update_check.sh

#!/usr/bin/env bash

set -m

# Use a lock file to determine if we're already checking for updates
if ! mkdir /tmp/update_check.lock; then
    printf "Failed to aquire lock.\n" >&2
    exit 1
fi
trap 'rm -rf /tmp/update_check.lock' EXIT  # remove the lockdir on exit

# Check if restart app is already running and bail out if so
#IS_RUNNING=`pgrep -fl restart_app`
#if [ $IS_RUNNING -ge 1 ]; then
#    echo "Update checker is already running.."
#    exit
#fi

# Check if we are auto-updating or not
if [ "$RUST_UPDATE_CHECKING" = "1" ]; then
	echo "Checking Steam for updates.."
else
	exit
fi

# Get the old build id (default to 0)
OLD_BUILDID=0
if [ -f "/steamcmd/rust/build.id" ]; then
	OLD_BUILDID="$(cat /steamcmd/rust/build.id)"
fi

# Minimal validation for the update branch
STRING_SIZE=${#RUST_UPDATE_BRANCH}
if [ "$STRING_SIZE" -lt "1" ]; then
	RUST_UPDATE_BRANCH=public
fi

# Remove the old cached app info if it exists
if [ -f "/root/Steam/appcache/appinfo.vdf" ]; then
	rm -fr /root/Steam/appcache/appinfo.vdf
fi

# Get the new build id directly from Steam
NEW_BUILDID="$(./steamcmd/steamcmd.sh +login anonymous +app_info_update 1 +app_info_print "258550" +quit | grep -EA 1000 "^\s+\"branches\"$" | grep -EA 5 "^\s+\"$RUST_UPDATE_BRANCH\"$" | grep -m 1 -EB 10 "^\s+}$" | grep -E "^\s+\"buildid\"\s+" | tr '[:blank:]"' ' ' | tr -s ' ' | sed "s/ buildid //g" | xargs)"

# Check that we actually got a new build id
STRING_SIZE=${#NEW_BUILDID}
if [ "$STRING_SIZE" -lt "6" ]; then
	echo "Error getting latest server build id from Steam.."
	exit
fi

# Skip update checking if this is the first time
if [ ! -f "/steamcmd/rust/build.id" ]; then
	echo "First time running update check (server build id not found), skipping update.."
	echo $NEW_BUILDID > /steamcmd/rust/build.id
	exit
else
	STRING_SIZE=${#OLD_BUILDID}
	if [ "$STRING_SIZE" -lt "6" ]; then
		echo "First time running update check (server build id empty), skipping update.."
		echo $NEW_BUILDID > /steamcmd/rust/build.id
		exit
	fi
fi

# Check if the builds match and quit if so
if [ "$OLD_BUILDID" = "$NEW_BUILDID" ]; then
	echo "Build id $OLD_BUILDID is already the latest, skipping update.."
	exit
else
	# Use a lock file to determine if we're already checking for updates
	if ! mkdir /tmp/restart_app.lock; then
	    printf "Failed to aquire lock.\n" >&2
	    exit 1
	fi
	
	echo "Latest server build id ($NEW_BUILDID) is newer than the current one ($OLD_BUILDID), waiting for client update.."
	echo $NEW_BUILDID > /steamcmd/rust/build.id
	exec node /restart_app/app.js
	child=$!
	wait "$child"
fi