Expose ZMQ block notifications toggle in config

New 'zmq-enabled' boolean (default true) makes the entrypoint
export BITCOIN_ZMQ_BLOCK=tcp://<bitcoind-host>:28332, which
kamado-api's zmqmon subscribes to for sub-second chain refresh
on the dashboard. Disable it if your bitcoind doesn't have
zmqpubhashblock exposed.

docker_entrypoint.sh

@@ -42,10 +42,13 @@ export MINDIFF=$(q '.mindiff // 1000')
 export MAXDIFF=$(q '.maxdiff // 0')
 export DROPIDLE=$(q '.dropidle // 0')
 LOG_LEVEL=$(q '.log-level // "info"')
+ZMQ_ENABLED=$(q '.zmq-enabled // true')
 
 export LOGDIR=/var/log/ckpool
 export SOCKET_DIR=/run/ckpool
 export BITCOIN_NOTIFY=true
+# ckpool itself doesn't use ZMQ in this build — zmqblock is stripped
+# from the rendered conf below. kamado-api subscribes separately.
 export ZMQ_BLOCK=""
 export BLOCKPOLL_MS=100
 export UPDATE_INTERVAL_S=30
@@ -86,6 +89,11 @@ export CKPOOL_LOGFILE="${LOGDIR}/ckpool.log"
 export BITCOIN_RPC_URL="http://${BITCOIN_RPC_HOST}:${BITCOIN_RPC_PORT}"
 export POLL_INTERVAL=5s
 export KAMADO_LOG_LEVEL="${LOG_LEVEL}"
+if [[ "${ZMQ_ENABLED}" == "true" ]]; then
+    export BITCOIN_ZMQ_BLOCK="tcp://${BITCOIN_RPC_HOST}:28332"
+else
+    export BITCOIN_ZMQ_BLOCK=""
+fi
 
 echo "kamado-entrypoint: starting kamado-api"
 /usr/local/bin/kamado-api &