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Upgrading PostgreSQL on Kubernetes

This guide walks through a manual PostgreSQL major-version upgrade for an authentik Kubernetes deployment. The process requires downtime while the database is exported, recreated, and restored.

info

For this guide, we assume the PostgreSQL pod is named authentik-postgresql-0, which is the default name in the authentik Helm chart.

Before you start​

  • kubectl access with permissions to scale deployments and exec into pods
  • the values.yaml file used for your authentik deployment
  • enough storage for a SQL dump and a copy of the old database files
  • a maintenance window long enough to export and restore the database

Review Backup and restore before proceeding.

Overview​

The upgrade flow is:

  1. Stop authentik services
  2. Back up the database
  3. Prepare the data directory
  4. Upgrade PostgreSQL
  5. Restore database content
  6. Restart authentik services

1. Stop authentik services​

Scale down authentik so nothing writes to PostgreSQL during the upgrade:

kubectl scale deploy --replicas 0 authentik-server
kubectl scale deploy --replicas 0 authentik-worker

2. Back up the database​

Connect to the PostgreSQL pod:

kubectl exec -it authentik-postgresql-0 -- bash

After you are connected, execute these commands to create a database backup:

# Navigate to the PostgreSQL data directory
cd /bitnami/postgresql/

# Set the PostgreSQL password from environment variable
export PGPASSWORD=$(cat $POSTGRES_PASSWORD_FILE)

# Create a full database dump
pg_dump -U $POSTGRES_USER $POSTGRES_DATABASE > /bitnami/postgresql/dump.sql
tip

Copy the dump file out of the pod before continuing:

# From a separate terminal
kubectl cp authentik-postgresql-0:/bitnami/postgresql/dump.sql ./authentik-db-backup.sql

Keeping an external copy protects you if the pod or persistent volume is recreated unexpectedly.

3. Prepare the data directory​

While still connected to the pod, prepare the data directory:

# Ensure you're in the PostgreSQL data directory
cd /bitnami/postgresql/

# Verify the SQL dump exists and has content
ls -lh dump.sql

# Preserve the existing data by renaming the directory
mv data data-old
caution

Do not delete data-old yet. It provides a rollback path if the restore fails.

4. Upgrade PostgreSQL​

Update values.yaml with the new PostgreSQL image tag:

postgresql:
    image:
        tag: <NEW_VERSION>

Apply the change with Helm using your normal deployment command.

When the pod restarts with the new image, PostgreSQL initializes a new empty data directory because the previous one was renamed to data-old.

5. Restore database content​

Connect to the PostgreSQL pod again:

kubectl exec -it authentik-postgresql-0 -- bash

Restore your database from the backup:

# Navigate to the PostgreSQL directory
cd /bitnami/postgresql/

# Verify your dump file is still there
ls -lh dump.sql

# Set the PostgreSQL password
export PGPASSWORD=$(cat $POSTGRES_PASSWORD_FILE)

# Import the database dump
psql -U $POSTGRES_USER $POSTGRES_DATABASE < dump.sql

6. Restart authentik services​

After the restore completes successfully, scale authentik back up or re-run your Helm deployment so the server and worker return to their normal replica counts.

7. Verify the upgrade​

After everything starts again:

  • confirm the PostgreSQL pod is healthy
  • check the PostgreSQL, server, and worker logs for startup or migration errors
  • log in to authentik through the UI to verify the application is functioning normally

Troubleshooting​

If something goes wrong during the upgrade:

  • Check PostgreSQL logs: 
    kubectl logs authentik-postgresql-0
  • Verify the values in your values.yaml file match the recommended settings
  • Ensure you have sufficient storage available for both the database dump and the database itself

Dump file not found​

If dump.sql is missing after the restart:

  • You may need to restore from the external backup if you copied it out of the pod
  • The volume might have been recreated if you're using ephemeral storage

Restoring the original database​

If you need to roll back to the old PostgreSQL data directory:

kubectl exec -it authentik-postgresql-0 -- bash
cd /bitnami/postgresql/
mv data data-new-failed
mv data-old data

Then restart PostgreSQL with the original version in your values.yaml.