This guide will walk you through the steps to integrate MongoDB into your existing Helm chart for your Kubernetes application. By adding MongoDB, you can leverage its capabilities for NoSQL database management. We will use the Bitnami MongoDB Helm chart as a dependency and configure it accordingly.

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Prerequisites

  • Helm installed and configured
  • Kubernetes cluster up and running
  • Existing Helm chart for your application

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Steps to Integrate MongoDB

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1. Add MongoDB Helm Repository

First, add the Bitnami repository, which hosts the MongoDB Helm chart,

helm repo add bitnami https://charts.bitnami.com/bitnami
helm repo update

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2. Update Chart.yaml

Open your existing Helm chart directory and edit the Chart.yaml file to add MongoDB as a dependency,

Chart.yaml
apiVersion: v2
name: your-app
description: A Helm chart for your Kubernetes application
version: 0.1.0
appVersion: '1.0'

dependencies:
  - name: mongodb
    version: 13.10.3
    repository: https://charts.bitnami.com/bitnami

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3. Update values.yaml

Create or update the values.yaml file to include configuration values for MongoDB. Customize the values as per your requirements.

values.yaml
mongodb:
  enabled: true
  auth:
    rootPassword: myrootpassword
    username: myuser
    password: mypassword
    database: mydatabase
  primary:
    persistence:
      enabled: true
      size: 50Gi

Over-provisioning on disk size (primary.persistence.size) isn’t a bad idea considering that disks are cheap in any cloud. It is also slightly trickier to increase volume sizes at later point in time due to some Kubernetes limitations. So we recommend you pick a good number here from the start.

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4. Install/Update Dependencies

Navigate to your Helm chart directory and run the following command to update dependencies,

helm dependency update

This command will download the MongoDB chart and add it to your charts/ directory.

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5. Update Your Application Deployment

Modify your application’s deployment files to include the MongoDB service. Ensure your application can connect to MongoDB using the service name and credentials specified in the values.yaml file.

For example, if using a ConfigMap to store environment variables for your application, you might update it like this,

templates/configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: your-app-config
data:
  DATABASE_HOST: 'your-app-mongodb'
  DATABASE_PORT: '27017'
  DATABASE_USER: 'myuser'
  DATABASE_PASSWORD: 'mypassword'
  DATABASE_NAME: 'mydatabase'

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6. Deploy Your Application

Finally, deploy or upgrade your application using Helm,

helm install your-app ./your-app-chart
# or if upgrading an existing release
helm upgrade your-app ./your-app-chart

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7. Verify Deployment

Check the status of your Helm release to ensure everything is running correctly,

helm status your-app

Also, verify that the MongoDB pod is running,

kubectl get pods

You should see a pod for MongoDB, something like your-app-mongodb-0.

Congratulations! You have successfully added MongoDB to your existing Helm chart. 🚀

This integration allows your application to use MongoDB for NoSQL database management, managed efficiently with Helm. Customize the MongoDB configuration further by modifying the values.yaml file as needed.

For more detailed configurations and advanced settings, refer to the Bitnami MongoDB Helm chart documentation.