formationai/terraform-provider-k8s

Kubernetes Terraform provider with support for raw manifests

Kubernetes Terraform Provider

The k8s Terraform provider enables Terraform to deploy Kubernetes resources. Unlike the official Kubernetes provider it handles raw manifests, leveraging kubectl directly to allow developers to work with any Kubernetes resource natively.

Usage

Use go get to install the provider:

go get -u github.com/ericchiang/terraform-provider-k8s

Register the plugin in ~/.terraformrc:

providers {
  k8s = "/$GOPATH/bin/terraform-provider-k8s"
}

The provider takes the following optional configuration parameters:

• If you have a kubeconfig available on the file system you can configure the provider as:

provider "k8s" {
  kubeconfig = "/path/to/kubeconfig"
}

• If you content of the kubeconfig is available in a variable, you can configure the provider as:

provider "k8s" {
  kubeconfig_content = "${var.kubeconfig}"
}

WARNING: Configuration from the variable will be recorded into a temporary file and the file will be removed as soon as call is completed. This may impact performance if the code runs on a shared system because and the global tempdir is used.

The k8s Terraform provider introduces a single Terraform resource, a k8s_manifest. The resource contains a content field, which contains a raw manifest.

variable "replicas" {
  type    = "string"
  default = 3
}

data "template_file" "nginx-deployment" {
  template = "${file("manifests/nginx-deployment.yaml")}"

  vars {
    replicas = "${var.replicas}"
  }
}

resource "k8s_manifest" "nginx-deployment" {
  content = "${data.template_file.nginx-deployment.rendered}"
}

In this case manifests/nginx-deployment.yaml is a templated deployment manifest.

apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: nginx-deployment
  labels:
    app: nginx
spec:
  replicas: ${replicas}
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80

The Kubernetes resources can then be managed through Terraform.

$ terraform apply
# ...
Apply complete! Resources: 1 added, 1 changed, 0 destroyed.
$ kubectl get deployments
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   3         3         3            3           1m
$ terraform apply -var 'replicas=5'
# ...
Apply complete! Resources: 0 added, 1 changed, 0 destroyed.
$ kubectl get deployments
NAME               DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
nginx-deployment   5         5         5            3           3m
$ terraform destroy -force
# ...
Destroy complete! Resources: 2 destroyed.
$ kubectl get deployments
No resources found.