Migrating Postgres 12 to 15

The old sample docker compose file used Postgres 12, which is now nearing end of life, so we've updated it to Postgres 15. Postgres major versions changes require a migration step. This document mentions some approaches you can use.

TIP

Ente itself does not use any specific Postgres 12 or Postgres 15 features, and will talk to either happily. It should also work with newer Postgres versions, but let us know if you run into any problems and we'll update this page.

Taking a backup

docker compose exec allows us to run a command against a running container. We can use it to run the pg_dumpall command on the postgres container to create a plaintext backup.

Assuming your cluster is already running, and you are in the ente/server directory, you can run the following (this command uses the default credentials, you'll need to change these to match your setup):

docker compose exec postgres env PGPASSWORD=pgpass PGUSER=pguser PG_DB=ente_db pg_dumpall >pg12.backup.sql

This will produce a pg12.backup.sql in your current directory. You can open it in a text editor (it can be huge!) to verify that it looks correct.

We won't be needing this file, this backup is recommended just in case something goes amiss with the actual migration.

If you need to restore from this plaintext backup, you could subsequently run something like:

docker compose up postgres
cat pg12.backup.sql | docker compose exec -T postgres env PGPASSWORD=pgpass psql -U pguser -d ente_db

The migration

At the high level, the steps are

1. Stop your cluster.

2. Start just the postgres container after changing the image to pgautoupgrade/pgautoupgrade:15-bookworm.

3. Once the in-place migration completes, stop the container, and change the image to postgres:15.

1. Stop the cluster

Stop your running Ente cluster.

docker compose down

2. Run pgautoupgrade

Modify your compose.yaml, changing the image for the "postgres" container from "postgres:12" to "pgautoupgrade/pgautoupgrade:15-bookworm"

diff a/server/compose.yaml b/server/compose.yaml

   postgres:
-    image: postgres:12
+    image: pgautoupgrade/pgautoupgrade:15-bookworm
     ports:

pgautoupgrade is a community docker image that performs an in-place migration.

After making the change, run only the postgres container in the cluster

docker compose up postgres

The container will start and peform an in-place migration. Once it is done, it will start postgres normally. You should see something like this is the logs

postgres-1  | Automatic upgrade process finished with no errors reported
...
postgres-1  | ...  starting PostgreSQL 15...

At this point, you can stop the container (CTRL-C).

3. Finish by changing image

Modify compose.yaml again, changing the image to "postgres:15".

diff a/server/compose.yaml b/server/compose.yaml

   postgres:
-    image: pgautoupgrade/pgautoupgrade:15-bookworm
+    image: postgres:15
     ports:

And cleanup the temporary containers by

docker compose down --remove-orphans

Migration is now complete. You can start your Ente cluster normally.

docker compose up

Migration elsewhere

The above instructions are for Postgres running inside docker, as the sample docker compose file does. There are myriad other ways to run Postgres, and the migration sequence then will depend on your exact setup.

Two common approaches are

1. Backup and restore, the pg_dumpall + psql import sequence described in Taking a backup above.

2. In place migrations using pg_upgrade, which is what the pgautoupgrade migration above does under the hood.

The first method, backup and restore, is low tech and will work similarly in most setups. The second method is more efficient, but requires a bit more careful preparation.

As another example, here is how one can migrate 12 to 15 when running Postgres on macOS, installed using Homebrew.

1. Stop your postgres. Make sure there are no more commands shown by ps aux | grep '[p]ostgres'.

2. Install postgres15.

3. Migrate data using pg_upgrade:

   /opt/homebrew/Cellar/postgresql@15/15.8/bin/pg_upgrade -b /opt/homebrew/Cellar/postgresql@12/12.18_1/bin -B /opt/homebrew/Cellar/postgresql@15/15.8/bin/ -d /opt/homebrew/var/postgresql@12 -D /opt/homebrew/var/postgresql@15

4. Start postgres 15 and verify version using SELECT VERSION().