Installing PostgreSQL in Kubernetes with Bitnami's Helm Chart

PostgreSQL is one of the most popular and reliable open-source relational database systems available today.

When running it in a Kubernetes environment, the Bitnami Helm chart is a top choice.

This guide will walk you through the setup process and how I have deployed Postgres in my Homelab Kubernetes cluster.

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Step 1: Create Kubernetes Secrets for Database Credentials

First, we need to securely store our database passwords as Kubernetes secrets. This prevents passwords from being exposed in configuration files or deployment manifests.

kubectl create secret generic postgres-credentials -n database \
  --from-literal=POSTGRES_PASSWORD='AdminPassword' \
  --from-literal=APP_DB_PASSWORD='AUserPassword'

Note: Replace ‘AdminPassword’ and ‘AUserPassword’ with secure passwords of your own.

Step 2: Prepare Storage on Worker Node

PostgreSQL requires persistent storage to maintain your data across pod restarts and redeployments.

I have one master node and one worker node, so for this guide, I’ll use host path volumes on our worker node.

Create the Required Directories

sudo mkdir -p /data/postgres-data /data/postgres-dump

Set Correct Ownership for the Bitnami PostgreSQL User (UID 1001)

sudo chown -R 1001:1001 /data/postgres-data
sudo chown -R 1001:1001 /data/postgres-dump

Configure Appropriate Permissions

sudo chmod -R 750 /data/postgres-data
sudo chmod -R 750 /data/postgres-dump

Step 3: Create Persistent Volumes

Create a file named postgres-pv.yaml with the following persistent volume definitions.

apiVersion: v1
kind: PersistentVolume
metadata:
  name: postgres-data-pv
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  claimRef:
    namespace: database
    name: data-postgres-postgresql-0
  hostPath:
    path: /data/postgres-data
    type: DirectoryOrCreate
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: postgres-dump-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  claimRef:
    namespace: database
    name: postgres-postgresql-pgdumpall
  hostPath:
    path: /data/postgres-dump
    type: DirectoryOrCreate

then apply it to your cluster:

kubectl create -f postgres-pv.yaml

Important: Your postgres-pv.yaml should define appropriate persistent volumes that point to the directories created in step 2, with the correct storage class and access modes. Be sure to tweak as needed.

Step 4: Deploy PostgreSQL with Helm

Now we’re ready to install PostgreSQL using the Bitnami Helm chart. Create a custom postgres-values.yaml file with the following configuration preferences (again tweak as necessary).

auth:
  existingSecret: postgres-credentials
  secretKeys:
    adminPasswordKey: POSTGRES_PASSWORD
    userPasswordKey: APP_DB_PASSWORD

primary:
  persistence:
    storageClass: "local-storage"
    size: 10Gi
    accessModes:
      - ReadWriteOnce
    annotations: {}
    
service:
  type: ClusterIP
  ports:
    postgresql: 5432

# Backup and monitoring options
backup:
  enabled: true
  cronjob:
    schedule: "0 2 * * *"  # Daily backup at 2 AM

Then run:

helm install postgres oci://registry-1.docker.io/bitnamicharts/postgresql -n database --values postgres-values.yaml

The Helm chart will create all necessary resources.

Step 5: Database Administration and Configuration

Once PostgreSQL is running, you can connect to it for administrative tasks.

Access the PostgreSQL Pod

kubectl exec -it -n database postgres-postgresql-0 -- /opt/bitnami/scripts/postgresql/entrypoint.sh /bin/bash

Log in to PostgreSQL

psql -U postgres

When prompted, enter the admin password you specified in step 1.

Common Database Administration Tasks

Here are some typicsl administrative tasks you may want to perform at this point:

Create a New Database

CREATE DATABASE homelabdb;

Create a Database User

CREATE USER myuser WITH PASSWORD 'your-password';

Grant Privileges

GRANT ALL PRIVILEGES ON DATABASE homelabdb TO myuser;
GRANT ALL PRIVILEGES ON SCHEMA public TO myuser;
GRANT ALL PRIVILEGES ON ALL TABLES IN SCHEMA public TO myuser;

Create a Table

CREATE TABLE daily_steps (
    id SERIAL PRIMARY KEY,
    date DATE UNIQUE NOT NULL,
    steps INTEGER NOT NULL,
    created_at TIMESTAMP WITH TIME ZONE DEFAULT CURRENT_TIMESTAMP
);

Change Object Ownership

-- Connect to the specific database
\c homelabdb postgres

-- Change table ownership
ALTER TABLE daily_steps OWNER TO travis;

-- Grant all privileges explicitly
GRANT ALL PRIVILEGES ON TABLE daily_steps TO travis;
GRANT ALL PRIVILEGES ON SCHEMA public TO travis;

Verify Permissions

\z daily_steps

Conclusion

You now have a fully functional PostgreSQL database running in your Kubernetes cluster. This setup provides the foundation for deploying stateful applications that require relational database storage.

For production environments, consider implementing:

Regular database backups
High availability configurations
Monitoring and alerting
Resource limits and requests tuning

The Bitnami PostgreSQL Helm chart offers many additional configuration options through its values file, allowing you to customize the deployment to your specific needs.