Add Example Documentation To Restore Volumes From A Backup

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Description

Restoring volumes from a backup can be a complex process, especially for those who are new to Docker and containerization. After spending an hour trying to apply the steps in the Restore Volumes from a Backup guide, I was finally able to successfully restore from a backup and thought others might benefit from my experience. In this article, we will provide a step-by-step example of how to backup a Gitea service via the CLI and then perform a restoration.

Backup & Restore Example

In this example, we will backup a Gitea service via the CLI and then perform a restoration. Our docker-compose.yaml file will be located at gitea/docker-compose.yaml.

Setup

First, we need to create a docker-compose.yaml file that defines our Gitea service. The file should contain the following configuration:

services:
  server:
    image: docker.io/gitea/gitea:1.23.1-rootless
    restart: always
    volumes:
      - data:/var/lib/gitea
      - config:/etc/gitea
    cap_add:
      - SYS_ADMIN
      - DAC_READ_SEARCH
    ports:
      - "3000:3000"
      - "2222:2222"

volumes:
  data:
  config:

To set up the environment, follow these steps:

  1. Save the docker-compose.yaml file to a similar path and run docker-compose up -d
  2. Navigate to http://localhost:3000 and run through a basic setup of Gitea to ensure you have data to benchmark that backup and restoration is working correctly. If done correctly, you should be able to delete the original volumes and restore from your backups with all of your data intact.

Backup Steps

To backup the Gitea service, we need to determine the volumes to be backed up and the directory where we want to place the backups. In this case, we will backup the gitea_config and gitea_data volumes.

  1. Determine the volumes to be backed up, in this case gitea_config and gitea_data
  2. Determine the directory you want the backups placed in as we will need to access them later, lets say the user home directory /home/user/Downloads
  3. Run the manual backup process for each volume
# Backup the Config volume
docker run --rm \
  -e BACKUP_FILENAME="backup-config-%Y-%m-%dT%H-%M-%S.{{ .Extension }}" \
  -v gitea_config:/backup/config/gitea \
  -v /home/clumsy/Development/gitea:/archive \
  --entrypoint backup \
  offen/docker-volume-backup:v2.43.3

# Backup the Data volume
docker run --rm \
  -e BACKUP_FILENAME="backup-data-%Y-%m-%dT%H-%M-%S.{{ .Extension }}" \
  -v gitea_data:/backup/data/gitea \
  -v /home/user/Downloads:/archive \
  --entrypoint backup \
  offen/docker-volume-backup:v2.43.3
  1. You should now have 2 backup files, 1 titled backup-data-[current timestamp].tar.gz and another one titled backup-config-[current timestamp].tar.gz
  2. If you can, go to another machine and download the backups to that machine. If you're operating on the same machine, you'll have to run docker-compose down and then delete the volumes with docker volume rm gitea_config && docker volume rm gitea_data

Restore Steps

To restore the volumes, we need to create the volumes for our services before we restore the data to them. Create your volumes using your docker-compose.yaml file, run docker-compose up -d in the gitea directory.

  1. Now starting from a clean slate, you'll first need to create the volumes for your services before you restore the data to them. Create your volumes using your docker-compose.yaml file, run docker-compose up -d in the gitea directory
  2. Once the volumes are created, you need to stop your services in order to restore the volumes, this can be done by running docker-compose down
  3. Unzip your backup data in a temporary place
tar -C /tmp -xvf backup-data-[current timestamp].tar.gz
tar -C /tmp -xvf backup-config-[current timestamp].tar.gz
  1. Restore the data in the volumes using temporary containers. To do this, we're going to mount the data volume to a temp container, copy the unzipped files from Step 3 over, and then stop and remove the container
# Mount the data volume to a temp container, copy the unzipped files from Step 3 over, and then stop and remove the container

docker run -d --name temp_restore_container -v gitea_data:/backup_restore/data/gitea alpine && docker cp /tmp/backup/data/gitea temp_restore_container:/backup_restore/data && docker stop temp_restore_container && docker rm temp_restore_container

# Mount the config volume to a temp container, copy the unzipped files from Step 3 over, and then stop and remove the container

docker run -d --name temp_restore_container -v gitea_config:/backup_restore/config/gitea alpine && docker cp /tmp/backup/config/gitea temp_restore_container:/backup_restore/config && docker stop temp_restore_container && docker rm temp_restore_container
  1. Run docker-compose up -d and your volume restoration should be complete

If you go back to http://localhost:3000 you should be able to login and see your data from before.

Conclusion

Q: What is the purpose of restoring volumes from a backup?

A: Restoring volumes from a backup is a process of recovering data from a backup file and restoring it to its original location. This is useful in case of data loss or corruption, or when you need to migrate data to a new environment.

Q: What are the benefits of restoring volumes from a backup?

A: The benefits of restoring volumes from a backup include:

  • Data recovery: Restoring volumes from a backup allows you to recover data that was lost or corrupted.
  • Data migration: Restoring volumes from a backup enables you to migrate data to a new environment, such as a new server or a different cloud provider.
  • Data backup: Restoring volumes from a backup provides a backup of your data, which can be used to recover data in case of a disaster.

Q: What are the steps involved in restoring volumes from a backup?

A: The steps involved in restoring volumes from a backup are:

  1. Backup: Create a backup of your data using a backup tool or a Docker volume backup.
  2. Restore: Restore the backup to a new location using a restore tool or a Docker volume restore.
  3. Verify: Verify that the data has been restored correctly and is accessible.

Q: What are the common challenges faced while restoring volumes from a backup?

A: The common challenges faced while restoring volumes from a backup include:

  • Data corruption: Data corruption can occur during the backup or restore process, which can result in data loss or corruption.
  • Backup failure: Backup failure can occur due to various reasons, such as network issues or backup tool errors.
  • Restore failure: Restore failure can occur due to various reasons, such as data corruption or restore tool errors.

Q: How can I troubleshoot issues while restoring volumes from a backup?

A: To troubleshoot issues while restoring volumes from a backup, you can:

  • Check the backup: Check the backup file to ensure that it is complete and not corrupted.
  • Check the restore tool: Check the restore tool to ensure that it is configured correctly and is working properly.
  • Check the data: Check the data to ensure that it is accessible and not corrupted.

Q: What are the best practices for restoring volumes from a backup?

A: The best practices for restoring volumes from a backup include:

  • Regular backups: Regular backups ensure that your data is up-to-date and can be restored in case of a disaster.
  • Backup validation: Backup validation ensures that the backup is complete and not corrupted.
  • Restore testing: Restore testing ensures that the restore process is working correctly and that the data is accessible.

Q: Can I restore volumes from a backup to a different environment?

A: Yes, you can restore volumes from a backup to a different environment. However, you need to ensure that the environment is compatible with the backup and restore tools used.

Q: Can I restore volumes from a backup to a different cloud provider?

A: Yes, you can restore volumes from a backup to a different cloud provider. However, you need to ensure that the cloud provider is compatible with the backup and restore tools used.

Q: How long does it take to restore volumes from a backup?

A: The time it takes to restore volumes from a backup depends on the size of the data, the speed of the network, and the efficiency of the restore tool. In general, it can take anywhere from a few minutes to several hours to restore volumes from a backup.