Backup/Restore a dockerized PostgreSQL database

Question

Backup your databases

docker exec -t your-db-container pg_dumpall -c -U postgres > dump_`date +%d-%m-%Y"_"%H_%M_%S`.sql

Restore your databases

cat your_dump.sql | docker exec -i your-db-container psql -U postgres

I think you can also use a postgres backup container which would backup your databases within a given time duration.

  pgbackups:
    container_name: Backup
    image: prodrigestivill/postgres-backup-local
    restart: always
    volumes:
      - ./backup:/backups
    links:
      - db:db
    depends_on:
      - db
    environment:
      - POSTGRES_HOST=db
      - POSTGRES_DB=${DB_NAME} 
      - POSTGRES_USER=${DB_USER}
      - POSTGRES_PASSWORD=${DB_PASSWORD}
      - POSTGRES_EXTRA_OPTS=-Z9 --schema=public --blobs
      - SCHEDULE=@every 0h30m00s
      - BACKUP_KEEP_DAYS=7
      - BACKUP_KEEP_WEEKS=4
      - BACKUP_KEEP_MONTHS=6
      - HEALTHCHECK_PORT=81

Backup Database

generate sql:

• docker exec -t your-db-container pg_dumpall -c -U your-db-user > dump_$(date +%Y-%m-%d_%H_%M_%S).sql

to reduce the size of the sql you can generate a compress:

• docker exec -t your-db-container pg_dumpall -c -U your-db-user | gzip > ./dump_$(date +"%Y-%m-%d_%H_%M_%S").gz

Restore Database

• cat your_dump.sql | docker exec -i your-db-container psql -U your-db-user -d your-db-name

to restore a compressed sql:

• gunzip < your_dump.sql.gz | docker exec -i your-db-container psql -U your-db-user -d your-db-name

PD: this is a compilation of what worked for me, and what I got from here and elsewhere. I am beginning to make contributions, any feedback will be appreciated.

cat db.dump | docker exec ... way didn't work for my dump (~2Gb). It took few hours and ended up with out-of-memory error.

Instead, I cp'ed dump into container and pg_restore'ed it from within.

Assuming that container id is CONTAINER_ID and db name is DB_NAME:

# copy dump into container
docker cp local/path/to/db.dump CONTAINER_ID:/db.dump

# shell into container
docker exec -it CONTAINER_ID bash

# restore it from within
pg_restore -U postgres -d DB_NAME --no-owner -1 /db.dump

Okay, I've figured this out. Postgresql does not detect changes to the folder /var/lib/postgresql once it's launched, at least not the kind of changes I want it do detect.

The first solution is to start a container with bash instead of starting the postgres server directly, restore the data, and then start the server manually.

The second solution is to use a data container. I didn't get the point of it before, now I do. This data container allows to restore the data before starting the postgres container. Thus, when the postgres server starts, the data are already there.