martlark/pg_dump repository overview

⁠martlark/pg_dump

Docker image with pg_dump running as a cron task. Find the image here: https://hub.docker.com/repository/docker/martlark/pg_dump⁠

⁠Usage

Import a PostgreSQL database into this container and mount a volume to the containers /dump folder. Backups will appear in this volume. Optionally set up cron job schedule (default is 0 1 * * * - runs every day at 1:00 am).

⁠Environment Variables:

⁠AWS S3

Automatic copy of backups to AWS S3 buckets is supported using the s3cmd tool. Add the S3 environment variables as listed in the Environment Variables table.

⁠Sync as default

By default, only backups in the container volume are retained in a bucket. These default options are used :

--delete-removed      Delete destination objects with no corresponding
                        source file [sync]
--delete-after        Perform deletes after new uploads [sync]

If required to retain backups on the local or bucket, then use:

S3_SYNC_OPTION="--no-delete-removed"

⁠Example

version: "3.9"
services:
  backup:
    build: .
    environment:
      - POSTGRES_PASSWORD=SumPassw0rdHere
      - POSTGRES_DB=postgres
      - PGHOST=database # The hostname of the PostgreSQL database to dump
      - CRON_SCHEDULE=*/15 * * * * # Every 15 minutes
      - RETAIN_COUNT=3 # Keep this number of backups
      - S3_BUCKET_PATH=s3://${S3_BUCKET_NAME}/
      - S3_SECRET_KEY=${S3_SECRET_KEY}
      - S3_ACCESS_KEY=${S3_ACCESS_KEY}
    volumes:
      - ./persistent/dump:/dump
    restart: unless-stopped

⁠Not AWS

Copying to non AWS buckets can be achieved by using S3_HOSTNAME and S3_HOST_BUCKET.

⁠s3cmd

The s3cmd tool is used to synchronize backups to buckets. Please refer to the online documentation for a full list of options.

https://s3tools.org/usage

⁠Optional Controls

By default, this container executes as the postgres user. Using a non-root user for your container is always a safer route and should be one of your first modifications.

The POSTGRES_PASSWORD field can either be set via environment variable or via docker secrets. Again, for security reasons, it is always recommended to use docker secrets for security concerns.

If using the docker secrets, set the POSTGRES_PASSWORD_FILE field, warning this overrides POSTGRES_PASSWORD and PGPASSWORD. An example secrets file can be found below in the docker-compose area.

PGPORT is the exposed port in the container, so it is recommended not to change this.

Synchronization to S3 requires setting S3_ACCESS_KEY, S3_SECRET_KEY, and S3_BUCKET_PATH. The other S3_ variables are only required if you are connecting to a non-AWS S3 implementation.

⁠Docker Compose

Always run as separate services with pgdump running alongside the main Postgres database service.

⁠Example of running with separate services.

version: "3.9"
services:
  database:
    image: postgres:12.16
    volumes:
      - ./persistent/data:/var/lib/postgresql/data
    environment:
      - POSTGRES_PASSWORD=SumPassw0rdHere
      - POSTGRES_DB=postgres
    restart: unless-stopped

  postgres-backup:
    image: martlark/pg_dump:12.16
    container_name: postgres-backup
    links:
      - database:db # Maps as "db"
    environment:
      - PGPASSWORD=SumPassw0rdHere
      - CRON_SCHEDULE=0 3 * * * # Every day at 3am
      - RETAIN_COUNT=4 # Keep this number of backups
    volumes:
      - ./persistent/data:/dump

⁠Example passwords file

POSTGRES_PASSWORD=SumPassw0rdHere

⁠Tagged versions

Generally an attempt is made to provide versions for the latest major and minor Postgres release. Usually previous tagged versions will be maintained.

Versions available on docker hub are:

11.19 11.21 12.12 12.16 13.12 14.7 14.9 15.2 15.4

latest is 15.4