` (optional, defaults to `false`; overwrites any existing `joinmarket.cfg` file with a default config)
+- `WAIT_FOR_BITCOIND` (optional, defaults to `true`; wait for bitcoind to accept RPC request and report >= 100 blocks)
 
 Variables starting with prefix `JM_` will be applied to `joinmarket.cfg` e.g.:
 - `JM_GAPLIMIT: 2000` will set the `gaplimit` config value to `2000`
@@ -110,6 +111,7 @@ docker run --rm  -it \
         --env ENSURE_WALLET="true" \
         --env REMOVE_LOCK_FILES="true" \
         --env RESTORE_DEFAULT_CONFIG="true" \
+        --env WAIT_FOR_BITCOIND="true" \
         --volume jmdatadir:/root/.joinmarket \
         --publish "8080:80" \
         joinmarket-webui/jam-standalone

standalone/Dockerfile

@@ -95,7 +95,7 @@ RUN addgroup --system tor \
     && apt-get update \
     && apt-get install -qq --no-install-recommends --no-install-suggests -y \
     # image dependencies
-    tini iproute2 procps vim \
+    tini iproute2 procps vim jq \
     # servers dependencies (see `install.sh`)
     build-essential automake pkg-config libtool libltdl-dev python3-dev python3-setuptools python3-pip \
     # tor

standalone/jam-entrypoint.sh

@@ -75,15 +75,36 @@ done
 
 # wait for a ready file to be created if necessary
 if [ "${READY_FILE}" ] && [ "${READY_FILE}" != "false" ]; then
-    echo "Waiting for $READY_FILE to be created..."
+    echo "Waiting for file $READY_FILE to be created..."
     while [ ! -f "$READY_FILE" ]; do sleep 1; done
-    echo "The chain is fully synched"
+    echo "Successfully waited for file $READY_FILE to be created."
+fi
+
+btcuser="${jmenv['rpc_user']}:${jmenv['rpc_password']}"
+btchost="http://${jmenv['rpc_host']}:${jmenv['rpc_port']}"
+
+# wait for bitcoind to accept RPC requests if necessary
+if [ "${WAIT_FOR_BITCOIND}" != "false" ]; then
+    echo "Waiting for bitcoind to accept RPC requests..."
+    # use `getblockchaininfo` command here, as this is the first request JM is
+    # performing during initialization
+    getblockchaininfo_payload="{\
+        \"jsonrpc\":\"2.0\",\
+        \"id\":\"curl\",\
+        \"method\":\"getblockchaininfo\",\
+        \"params\":{}\
+    }"
+    # generally only testing for a non-error response would be enough, but 
+    # waiting for blocks >= 100 is needed for regtest environments as well!
+    until curl --silent --show-error --user "${btcuser}" --data-binary "${getblockchaininfo_payload}" "${btchost}" 2>&1 | jq -e ".result.blocks >= 100" > /dev/null 2>&1
+    do
+        sleep 5
+    done
+    echo "Successfully waited for bitcoind to accept RPC requests."
 fi
 
 # ensure that a wallet exists and is loaded if necessary
 if [ "${ENSURE_WALLET}" = "true" ]; then
-    btcuser="${jmenv['rpc_user']}:${jmenv['rpc_password']}"
-    btchost="http://${jmenv['rpc_host']}:${jmenv['rpc_port']}"
     wallet_name="${jmenv['rpc_wallet_file']}"
 
     echo "Creating wallet $wallet_name if missing..."