Deploy Consul and Vault on Kubernetes with run triggers

With HCP Terraform and Terraform Enterprise, you can connect workspaces to each other with a feature called "run triggers". After a successful apply in a source workspace, a run trigger will automatically queue a run in the connected workspace. Run triggers are designed for workspaces that rely on information or infrastructure produced by other workspaces.

In this tutorial, you will accomplish three things using HCP Terraform run triggers:

1. Deploy a Kubernetes cluster on Google Cloud.
2. Deploy Consul on the Kubernetes cluster using a Helm chart
3. Deploy Vault (configured to use a Consul backend) on the Kubernetes cluster using a Helm chart.

This tutorial highlights Terraform and HCP Terraform best practices for code management and modules.

The example configuration uses modules and organizes Terraform configuration for each resource (Kubernetes, Consul, and Vault) in separate repositories. First, you will create and configure HCP Terraform workspaces for each resource, then link them together using run triggers.

The configuration defines a Kubernetes cluster with 3 nodes and uses the Consul and Vault run triggers to deploy Consul and Vault.

Prerequisites

This tutorial assumes that you are familiar with the standard Terraform workflow, HCP Terraform, run triggers and provisioning a Kubernetes cluster using Terraform.

If you are unfamiliar with any of these topics, reference their respective tutorials.

• Terraform Workflow — All Get Started tutorials
• HCP Terraform — All Get Started with HCP Terraform tutorials
• Run Triggers — Connect Workspaces with Run Triggers
• Provision GKE cluster using Terraform — Provision a GKE Cluster (Google Cloud)

For this tutorial, you will need:

1. an HCP Terraform or Terraform Enterprise account
2. a Google Cloud account with access to Compute Admin and Kubernetes Engine Admin
3. a GitHub account

If you don't have your GCP credentials as a JSON or your credentials don't have access to Compute Admin and Kubernetes Engine Admin, reference the GCP Documentation to generate a new service account and with the right permissions.

If you are using a Google Cloud service account, your account must be assigned the Service Account User role.

Create Kubernetes workspace

Fork the Learn Terraform Pipelines K8s repository.

Then, create a VCS-driven HCP Terraform workspace connected to your forked repository. HCP Terraform will confirm that the workspace configuration uploaded successfully.

Configure variables

After creating your workspace, HCP Terraform prompts you to set the google_project variable. Set this to the ID of your Google Project, which you can find in your Google Cloud Platform console.

Click Save variables.

The configuration also contains two input variables, configured with defaults.

• region — GCP region to deploy clusters
  This defaults to us-central1. For a full list of GCP regions, refer to Google's Region and Zones documentation.
• cluster_name — Name of Kubernetes cluster
  This defaults to tfc-pipelines.

HCP Terraform will use these variable values to configure and deploy your Kubernetes cluster. Terraform will create outputs for the Kubernetes credentials, which other workspaces can then consume. Review the output definitions in [outputs.tf].(https://github.com/hashicorp-education/learn-terraform-pipelines-k8s/blob/main/outputs.tf)

Create Consul workspace

Fork the Learn Terraform Pipelines Consul repository.

The main.tf file contains providers for Kubernetes and Helm as well as the Terraform tfe_outputs data source to retrieve values from your Kubernetes workspace.

Create an HCP Terraform workspace connected to your forked repository. HCP Terraform will confirm that the configuration uploaded successfully.

Configure variables

Click on Configure variables then specify the variables required for this deployment.

• cluster_workspace — Workspace that manages the Kubernetes cluster. If you did not customize the workspace name in the previous step, use learn-terraform-pipelines-k8s.
• organization - HCP Terraform organization that contains your Kubernetes workspace.

Click Save variables, then click Go to workspace overview to view your workspace.

Enable run trigger

Click on Settings ,then select Run Triggers.

Under Source Workspaces, select your Kubernetes workspace (learn-terraform-pipelines-k8s) then click Add Workspace.

The run trigger will now kick off runs in this workspace after successful runs in the Kubernetes workspace. The configuration in this workspace consumes the Kubernetes credentials outputs from the Kubernetes workspace to authenticate to the Kubernetes and Helm provider.

Create Vault workspace

Fork the Learn Terraform Pipelines Vault repository.

The main.tf file contains providers for Kubernetes and Helm as well as the Terraform tfe_outputs data source to retrieve values from your Kubernetes and Consul workspaces.

Create an HCP Terraform workspace connected to your forked repository. HCP Terraform will confirm that the configuration uploaded successfully.

Configure variables

Click on Configure variables, then set the configuration's required variables.

• consul_workspace - HCP Terraform Workspace for the Consul cluster. If you did not customize the workspace name in the previous step, use learn-terraform-pipelines-consul.
• cluster_workspace — HCP Terraform Workspace for the Kubernetes cluster. If you did not customize your workspace name, this is learn-terraform-pipelines-k8s.
• organization — Organization of workspace that created the Kubernetes cluster Set this to your HCP Terraform Organization.

Click Save variables, then click Go to workspace overview to view your workspace.

Enable run trigger

Click on Settings then select Run Triggers.

Under Source Workspaces, select your Consul workspace (learn-terraform-pipelines-consul) then click Add Workspace.

