Manage GitLab Container Registry garbage collection in read-only mode

gitlab-registry-garbage-collect.sh

#!/bin/sh

#
# GitLab Container Registry garbage collector script 
# you can configure with cron jobs to run garbage collection nightly
# 
# Usage:
# 
# - Update your /etc/gitlab/gitlab.rb to add 'REGISTRY-STORAGE-READONLY-ENABLE-MARKER' marker
#   as comment on registry config so that script can automatically update it
#
#   registry['storage'] = {
#     'maintenance' => {
#         'readonly' => {
#             'enabled' => false # REGISTRY-STORAGE-READONLY-ENABLE-MARKER
#         }
#       }
#   }
# 
# - Copy this script at /usr/local/sbin/gitlab-registry-garbage-collect.sh
# - Create cron jobs:
#    
#   # Start garbage collect at night
#   0  23  *  *  *    /usr/local/sbin/gitlab-registry-garbage-collect.sh start
#   # Stop garbage collect in the morning
#   0  6  *  *  *    /usr/local/sbin/gitlab-registry-garbage-collect.sh stop
# 
# On start:
# - Updates /etc/gitlab/gitlab.rb and reconfigure GitLab instance with Container Registry in read-only mode
# - Start garbage collection in the background and keep PID of process in a temporary file
#
# On stop:
# - Kill garbage collection process using PID file created on start
# - Updates /etc/gitlab/gitlab.rb and reconfigure GitLab instance with Container Registry without read-only mode
# 
# Logs and PID file are stored under /tmp/gitlab-registry-garbage-collect by default, override with CLEANUP_WORKDIR var
#  

# Ensure cleanup workdir exists
CLEANUP_WORKDIR="${CLEANUP_WORKDIR:-/tmp/gitlab-registry-garbage-collect}"
PID_FILE="$CLEANUP_WORKDIR/cleanup.pid"
mkdir -p $CLEANUP_WORKDIR

cleanup_start(){
    gitlab_registry_readonly "true"

    /opt/gitlab/embedded/bin/registry garbage-collect -m /var/opt/gitlab/registry/config.yml > $CLEANUP_WORKDIR/cleanup.log 2>&1 &
    echo $! > $PID_FILE
}

cleanup_stop() {
    if [ -f $PID_FILE ]; then
      echo "Killing cleanup process $(cat $PID_FILE)"
      kill "$(cat $PID_FILE)"
      rm "$PID_FILE"
    else
        echo "No PID file found at $PID_FILE. Is cleanup running?"
    fi

    gitlab_registry_readonly "false"
}

# Enable/disable Gitlab registry read-only mode
gitlab_registry_readonly() {
    echo "Setting GitLab Registry read-only: $1"

    sed -i -r "s/(^.*'enabled').*# REGISTRY-STORAGE-READONLY-ENABLE-MARKER/\1 => $1 # REGISTRY-STORAGE-READONLY-ENABLE-MARKER/g" /etc/gitlab/gitlab.rb

    echo "Running gitlab-ctl reconfigure. May take a few seconds... "
    echo "If needed see logs at $CLEANUP_WORKDIR/gitlab-reconfigure.log"
    gitlab-ctl reconfigure > $CLEANUP_WORKDIR/gitlab-reconfigure.log 2>&1
    if [ $? -ne 0 ]; then
        echo "gitlab-ctl reconfigure failed. Check logs at $CLEANUP_WORKDIR/gitlab-reconfigure.log."
        exit 2
    fi
}

help(){
    echo "Run GitLab Registry cleanup in read-only mode."
    echo "Detailed execution logs are saved under $CLEANUP_WORKDIR/*.log."
    echo 
    echo "Usage:"
    echo 
    echo "$0 start"
    echo "$0 stop"
    echo "$0 help"
}

case "$1" in
    "start") cleanup_start;;
    "stop") cleanup_stop;;
    "help") help;;
    "--help") help;;
    *) echo "Unknwon argument $1." && help && exit 1
esac

echo "Done !"