backup.rst

Docker database backup

This page explains how to automate the backup process of a Docker database on a daily basis and restore the backup snapshot created by the backup script.

Note: This documentation assumes that you are using a Linux-based system.

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Here's how the script works

The script automates the process of creating PostgreSQL database backups from a Docker container. It generates a backup file(.dump) using the pg_dump utility in PostgreSQL and stores these files in the path configured in $BACKUP_DIR environment variable which is binded to /backups in the docker container. Backup files older than $DB_BACKUP_RETENTION_PERIOD days are deleted when the script is executed by default it is set to 7 days. The backup file is saved with the name care_backup_%Y%m%d%H%M%S.sql.

Set up a cronjob

Backup your database running on docker automatically everyday by initiating a cronjob.

Install the package

For a fedora based system:

sudo dnf install crond

For a debian based system:

sudo apt install cron

Automate the cronjob

Note: Make sure you are inside the care directory at the time of executing the following.

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Open up a crontab:

crontab -e

Add the cronjob:

0 0 * * * "/scripts/backup.sh"

List the cron jobs

crontab -l

Check the status of cron

For a fedora based os:

sudo systemctl status crond

For a debian based os:

sudo systemctl status cron

Verify the cron job

To verify the cron job is working:

1. Check the system logs for cron activity, which is usually somewhere in

   /var/log/

2. Monitor the backup directory for new files after the scheduled time

Restoration of the Database

We are basically deleting the container's existing database and creating a new database with the same name. Then we will use pg_restore to restore the database. Run the following commands in your terminal.

Make sure you have stopped all the containers except the db before proceeding. And be inside the care directory at the time of executing the following.

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Delete the existing database:

docker exec -it $(docker ps --format '{{.Names}}' | grep 'care-db') psql -U postgres -c "DROP DATABASE IF EXISTS care;"

Create the new database:

docker exec -it $(docker ps --format '{{.Names}}' | grep 'care-db') psql -U postgres -c "CREATE DATABASE care;"

Execute and copy the name of the file you want to restore the database with:

sudo ls ./care-backups

Restore the database:

Replace <file name> with your file name which looks like this care_backup_%Y%m%d%H%M%S.sql

docker exec -it $(docker ps --format '{{.Names}}' | grep 'care-db') pg_restore -U postgres -d care /backups/<file name>.dump

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There are way easier ways to do this. If anyone has any particular idea, feel free to make a PR :)