Auto Update Steamcmd Servers

#!/bin/bash

set -e

: "${APP_ID:=}"
: "${APP_DIR:=}"
: "${APP_UID:=1000}"
: "${APP_GID:=1000}"
: "${APP_DIR_INIT:=0}"
: "${CONTAINER_NAME:=}"
: "${UPDATE_SCRIPT:=}"


[[ ! -d "${APP_DIR}" && "${APP_DIR_INIT}" != "1" ]] && echo "APP_DIR [${APP_DIR}] does not exist" && exit 1

# get state of game
TEMP_FILE=$(mktemp)
URL="https://api.steamcmd.net/v1/info/${APP_ID}"
curl -X GET "${URL}" -o ${TEMP_FILE} > /dev/null 2>&1


local_buildid=$(grep -oP 'buildid.+"\K[0-9]+' ${APP_DIR}/appmanifest_${APP_ID}.acf 2>/dev/null|| echo 0)
remote_buildid=$(jq -r  '.data.[].depots.branches.public.buildid' "${TEMP_FILE}")
rm "${TEMP_FILE}"

if [[ "${local_buildid}" == "${remote_buildid}" ]]; then
    echo "no update needed - buildid local[${local_buildid}] remote[${remote_buildid}]"
    exit 0
fi

# stop container if existing and not stopped
state=$(docker ps -a -f name="^${CONTAINER_NAME}$" --format json | jq -r '.State')

if [[ ${state} == "" ]];then
    echo "Container [${CONTAINER_NAME}] does not exist (check ENV CONTAINER_NAME variable)"
elif [[ ! ${state} =~ exited ]];then
    echo "stopping container [${CONTAINER_NAME}]"
    docker stop "${CONTAINER_NAME}"
    stopped=1
fi

# update by script / default cmd
if [[ -x "${UPDATE_SCRIPT}" ]];then
    echo "UPDATE BY SCRIPT [${UPDATE_SCRIPT}]"
    ${UPDATE_SCRIPT}
else
    # create directory and fix permissions
    if [[ ! -d "${APP_DIR}" ]];then
        mkdir -p "${APP_DIR}"
    fi
    ts=$(date +'%s')

    chown -R 1000:1000 "${APP_DIR}"
    cmd="docker run --network host --rm -it --name=${CONTAINER_NAME:-steam_$ts}_updater -v ${APP_DIR}:/home/steam/Steam/steamapps:rw cm2network/steamcmd /home/steam/steamcmd/steamcmd.sh +login anonymous +app_update ${APP_ID} validate +quit"
    echo "UPDATE BY COMMAND [${cmd}]"
    $cmd
    chown -R ${APP_UID}:${APP_GID} "${APP_DIR}"
fi

[[ ${stopped} -eq 1 ]] && echo "starting docker container [${CONTAINER_NAME}]" && docker start "${CONTAINER_NAME}"