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Upgrading PostgreSQL on Kubernetes

This guide walks you through upgrading PostgreSQL in your authentik Kubernetes deployment. The process requires a brief downtime period while the database is migrated.

note

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

Prerequisites​

  • kubectl access with permissions to scale deployments and exec into pods
  • Your existing values.yaml file used for authentik deployment
  • Basic understanding of Kubernetes and Helm commands

Overview of workflow​

The basic steps to upgrades PostgreSQL on Kubernetes are:

  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

Stop authentik services​

Begin by scaling down authentik services to prevent database access during the migration:

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

Back up the database​

Connect to your 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_DB > /bitnami/postgresql/dump.sql
tip

Consider copying the dump file to a safe location outside the pod:

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

This ensures you have a backup even if something goes wrong with the pod or storage.

Prepare the data directory​

While still connected to the PostgreSQL pod, prepare the data directory for the upgrade:

# 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 the old data directory immediately. Keeping it as data-old allows for recovery if the upgrade encounters issues.

Upgrade PostgreSQL​

Now update your values.yaml to specify the new PostgreSQL version:

postgresql:
    image:
        tag: <NEW_VERSION>

Apply these changes using Helm to deploy the updated configuration.

This will restart the PostgreSQL pod with the new image. When the pod starts, PostgreSQL will initialize a new, empty data directory since the previous directory was renamed.

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_DB < dump.sql

Restart authentik services​

After the database restoration completes successfully, restart authentik using Helm with your updated configuration.

This will scale your authentik server and worker deployments back to their original replica counts.

Troubleshooting​

If you encounter issues during the upgrade process:

  • 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 your dump file is missing after upgrading:

  • 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​

For persistent problems, you can restore from the data-old directory if needed:

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.