add shutdown if no players online capability

Author: rfvgyhn

Dockerfile

@@ -29,12 +29,15 @@ RUN apk update &&\
     apk add --no-cache procps tmux
 RUN ln -s ${HOME}/.local/share/Terraria/ /terraria
 COPY inject.sh /usr/local/bin/inject
+COPY handle-idle.sh /usr/local/bin/handle-idle
 
 EXPOSE 7777
 ENV TMOD_SHUTDOWN_MSG="Shutting down!"
 ENV TMOD_AUTOSAVE_INTERVAL="*/10 * * * *"
+ENV TMOD_IDLE_CHECK_INTERVAL=""
+ENV TMOD_IDLE_CHECK_OFFSET=0
 
 COPY config.txt entrypoint.sh ./
-RUN chmod +x entrypoint.sh /usr/local/bin/inject
+RUN chmod +x entrypoint.sh /usr/local/bin/inject /usr/local/bin/handle-idle
 
 ENTRYPOINT [ "/terraria-server/entrypoint.sh" ]

README.md

@@ -40,12 +40,13 @@ You can inject [commands] from the host machine though. For example, assuming yo
 
 # Environment Variables
 
-Name                   | Default Value  | |
------------------------|----------------|-
-TMOD_SHUTDOWN_MSG      | Shutting Down! | Message that appears when server is shutting down
-TMOD_AUTOSAVE_INTERVAL | */10 * * * *   | Cron expression that specifies how often to save the world. Default is every 10 minutes.
-
-    docker run -d --name tmod -e TMOD_SHUTDOWN_MSG="Goodbye" -e TMOD_AUTOSAVE_INTERVAL="*/15 * * * *" -p 7777:7777 -v /etc/localtime:/etc/localtime:ro rfvgyhn/tmodloader
+Name                     | Default Value  | |
+-------------------------|----------------|-
+TMOD_SHUTDOWN_MSG        | Shutting Down! | Message that appears when server is shutting down
+TMOD_AUTOSAVE_INTERVAL   | */10 * * * *   | Cron expression that specifies how often to save the world. Default is every 10 minutes.
+TMOD_IDLE_CHECK_INTERVAL | Disabled       | Cron expression that specifies how often to check if no players are online. If none are online, the server will save the world and exit. This can be useful if your server costs are based on CPU usage.
+TMOD_IDLE_CHECK_OFFSET   | 0              | This allows for sub-second resolution if the idle check interval is specified
+    docker run -d --name tmod -e TMOD_SHUTDOWN_MSG="Goodbye" -e TMOD_AUTOSAVE_INTERVAL="*/15 * * * *" -e TMOD_IDLE_CHECK_INTERVAL="*/1 * * * *" -e TMOD_IDLE_CHECK_OFFSET=10 -p 7777:7777 -v /etc/localtime:/etc/localtime:ro rfvgyhn/tmodloader
 
 # Sample Docker Compose
 

entrypoint.sh

@@ -1,11 +1,11 @@
 #!/bin/sh
 
 pipe=/tmp/tmod.out
+players=/tmp/tmod.players.out
 
 function shutdown() {
   [ -n "$TMOD_SHUTDOWN_MSG" ] && inject "say $TMOD_SHUTDOWN_MSG"
   inject "exit"
-  
   tmuxPid=$(pgrep tmux)
   tmodPid=$(pgrep --parent $tmuxPid Main)
   while [ -e /proc/$tmodPid ]; do
@@ -22,13 +22,17 @@ else
   trap shutdown SIGTERM SIGINT
 
   saveMsg='Autosave - $(date +"%Y-%m-%d %T")'
+  idleMsg='Idle Check - $(date +"%Y-%m-%d %T")'
 
-  if ! crontab -l | grep -q "Autosave"; then
+  if [ ! -z "$TMOD_AUTOSAVE_INTERVAL" ] && ! crontab -l | grep -q "Autosave"; then
     (crontab -l 2>/dev/null; echo "$TMOD_AUTOSAVE_INTERVAL echo \"$saveMsg\" > $pipe && inject save") | crontab -
   fi
+  if [ ! -z "$TMOD_IDLE_CHECK_INTERVAL" ] && ! crontab -l | grep -q "Idle Check"; then
+    (crontab -l 2>/dev/null; echo "$TMOD_IDLE_CHECK_INTERVAL echo \"$idleMsg\" > $pipe && handle-idle $players") | crontab -
+  fi
   mkfifo $pipe
-  tmux new-session -d "$server -config config.txt > $pipe" &
-  /usr/sbin/crond -d 8
+  tmux new-session -d "$server -config config.txt | tee $pipe $players" &
+  sleep 60 && /usr/sbin/crond -d 8 &
   cat $pipe &
 
   wait ${!}

handle-idle.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+players="$1"
+
+sleep $TMOD_IDLE_CHECK_OFFSET
+
+echo "" > "$players"
+inject playing && sleep .2
+if ! grep -q "[1-9]" "$players"; then
+    inject "exit"
+fi

inject.sh

@@ -1,3 +1,6 @@
 #!/bin/sh
 
-tmux send-keys "$1" Enter
+# If no worlds exist, don't bother sending any commands
+ls /terraria/ModLoader/Worlds/*.wld >/dev/null || exit
+
+tmux send-keys "$1" Enter