postgres-cron-backup

Run pg_dump to backup your databases periodically using the cron task manager in the container. Your backups are saved in /backup. You can mount any directory of your host or a docker volumes in /backup. Othwerwise, a docker volume is created in the default location.

Usage:

docker container run -d \
       --env POSTGRES_USER=root \
       --env POSTGRES_PASS=my_password \
       --link postgres
       --volume /path/to/my/backup/folder:/backup
       ghcr.io/mentos1386/postgres-cron-backup

Variables

POSTGRES_HOST: The host/ip of your postgres database.
POSTGRES_PORT: The port number of your postgres database.
POSTGRES_USER: The username of your postgres database.
POSTGRES_PASS: The password of your postgres database.
POSTGRES_PASS_FILE: The file in container where to find the password of your postgres database (cf. docker secrets). You should use either POSTGRES_PASS_FILE or POSTGRES_PASS (see examples below).
POSTGRES_DATABASE: The database name to dump. Default: --all-databases.
POSTGRESDUMP_OPTS: Command line arguments to pass to pg_dump (see pg_dump documentation).
CRON_TIME: The interval of cron job to run pg_dump. 0 3 * * sun by default, which is every Sunday at 03:00. It uses UTC timezone.
MAX_BACKUPS: The number of backups to keep. When reaching the limit, the old backup will be discarded. No limit by default.
INIT_BACKUP: If set, create a backup when the container starts.
INIT_RESTORE_LATEST: If set, restores latest backup.
TIMEOUT: Wait a given number of seconds for the database to be ready and make the first backup, 10s by default. After that time, the initial attempt for backup gives up and only the Cron job will try to make a backup.
GZIP_LEVEL: Specify the level of gzip compression from 1 (quickest, least compressed) to 9 (slowest, most compressed), default is 6.
USE_PLAIN_SQL: If set, back up and restore plain SQL files without gzip.
TZ: Specify TIMEZONE in Container. E.g. "Europe/Berlin". Default is UTC.

If you want to make this image the perfect companion of your Postgres container, use docker-compose. You can add more services that will be able to connect to the Postgres image using the name my_postgres, note that you only expose the port 5432 internally to the servers and not to the host:

Docker-compose with POSTGRES_PASS env var:

version: "2"
services:
  postgres:
    image: postgres
    container_name: my_postgres
    expose:
      - 5432
    volumes:
      - data:/var/lib/postgresql/data
    environment:
      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
      - POSTGRES_DATABASE=${DATABASE_NAME}
    restart: unless-stopped

  postgres-cron-backup:
    image: ghcr.io/mentos1386/postgres-cron-backup
    depends_on:
      - postgres
    volumes:
      - ${VOLUME_PATH}/backup:/backup
    environment:
      - POSTGRES_HOST=my_postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASS=${POSTGRES_PASSWORD}
      - MAX_BACKUPS=15
      - INIT_BACKUP=0
      # Every day at 03:00
      - CRON_TIME=0 3 * * *
      # Make it small
      - GZIP_LEVEL=9
    restart: unless-stopped

volumes:
  data:

Docker-compose using docker secrets:

The database root password passed to docker container by using docker secrets.

In example below, docker is in classic 'docker engine mode' (iow. not swarm mode) and secret source is a local file on host filesystem.

Alternatively, secret can be stored in docker secrets engine (iow. not in host filesystem).

version: "3.7"

secrets:
  postgres_password:
    # Place your secret file somewhere on your host filesystem, with your password inside
    file: ./secrets/postgres_password

services:
  postgres:
    image: postgres
    container_name: my_postgres
    expose:
      - 3306
    volumes:
      - data:/var/lib/postgres/data
    environment:
      - POSTGRES_DATABASE=${DATABASE_NAME}
      - POSTGRES_PASS_FILE=/run/secrets/postgres_password
    secrets:
      - postgres_password
    restart: unless-stopped

  backup:
    build: .
    image: ghcr.io/mentos1386/postgres-cron-backup
    depends_on:
      - postgres
    volumes:
      - ${VOLUME_PATH}/backup:/backup
    environment:
      - POSTGRES_HOST=my_postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASS_FILE=/run/secrets/postgres_password
      - MAX_BACKUPS=10
      - INIT_BACKUP=1
      - CRON_TIME=0 0 * * *
    secrets:
      - postgres_password
    restart: unless-stopped

volumes:
  data:

Restore from a backup

List all available backups :

See the list of backups in your running docker container, just write in your favorite terminal:

docker container exec <your_postgres_backup_container_name> ls /backup

Restore using a compose file

To restore a database from a certain backup you may have to specify the database name in the variable POSTGRES_DATABASE:

postgres-cron-backup:
    image: ghcr.io/mentos1386/postgres-cron-backup
    command: "/restore.sh /backup/201708060500.${DATABASE_NAME}.sql.gz"
    depends_on:
      - postgres
    volumes:
      - ${VOLUME_PATH}/backup:/backup
    environment:
      - POSTGRES_HOST=my_postgres
      - POSTGRES_USER=postgres
      - POSTGRES_PASS=${POSTGRES_PASSWORD}
      - POSTGRES_DATABASE=${DATABASE_NAME}

Restore using a docker command

docker container exec <your_postgres_backup_container_name> /restore.sh /backup/<your_sql_backup_gz_file>

if no database name is specified, restore.sh will try to find the database name from the backup file.

mentos1386/docker-postgres-cron-backup