README.md

Example Terraform Cloud agent from Packer image

Overview

This example showcases how to use Packer to pre-bake a Google VM Image with the necessary toolchain including Terraform Cloud agent and deploy this image using the tfc-agent-mig module.

We use startup script to register the runner when it comes online.

In this example, Packer creates a VM image that has the following:

• curl
• jq
• Terraform Cloud agent

Steps to deploy this example

1. Give Cloud Build Service Account necessary permissions to create a new GCE VM Image using Packer.

   # Export required variables
   export PROJECT_ID="your_gcp_project_id"
   export TFC_AGENT_VERSION="1.12.0"
   
   # GCP commands to enable services
   gcloud config set project $PROJECT_ID
   gcloud services enable compute.googleapis.com
   gcloud services enable cloudbuild.googleapis.com
   gcloud components update
   
   # Configure the Service Account for the Google Cloud Build
   export CLOUD_BUILD_ACCOUNT=$(gcloud projects get-iam-policy $PROJECT_ID --filter="(bindings.role:roles/cloudbuild.builds.builder)"  --flatten="bindings[].members" --format="value(bindings.members[])")
   
   gcloud projects add-iam-policy-binding $PROJECT_ID --member $CLOUD_BUILD_ACCOUNT --role roles/compute.instanceAdmin.v1
   
   gcloud projects add-iam-policy-binding $PROJECT_ID --member $CLOUD_BUILD_ACCOUNT --role roles/iam.serviceAccountUser

2. Build GCE VM image. When the build finishes, the image id of the form tfc-agent-image-* will be displayed. We will use this in the tfvars we create in the next step.

   gcloud builds submit --config=cloudbuild.yaml --substitutions=_TFC_AGENT_VERSION="$TFC_AGENT_VERSION"

3. Create terraform.tfvars file with the necessary values.

   project_id   = "your-project-id"
   tfc_org_name = "your-tfc-org-name"
   source_image = "image-name-from-prev-step"

4. Create the infrastructure

   terraform init
   terraform plan
   terraform apply

5. Your Terraform Cloud agents should become active at Organization Setting > Security > Agents.

6. Create additonal workspaces or use the existing workspace to run Terraform through the Terraform Cloud agent.Click here for more info on running the workspace.

Inputs

Name	Description	Type	Default	Required
project_id	The Google Cloud Platform project ID to deploy Terraform Cloud agent MIG	string	n/a	yes
source_image	Source disk image	string	n/a	yes
source_image_project	Project where the source image comes from	string	null	no
tfc_agent_pool_name	Terraform Cloud agent pool name to be created	string	"tfc-agent-mig-vm-packer-pool"	no
tfc_agent_pool_token_description	Terraform Cloud agent pool token description	string	"tfc-agent-mig-vm-packer-pool-token"	no
tfc_org_name	Terraform Cloud org name where the agent pool will be created	string	n/a	yes
tfc_project_name	Terraform Cloud project name to be created	string	"GCP agents"	no
tfc_workspace_name	Terraform Cloud workspace name to be created	string	"tfc-agent-mig-vm-packer"	no

Outputs

Name	Description
mig_instance_group	The instance group url of the created MIG
mig_instance_template	The name of the MIG Instance Template
mig_name	The name of the MIG
project_id	The Google Cloud Platform project ID to deploy Terraform Cloud agent MIG
service_account_email	Service account email for GCE used with the MIG template