Update Database Containers and Others Reliably

#docker #docker-compose #linux #automation #backup

Containers that don't have a built in script

  1. Stop the application (docker-compose down)
  2. Start just the database (docker-compose up -d db)
  3. Export all databases on the server into plaintext (pg_dumpall -U username > data.sql)
  4. Stop the database (docker-compose down)
  5. Remove the contents of the database directory, wherever you’ve mounted in /var/lib/postgres
  6. Update the tag you are using, and pull the new container (postgres:12-alpine → postgres:14-alpine)
  7. Start just the database (docker-compose up -d db). This will recreate a fresh database, using the credentials from the environment.
  8. Import the data into the new database (psql -U username < data.sql)
  9. Stop the database container (docker-compose down)
  10. Start everything (docker-compose up -d)

Credits