entrypoint.sh

#!/bin/sh

set -e

TEMP_CONFIG="/tmp/config.json"

# Resolve and output the below variables to /tmp/config.json
node --enable-source-maps /usr/app/dist/src/entrypoint-config.js
TZ=$(cat $TEMP_CONFIG | jq -r ".timezone")
RUN_ON_STARTUP=$(cat $TEMP_CONFIG | jq -r ".runOnStartup")
RUN_ONCE=$(cat $TEMP_CONFIG | jq -r ".runOnce")
CRON_SCHEDULE=$(cat $TEMP_CONFIG | jq -r ".cronSchedule")

if [ ! -e /etc/localtime ]; then
    echo "Setting localtime: $TZ"
    ln -snf /usr/share/zoneinfo/"$TZ" /etc/localtime
fi
if [ ! -e /etc/timezone ]; then
    echo "Setting timezone: $TZ"
    echo "$TZ" > /etc/timezone
fi

# Set the DISTRO variable
export DISTRO=$(grep '^ID=' /etc/os-release | cut -d'=' -f2)
echo "Detected distro: $DISTRO"

# If runOnStartup is set, run it once before setting up the schedule
echo "Run on startup: ${RUN_ON_STARTUP}"
if [ "$RUN_ON_STARTUP" = "true" ]; then
    node --enable-source-maps /usr/app/dist/src/index.js
fi

# If runOnce is not set, schedule the process
echo "Run once: ${RUN_ONCE}"
if [ "$RUN_ONCE" = "false" ]; then
    echo "Setting cron schedule as ${CRON_SCHEDULE}"
    if [ "$DISTRO" = "alpine" ]; then
        # Add the command to the crontab
        echo "${CRON_SCHEDULE} cd /usr/app && node --enable-source-maps /usr/app/dist/src/index.js" | crontab -
        # Run the cron process. The container should halt here and wait for the schedule.
        /usr/sbin/crond -f -l 8
    else
        # Debian cron wipes the environment, so we save it to a script to load in cron
        printenv | sed 's/^\(.*\)$/export \1/g' > /root/project_env.sh
        # Add the command to the crontab. Debian cron doesn't ensure single instance, so we use flock to ensure it
        echo "${CRON_SCHEDULE} . /root/project_env.sh && cd /usr/app && flock -n /var/lock/epicgames.lock node --enable-source-maps /usr/app/dist/src/index.js > /proc/1/fd/1 2>/proc/1/fd/2" | crontab -
        # Run the cron process. The container should halt here and wait for the schedule.
        cron -f
    fi
fi
echo "Exiting..."