DevOps 3: Managing Microservices with Helm
As we dive deeper into our journey of building a scalable microservices architecture on Amazon EKS, we encounter the challenge of managing multiple microservices and their deployments efficiently. This is where Helm, the Kubernetes package manager, becomes invaluable. Helm simplifies the deployment process by encapsulating Kubernetes manifests into charts, making application management on Kubernetes environments as simple as managing packages on traditional operating systems.
Why Helm?
Helm introduces a higher level of abstraction for managing Kubernetes applications. It allows developers and operators to package, configure, and deploy applications onto Kubernetes clusters in a consistent manner. This efficiency is crucial when dealing with microservices that have complex dependencies and configurations.
- Version Control for Deployments: Helm charts can be versioned and stored in a chart repository, allowing for controlled releases and rollbacks.
- Simplified Management: Helm consolidates all Kubernetes resource files for an application into a single chart, simplifying updates and customizations.
- Environment Consistency: Helm charts support templating, which allows for easy replication of application deployments across different environments.
Getting Started with Helm
Before deploying our microservices, we need to install Helm and configure it to work with our EKS cluster.
Step 1: Install Helm
Follow the instructions on the Helm documentation to install Helm on your workstation. Helm provides binary releases for Windows, macOS, and Linux.
Step 2: Initialize Helm and Add Repositories
Once installed, you can initialize Helm’s local environment and add chart repositories. For example, to add the stable Helm charts repository:
helm repo add stable https://charts.helm.sh/stable
helm repo update
Deploying a Microservice with Helm
For this demonstration, let’s deploy a simple “Hello World” web application as our microservice.
Step 1: Create a Helm Chart
First, create a Helm chart for our microservice. Navigate to your project directory and run:
helm create hello-world
This command creates a new directory named hello-world
with the scaffolding for a Helm chart.
Step 2: Customize the Chart for Your Microservice
Navigate into the hello-world
directory. You’ll find several files and folders, including the values.yaml
file, which is where you define values to pass into your chart templates.
Edit the values.yaml
file to specify the image and service type for your “Hello World” application:
image:
repository: <your-hello-world-image>
tag: latest
pullPolicy: IfNotPresent
service:
type: LoadBalancer
port: 80
Replace <your-hello-world-image>
with the Docker image repository for your application.
Step 3: Deploy the Microservice
Deploy your microservice using Helm:
helm install hello-world-release ./hello-world
This command deploys your “Hello World” application onto the EKS cluster, creating a new release named hello-world-release
.
Step 4: Verify the Deployment
Check the status of your Helm release to ensure the deployment was successful:
helm status hello-world-release
Additionally, since we’ve used a LoadBalancer
service type, you can retrieve the external IP or hostname to access your application:
kubectl get service hello-world-release
Conclusion
Helm has enabled us to package and deploy our “Hello World” microservice onto our EKS cluster effortlessly. This streamlined process not only simplifies the deployment of individual services but also ensures consistency and reliability across our microservices architecture.
Gotchas and Tips
- Chart Dependencies: If your microservice depends on external services (e.g., databases), use Helm’s dependency management features to handle these dependencies.
- Helm Chart Best Practices: Familiarize yourself with Helm chart best practices to ensure your charts are maintainable and secure.
- Release Management: Take advantage of Helm’s release management features to roll back deployments or manage multiple versions of your application.
With Helm in our toolkit, we’re well-equipped to manage the complexity of deploying and managing microservices on Kubernetes. As we continue this series, we’ll explore more advanced topics to enhance our cloud-native infrastructure on Amazon EKS.