Self CICD using Cron + Git

check.sh

#!/bin/bash
#
# Helps redeploy services when there are git remote changes
#
# @usage: sudo ./check.sh [branch] [--force]
# @example: sudo ./check.sh origin/master --force

PATH=$PATH:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
FETCH=$(git fetch)
UPSTREAM=${1:-'origin/master'}
LOCAL=$(git rev-parse @)
REMOTE=$(git rev-parse "$UPSTREAM")
BASE=$(git merge-base @ "$UPSTREAM")

function rebuild() {
    echo "rebuild()"
    cd ..
    git pull
    docker-compose up -d --build
}

if [ "$2" = "--force" ]; then
    echo "$(date +%FT%T) --force rebuild"
    rebuild
elif [ $LOCAL = $REMOTE ]; then
    echo "$(date +%FT%T) Up-to-date"
elif [ $LOCAL = $BASE ]; then
    echo "$(date +%FT%T) Need to pull"
    rebuild
elif [ $REMOTE = $BASE ]; then
    echo "$(date +%FT%T) Need to push"
else
    echo "$(date +%FT%T) Diverged"
fi

install.sh

#! /bin/bash
#
# Installs updater using cron+git
# Check git every minute to compare remote with local
# Logs output to `update.log`
#
#
# 1) Cron doesnt know the script directory so find out where it is
SCRIPT_DIR=$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )
# 2) Check git remote with local, log to `update.log`
(crontab -l 2>/dev/null; echo "*/1 * * * * cd $SCRIPT_DIR && ./check.sh >> update.log 2>&1") | sudo crontab -
# 3) Keep the logs trimmed to last 1000 lines
(crontab -l 2>/dev/null; echo "0 * * * * cd $SCRIPT_DIR && tail -1000 update.log | cat > update.log") | sudo crontab -
# Done
crontab -l
echo ""
echo "Updater installed. Check the 'update.log' in a minute or two."