The run trigger will now kick off runs in this workspace after successful runs in the Consul workspace. The configuration in this workspace consumes the Kubernetes credentials outputs from the Kubernetes workspace to authenticate to the Kubernetes and Helm provider. It also retrieves the Helm release name and Kubernetes namespace from the Consul workspace.

Allow remote state access

HCP Terraform protects your state file by encrypting it at rest and automatically restricting access to it from other workspaces. You must explicitly enable state sharing between workspaces.

Navigate to the learn-terraform-pipelines-k8s workspace's Settings. Under General Settings, scroll to the Remote state sharing section.

Under Search for workspaces to share with select learn-terraform-pipelines-consul and learn-terraform-pipelines-vault from the drop-down menu. Then click Save settings.

Now allow the Vault workspace to access the Consul workspace's state. Navigate to the learn-terraform-pipelines-consul workspace's General Settings, then scroll to the Remote state sharing section. Under Search for workspaces to share with select learn-terraform-pipelines-vault from the dropdown menu, then click Save settings.

Create variable set

The workspaces in this tutorial need your GCP credentials to authenticate the provider. Instead of creating the same variable with your credentials in each workspace, you can use a variable set that applies to multiple workspaces.

Open your HCP Terraform organization settings, click Variable sets, then click Create variable set. Name your variable set Google Credentials.

Under Workspaces, choose the option to Apply to specific workspaces. In the dropdown below, add the this tutorial's three workspaces. If you have not changed the names, they are:

• learn-terraform-pipelines-k8s
• learn-terraform-pipelines-consul
• learn-terraform-pipelines-vault

Use jq to remove the newlines from your JSON credentials file.

$ cat <key file>.json | jq -c

Next, add your credentials to the variable set by clicking + Add variable. Create a variable named GOOGLE_CREDENTIALS and set the value to your formatted GCP JSON credentials. Select Environment variable as the category, mark the variable as Sensitive, and click Save variable.

Click Create variable set.

Deploy Kubernetes cluster

Now that you have successfully configured all three workspaces (Kubernetes, Consul, and Vault), you can deploy your Kubernetes cluster.

Select your learn-terraform-pipelines-k8s workspace, click the Actions dropdown, then click Start new run.

Notice HCP Terraform automatically queues a plan for the learn-terraform-pipelines-consul workspace after this run completes.

Click Confirm & Apply to apply this configuration. This process should take about 10 minutes to complete.

Once the apply completes, verify your Kubernetes cluster by visiting the GKE Console Page. Your Kubernetes cluster should only have three nodes and no workloads.

Deploy Consul

Navigate to the learn-terraform-pipelines-consul workspace, view the run plan, and click Confirm & Apply to deploy Consul onto your cluster using the Helm provider. The plan retrieves the Kubernetes cluster authentication information from the Kubernetes workspace to configure both the Kubernetes and Helm provider.

This process will take about 2 minutes to complete.

Notice that HCP Terraform automatically queues a plan for the learn-terraform-pipelines-vault workspace after this apply completes.

Deploy Vault

Navigate to the learn-terraform-pipelines-vault workspace, view the run plan, then click Confirm & Apply to deploy Vault onto your cluster using the Helm provider and configure it to use Consul as the backend. The plan retrieves the Kubernetes namespace from the Consul workspace's remote state and deploys Vault to the same workspace.

This process will take about 2 minutes to complete.

Verify Consul and Vault deployments

Once the apply completes, verify by visiting the GKE Console. Your Kubernetes cluster should also have 3 nodes. Navigate to Workloads to confirm the Consul and Vault deployments.

Notice that the Vault pods have warnings because Vault is sealed. You will have the option to unseal Vault and resolve the warnings once you enable port forwarding.

Verify that Consul and Vault have both been deployed by viewing their respective dashboard.

First, activate your Cloud Shell (button on top right).

Run the following command in Cloud Shell to configure access to your Kubernetes cluster. If you did not use the default values, replace tfc-pipelines with your Kubernetes cluster name, us-central1-a with your zone.

$ gcloud container clusters get-credentials tfc-pipelines --zone us-central1-a

$ kubectl port-forward -n hashicorp-learn consul-server-0 8080:8500

$ kubectl port-forward -n hashicorp-learn hashicorp-learn-vault-0 8081:8200

Congratulations — you have successfully completed the tutorial and applied some HCP Terraform best practices. By keeping your infrastructure configuration modular and integrating workspaces together using run triggers, your Terraform configuration becomes extensible and easier to understand.

Clean up resources

To clean up the resources and destroy the infrastructure you have provisioned in this tutorial, go to each workspace in the reverse order you created them in, queue a destroy plan, and apply it. Then, delete the workspace from HCP Terraform. Destroy and delete your workspaces in the following order:

1. Vault workspace
2. Consul workspace
3. Kubernetes workspace

For a more detailed tutorial on destroying resources on HCP Terraform, reference the Clean up Cloud Resources tutorial.

Next steps

To watch a video of a demo similar to this tutorial, reference the Infrastructure Pipelines with HCP Terraform webinar.

To learn how to get started with Consul Service Mesh, visit the Getting Started with Consul Service Mesh Learn track.

To learn how to leverage Vault features on Kubernetes, visit the Kubernetes Vault tutorials.

To learn how to use the TFE provider to deploy the HCP Terraform resources used in this guide, visit the Use the TFE Provider to Manage HCP Terraform Workspaces tutorial.