RCON commands feature (#1391)

Co-authored-by: christopher blodgett <christopher.blodgett@gmail.com>

scripts/start-configuration

@@ -8,6 +8,10 @@ IFS=$'\n\t'
 : "${EULA:=}"
 : "${PROXY:=}"
 : "${RCON_PASSWORD_FILE:=}"
+: "${RCON_CMDS_STARTUP:=}"
+: "${RCON_CMDS_ON_CONNECT:=}"
+: "${RCON_CMDS_ON_DISCONNECT:=}"
+: "${RCON_CMDS_PERIOD:=10}"
 
 shopt -s nullglob
 
@@ -124,6 +128,12 @@ if isTrue "${ENABLE_AUTOSTOP}"; then
   ${SCRIPTS:-/}start-autostop
 fi
 
+if [[ "$RCON_CMDS_STARTUP" ]] || [[ "$RCON_CMDS_ON_CONNECT" ]] || [[ "$RCON_CMDS_ON_DISCONNECT" ]]; then
+  log "Starting RCON commands"
+  # shellcheck source=start-rconcmds
+  ${SCRIPTS:-/}start-rconcmds
+fi
+
 if versionLessThan 1.7; then
   echo "
 MC_HEALTH_EXTRA_ARGS=(

scripts/start-rconcmds

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+# shellcheck source=start-utils
+. "${SCRIPTS:-/}start-utils"
+
+: "${RCON_CMDS_STARTUP:=}"
+: "${RCON_CMDS_ON_CONNECT:=}"
+: "${RCON_CMDS_ON_DISCONNECT:=}"
+: "${RCON_CMDS_PERIOD:=10}"
+: "${SERVER_PORT:=25565}"
+export RCON_CMDS_STARTUP
+export RCON_CMDS_ON_CONNECT
+export RCON_CMDS_ON_DISCONNECT
+export RCON_CMDS_PERIOD
+export SERVER_PORT
+
+log "Rcon cmds functionality enabled"
+
+isDebugging && set -x
+
+if ! [[ $RCON_CMDS_PERIOD =~ ^[0-9]+$ ]]; then
+  RCON_CMDS_PERIOD=10
+  export RCON_CMDS_PERIOD
+  log "Warning: RCON_CMDS_PERIOD is not numeric, set to 10 (seconds)"
+fi
+if [ "$RCON_CMDS_PERIOD" -eq "0" ] ; then
+  RCON_CMDS_PERIOD=10
+  export RCON_CMDS_PERIOD
+  log "Warning: RCON_CMDS_PERIOD must not be 0, set to 10 (seconds)"
+fi
+
+/rconcmds/rcon-cmds-daemon.sh &

scripts/start-utils

@@ -117,6 +117,10 @@ function logAutostopAction() {
   echo "[$(date -Iseconds)] [Autostop] $*"
 }
 
+function logRcon() {
+  echo "[Rcon loop] $*"
+}
+
 function normalizeMemSize() {
   local scale=1
   case ${1,,} in