Container: Support ERL_DIST_PORT

.github/container/Dockerfile

@@ -113,7 +113,7 @@ HEALTHCHECK \
 WORKDIR $HOME
 USER ejabberd
 VOLUME ["$HOME/conf", "$HOME/database", "$HOME/logs", "$HOME/upload"]
-EXPOSE 1883 4369-4399 5222 5269 5280 5443
+EXPOSE 1883 4369-4399 5210 5222 5269 5280 5443
 
 ENTRYPOINT ["/usr/local/bin/ejabberdctl"]
 CMD ["foreground"]

.github/container/ejabberdctl.template

@@ -82,6 +82,7 @@ if [ -n "$INET_DIST_INTERFACE" ] ; then
         ERLANG_OPTS="$ERLANG_OPTS -kernel inet_dist_use_interface $INET_DIST_INTERFACE2"
     fi
 fi
+[ -n "$ERL_DIST_PORT" ] && ERLANG_OPTS="$ERLANG_OPTS -erl_epmd_port $ERL_DIST_PORT -start_epmd false"
 # if vm.args file exists in config directory, pass it to Erlang VM
 [ -f "$VMARGS" ] && ERLANG_OPTS="$ERLANG_OPTS -args_file $VMARGS"
 ERL_LIBS='{{libdir}}'
@@ -103,6 +104,7 @@ export EJABBERD_LOG_PATH
 export EJABBERD_PID_PATH
 export ERL_CRASH_DUMP
 export ERL_EPMD_ADDRESS
+export ERL_DIST_PORT
 export ERL_INETRC
 export ERL_MAX_PORTS
 export ERL_MAX_ETS_TABLES
@@ -111,6 +113,11 @@ export CONTRIB_MODULES_CONF_DIR
 export ERL_LIBS
 export SCRIPT_DIR
 
+set_dist_client()
+{
+    [ -n "$ERL_DIST_PORT" ] && ERLANG_OPTS="$ERLANG_OPTS -dist_listen false"
+}
+
 # run command either directly or via su $INSTALLUSER
 run_cmd()
 {
@@ -233,6 +240,7 @@ uid()
 # stop epmd if there is no other running node
 stop_epmd()
 {
+    [ -n "$ERL_DIST_PORT" ] && return
     "$EPMD" -names 2>/dev/null | grep -q name || "$EPMD" -kill >/dev/null
 }
 
@@ -240,6 +248,7 @@ stop_epmd()
 # if all ok, ensure runtime directory exists and make it current directory
 check_start()
 {
+    [ -n "$ERL_DIST_PORT" ] && return
     "$EPMD" -names 2>/dev/null | grep -q " ${ERLANG_NODE%@*} " && {
         pgrep -f "$ERLANG_NODE" >/dev/null && {
             echo "ERROR: The ejabberd node '$ERLANG_NODE' is already running."
@@ -328,14 +337,17 @@ case $1 in
         ;;
     debug)
         debugwarning
+        set_dist_client
         exec_erl "$(uid debug)" -hidden -remsh "$ERLANG_NODE"
         ;;
     etop)
+        set_dist_client
         exec_erl "$(uid top)" -hidden -node "$ERLANG_NODE" -s etop \
                  -s erlang halt -output text
         ;;
     iexdebug)
         debugwarning
+        set_dist_client
         exec_iex "$(uid debug)" --remsh "$ERLANG_NODE"
         ;;
     iexlive)
@@ -345,20 +357,24 @@ case $1 in
     ping)
         PEER=${2:-$ERLANG_NODE}
         [ "$PEER" = "${PEER%.*}" ] && PS="-s"
+        set_dist_client
         exec_cmd "$ERL" ${PS:--}name "$(uid ping "$(hostname $PS)")" $ERLANG_OPTS \
                  -noinput -hidden -eval 'io:format("~p~n",[net_adm:ping('"'$PEER'"')])' \
                  -s erlang halt -output text
         ;;
     started)
+        set_dist_client
         wait_status 0 30 2 # wait 30x2s before timeout
         ;;
     stopped)
+        set_dist_client
         wait_status 3 30 2 && stop_epmd # wait 30x2s before timeout
         ;;
     post_waiter)
         post_waiter_waiting
         ;;
     *)
+        set_dist_client
         run_erl "$(uid ctl)" -hidden -noinput -s ejabberd_ctl \
                  -extra "$ERLANG_NODE" $NO_TIMEOUT "$@"
         result=$?

CONTAINER.md

@@ -179,6 +179,7 @@ This container image exposes the ports:
 - `5443`: With encryption, used for admin interface, API, CAPTCHA, OAuth, Websockets and XMPP BOSH.
 - `1883`: Used for MQTT
 - `4369-4399`: EPMD and Erlang connectivity, used for `ejabberdctl` and clustering
+- `5210`: Erlang connectivity when `ERL_DIST_PORT` is set, alternative to EPMD
 
 
 ### Volumes
@@ -233,6 +234,23 @@ For this you can either:
 - edit `conf/ejabberdctl.cfg` and set variables `ERLANG_NODE` and `ERLANG_COOKIE`
 - set the environment variables `ERLANG_NODE_ARG` and `ERLANG_COOKIE`
 
+Example to connect a local `ejabberdctl` to a containerized ejabberd:
+1. When creating the container, export port 5210, and set `ERLANG_COOKIE`:
+```
+docker run --name ejabberd -it \
+  -e ERLANG_COOKIE=`cat $HOME/.erlang.cookie` \
+  -p 5210:5210 -p 5222:5222 \
+  ghcr.io/processone/ejabberd
+```
+2. Set `ERL_DIST_PORT=5210` in ejabberdctl.cfg of container and local ejabberd
+3. Restart the container
+4. Now use `ejabberdctl` in your local ejabberd deployment
+
+To connect using a local `ejabberd` script:
+```
+ERL_DIST_PORT=5210 _build/dev/rel/ejabberd/bin/ejabberd ping
+```
+
 Example using environment variables (see full example [docker-compose.yml](https://github.com/processone/docker-ejabberd/issues/64#issuecomment-887741332)):
 ```yaml
     environment: