Day 9: Advanced Terraform – Managing Kubernetes Resources

Welcome to Day 9 of the Zero to Platform Engineer in 30 Days challenge! 🚀 Today, we’re diving deeper into Terraform, exploring advanced features like modules, workspaces, and how to manage Kubernetes resources programmatically

Why Use Terraform for Kubernetes

Terraform isn’t just for managing cloud infrastructure. It’s also a powerful tool for managing Kubernetes resources like:

Namespaces
Deployments
Services
Ingress rules
ConfigMaps and Secrets

Using Terraform to manage Kubernetes ensures that your infrastructure and workloads are defined in code, version-controlled, and easily reproducible.

Advanced Terraform Concepts

1. Modules

Modules are reusable pieces of Terraform configuration. They help you:

Avoid repetition.
Create consistent resource configurations.
Share configurations across projects.

🎯 Example Module Structure:

modules/
  nginx/
    main.tf
    variables.tf
    outputs.tf

2. Workspaces

Workspaces allow you to manage multiple Terraform configurations in the same repository.

Create a workspace:

terraform workspace new dev

Switch to a workspace:

terraform workspace select dev

Dynamic Blocks:

Dynamic blocks let you create multiple similar resources programmatically.

resource "aws_security_group" "example" {
  name = "example"

  dynamic "ingress" {
    for_each = var.ingress_rules
    content {
      from_port   = ingress.value.from_port
      to_port     = ingress.value.to_port
      protocol    = ingress.value.protocol
      cidr_blocks = ingress.value.cidr_blocks
    }
  }
}

Managing Kubernetes with Terraform

Terraform can be used to manage Kubernetes resources, including:

Namespaces
Deployments
Services
Ingress rules
ConfigMaps and Secrets

Let’s explore how to use Terraform to manage Kubernetes resources.

Step 1: Create a Terraform Configuration File

Add the Kubernetes provider to your Terraform configuration:

provider "kubernetes" {
  config_path = "~/.kube/config"
}

Initialize Terraform:

terraform init

Step 2: Create Kubernetes Resources

Define a namespace:

resource "kubernetes_namespace" "zero-to-platform-engineer" {
  metadata {
    name = "zero-to-platform-engineer"
  }
}

Define a deployment:

resource "kubernetes_deployment" "nginx" {
  metadata {
    name      = "nginx"
    namespace = kubernetes_namespace.example.metadata[0].name
  }

  spec {
    replicas = 3

    selector {
      match_labels = {
        app = "nginx"
      }
    }

    template {
      metadata {
        labels = {
          app = "nginx"
        }
      }

      spec {
        container {
          image = "nginx:1.21"
          name  = "nginx"

          port {
            container_port = 80
          }
        }
      }
    }
  }
}

Define a service:

resource "kubernetes_service" "nginx" {
  metadata {
    name      = "nginx-service"
    namespace = kubernetes_namespace.example.metadata[0].name
  }

  spec {
    selector = {
      app = "nginx"
    }

    port {
      port        = 80
      target_port = 80
    }

    type = "ClusterIP"
  }
}

Step 3: Apply the Configuration

Run terraform plan to preview the changes:

terraform plan

Apply the changes:

terraform apply

Verify the resources in Kubernetes:

kubectl get all -n zero-to-platform-engineer

Step 4: Destroy Resources

When you’re done, clean up the resources:

terraform destroy

Challenges for Today

Create a module to manage Kubernetes namespaces, deployments, and services.
Use workspaces to manage different environments (e.g., dev, staging, prod).
Deploy a containerized application using Terraform.

What’s Next?

Tomorrow, we’ll continue exploring advanced workflows by diving into Helm and its integration with Terraform to manage Kubernetes applications even more efficiently.

Get ready to level up your platform engineering skills! 🚀

👉 Check it out here: Zero to Platform Engineer Repository

Feel free to clone the repo, experiment with the code, and even contribute if you’d like! 🚀

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