Implement time to live to determine when to shutdown

.gitignore

@@ -1 +1,2 @@
+live_until.txt
 *.swp

autoshutdown.sh

@@ -5,7 +5,7 @@
 
 SERVER_DIR='/home/ubuntu/minecraft/servers/kincls'
 TMUX_NAME='minecraft kincls server'
-EMPTY_COUNTER="$SERVER_DIR/empty_counter.txt"
+LIVE_UNTIL="/home/ubuntu/minecraft/live_until.txt"
 
 json_parse() {
     cat - | python3 -c "import sys, json; print(json.load(sys.stdin)['$1'])"
@@ -15,32 +15,33 @@ silent_exitcode() {
     $* > /dev/null 2>&1
 }
 
-empty_count() {
+extend_ttl() {
-    if [ ! -f "$EMPTY_COUNTER" ]; then
+    # Extend time to live 10 minutes at a time
-        # File not existing
+    new_ttl="$(date -d '+10 min' +%s)"
-        echo "0"
+    old_ttl="$(date -d "$(cat "$LIVE_UNTIL")" +%s)"
-    else
+    if [ ! -f "$LIVE_UNTIL" ] || [ "$new_ttl" -ge "$old_ttl" ]; then
-        cat "$EMPTY_COUNTER"
+        # If LIVE_UNTIL file not existing or new time to live longer
+        echo "Extending time to live until $(date -d "@$new_ttl")"
+        date -d "@$new_ttl" > "$LIVE_UNTIL"
     fi
+    exit 0
 }
 
-empty_incr() {
+soft_poweroff() {
-    c="$(empty_count)"
+    # Poweroff, if time to live has expired
-    if [ "$c" -gt 10 ]; then
+    ttl="0"
-        echo "Server empty for more than 10 minutes, shutting down"
+    if [ -f "$LIVE_UNTIL" ]; then
+        ttl="$(date -d "$(cat "$LIVE_UNTIL")" +%s)"
+    fi
+    echo "Time to live is $(cat "$LIVE_UNTIL")"
+    if [ "$(date +%s)" -ge "$ttl" ]; then
+        echo "Server empty longer than grace time, shutting down"
         empty_reset # Needs to be 0 next time server starts
         tmux send-keys -t "$TMUX_NAME.0" "stop" ENTER
         sleep 5
         $(sudo /sbin/shutdown -P +1)
-    else
-        echo "Empty count $c. Incrementing"
-        echo "$((c+1))" > "$EMPTY_COUNTER"
     fi
-}
+    exit 1
-
-empty_reset() {
-    echo "Resetting empty counter"
-    echo 0 > "$EMPTY_COUNTER"
 }
 
 tmux_running() {
@@ -56,16 +57,14 @@ echo "$(date) [$n_logins logins]"
 
 if [ "$n_logins" -gt 0 ]; then
     echo "Keep alive as there are active ssh sessions"
-    empty_reset
+    extend_ttl
-    exit 0
 fi
 
 if tmux_running; then
     : #echo "Tmux running"
 else
     echo "Tmux not running"
-    empty_incr
+    soft_poweroff
-    exit 1
 fi
 
 if server_responsive; then
@@ -73,14 +72,11 @@ if server_responsive; then
     echo "Server responsive. $n_players players online"
     if [ "$n_players" -gt 0 ]; then
         # Keep alive as players are online
-        empty_reset
+        extend_ttl
-        exit 0
     else
-        empty_incr
+        soft_poweroff
-        exit 1
     fi
 else
     echo "Server unresponsive"
-    empty_incr
+    soft_poweroff
-    exit 1
 fi

services/ensure_running.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=Launch minecraft server
+
+[Service]
+Type=oneshot
+ExecStart=/home/ubuntu/minecraft/ensure_running.sh
+
+[Install]
+WantedBy=multi-user.target

services/set_initial_ttl.service

@@ -0,0 +1,9 @@
+[Unit]
+Description=Let server live for 1h after initial boot
+
+[Service]
+Type=oneshot
+ExecStart=/bin/sh -c 'date -d "+1 hour" > /home/ubuntu/minecraft/live_until.txt'
+
+[Install]
+WantedBy=multi-user.target