docker_database_dumper

Periodically dump a MySQL/MariaDB or PostgreSQL database to the local system and keep only a maximum number of dumps with a Docker container. Supports healthchecks.io.

Links:

• Source code on GitHub
• Image on DockerHub

Supported tags

• mariadb for a MariaDB database
• mysql for a MySQL database
• For postgres use the correct version:
  • postgres-16 for PostgreSQL 16
  • postgres-15 for PostgreSQL 15
  • postgres-14 for PostgreSQL 14
  • postgres-13 for PostgreSQL 13
  • postgres-12 for PostgreSQL 12

Why

I wanted a simple container which periodically backup my MySQL and PostgreSQL databases. I wanted to be allerted of failures using healthchecks.io.

I use this image together with a classic file backup setup which saves all the dumps in an incremental way on a remote server.

Usage

Docker:

docker run -e DUMPER_HOST=db_container -e DUMPER_PORT=5432 -e DUMPER_DATABASE=db_name
-e DUMPER_USER=user -e DUMPER_PASSWORD=password 
-e PUID=1000 -e PGID=1000 
-v ./dumps:/dumps paolobasso/database_dumper:postgres-15

Docker Compose:

version: '3.8'

services:
  postgres_db:
    image: postgres:15
    restart: unless-stopped
    container_name: postgres_db
    volumes:
      - ./postgres/db:/var/lib/postgresql/data
    environment:
      - POSTGRES_DB=mydatabase
      - POSTGRES_USER=myuser
      - POSTGRES_PASSWORD=${DUMPER_PASSWORD}
    networks:
      - db

  database_dumper_postgres:
    image: paolobasso/database_dumper:postgres-14
    restart: unless-stopped
    depends_on:
      - postgres_db
    container_name: database_dumper_postgres
    volumes:
      - ./postgres/dumps:/dumps
    environment:
      - PGID=1000
      - PUID=1000
      - DUMPER_DATABASE=mydatabase
      - DUMPER_HOST=postgres_db
      - DUMPER_USER=myuser
      - DUMPER_PASSWORD=${DUMPER_PASSWORD}
      - DUMPER_KEEP=7
      - DUMPER_SCHEDULE=0 3 * * *
      - DUMPER_HEALTHCHECKS_URL=${DUMPER_HEALTHCHECKS_URL}
    networks:
      - db

networks:
  db:
    driver: bridge

Environment Variables

Variable	Description	Default
PUID	The UserID of the user who will own the dumps.
PGID	The GroupID of the user who will own the dumps.
DUMPER_DATABASE	The name of the database to dump.
DUMPER_HOST	Database connection parameter; host to connect to.
DUMPER_PASSWORD	Database connection parameter; password to connect with.
DUMPER_PORT	Database connection parameter; port to connect to.	3306 or 5432
DUMPER_USER	Database connection parameter; user to connect with.
DUMPER_SCHEDULE	Cron-schedule specifying the interval between dumps.	0 3 * * *
DUMPER_KEEP	The number of dumps to keep.	7
DUMPER_HEALTHCHECKS_URL	The url to an healthchecks.io endpoint.

User / Group Identifiers

To find the correct values of PUID and PGID use id user as below:

$ id username
  uid=1000(username) gid=1000(username) groups=1000(username)

Setting up healthchecks

If you want to use healthchecks.io in order to be informed if the dump fails you need to set the environment variable DUMPER_HEALTHCHECKS_URL.

Making a dump instantly

Run a one off dump:

docker run DUMPER_HOST=db_container -e DUMPER_PORT=5432 -e DUMPER_DATABASE=db_name
-e DUMPER_USER=user -e DUMPER_PASSWORD=password 
-e PUID=1000 -e PGID=1000 
-v ./dumps:/dumps --entrypoint=/dump.sh
paolobasso/database_dumper:postgres-15

If the container is running in a deamon mode (i.e. using docker-compose) but you want to run a backup instantly and don't wait for the schedule then:

docker exec database_dumper /dump.sh