Upgrading a service's Docker Compose file requires careful planning, testing, and a reliable backup strategy to ensure a smooth transition. This guide outlines the key steps involved in the upgrade process while maintaining best practices as described on the Docker Compose Setup for a Service page.

Upgrade Process

1. Prepare a Test Environment

• Copy Service Storage:
  Copy all storage data from the primary server to Server2.
  Path: /srv/service-name/storages
• Verify Data Integrity:
  Ensure all relevant data has been successfully transferred to the test server.

2. Obtain the Latest Docker Compose File

• Retrieve New File:
  Download the latest docker-compose.yml from the official GitHub repository or website of the service.
• Save for Comparison:
  Store the new file locally to compare it with the existing configuration.

3. Compare Docker Compose Files

• Image Version Updates Only:
  If the only difference is an image version change, update the existing file by replacing all image versions accordingly.
• Additional Changes:
  If there are other modifications, plan how to integrate them while adhering to the principles detailed on the Docker Compose Setup for a Service page.

4. Test the Updated Service on Server2

• Deploy:
  Run the updated configuration on Server2.
• Verify Functionality:
  Test critical functions such as login, data processing, and overall execution.
• User Testing:
  Engage at least two additional users who rely on the service to perform independent tests.

5. Backup the Current Environment on the Main Server

• Data Backup:
  Create a backup of all service data located in /srv/service-name.
• Server Snapshot:
  Use your server management portal (Hetzner) to take a snapshot for an easy rollback if necessary.
• Docker Compose Backup:
  Save the current Docker Compose file as docker-compose-{date}.yml (replace {date} with the current date).

6. Deploy the Upgrade on the Main Server

• Shut Down the Old Service:
  Execute the following command to stop the existing service:

  docker compose -f docker-compose-{date}.yml down 
  

• Launch the New Service:
  Start the new service with:

  docker compose up -d
  

• Monitor Logs:
  Check logs and monitor performance for any issues during the transition.

7. Post-Deployment Testing

• Comprehensive Testing:
  Repeat the testing procedures performed on Server2 (login, data integrity, execution).
• Team Involvement:
  Recommend that more team members test the service to ensure complete validation.

8. Rollback Plan (If Needed)

• Immediate Reversion:
  If critical issues are detected, revert to the backup snapshot and restore the previous Docker Compose file.
• Document Issues:
  Record any discrepancies or failures to improve future upgrade processes.

By following these steps, you ensure a controlled and secure upgrade process that minimizes downtime and maintains data integrity. Always keep a tested rollback plan and engage your team in the testing phase for a comprehensive evaluation.

Good luck! 🙂