Docker PostgreSQL Backup

Docker image that periodically dumps a Postgres database, and uploads it to an Amazon S3 bucket.

Required environment variables

• CRON_SCHEDULE: The time schedule part of a crontab file (e.g: 15 3 * * * for every night 03:15)
• DB_HOST: Postgres hostname
• DB_PASS: Postgres password
• DB_USER: Postgres username
• DB_NAME: Name of database
• S3_PATH: Amazon S3 path in the format: s3://bucket-name/some/path
• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY
• AWS_DEFAULT_REGION

Optional environment variables

• MAIL_TO: If MAIL_TO and MAIL_FROM is specified, an e-mail will be sent, using Amazon SES, every time a backup is taken
• MAIL_FROM
• WEBHOOK: If specified, an HTTP request will be sent to this URL
• WEBHOOK_METHOD: By default the webhook's HTTP method is GET, but can be changed using this variable
• KEEP_BACKUP_DAYS: The number of days to keep backups for when pruning old backups. Defaults to 7.
• FILENAME: String that is passed into strftime() and used as the backup dump's filename. Defaults to $DB_NAME_%Y-%m-%d.

Volumes

• /data/backups - The database is dumped in into this directory

Restoring a backup

This image can also be run as a one off task to restore one of the backups. To do this, we run the container with the command: python -u /backup/restore.py [S3-filename] (S3-filename should only be the name of the file, the directory is set through the S3_PATH env variable).

The following environment variables are required:

• DB_HOST: Postgres hostname
• DB_PASS: Postgres password
• DB_USER: Postgres username
• DB_NAME: Name of database to import into
• S3_PATH: Amazon S3 directory path in the format: s3://bucket-name/some/path
• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY
• AWS_DEFAULT_REGION

Taking a one off backup

To run a one off backup job, e.g. to test that it works when setting it up for the first time, simply start the container with the docker run command set to python -u backup.py (as well as all the required environment variables set).

Docker tags

This image uses the alpine version(s) of the official postgres image as base image.

The following docker tags are available for this image, and they are based on the corresponding official postgres alpine image:

• 13, latest
• 12
• 11
• 10