Using Goss to validate Packer builds

Ever wanted to validate your Packer image with Goss? Well, you can!

I was looking into ways to make sure that the image I just provisioned with Packer and Chef is working as expected. After some research, I found Goss, which is a tool to validate servers.

So, I just needed to glue all that together.

Lucky me, there is a Packer plugin for that, made by the folks at Yale.

I found some issues within the plugin, so I fixed them in my own fork, though I have high hopes that they will accept my suggestions soon.

You can download the binary from the releases page and save it as ~/.packer.d/plugins/packer-provisioner-goss with 0755 permissions.

The usage is very simple, jsut add a goss provisioner to your Packer build:

{
  "builders": [
    {
      "type": "googlecompute",
      "project_id": "foo",
      "zone": "us-west2-b",
      "machine_type": "n1-standard-2",
      "preemptible": true,
      "ssh_username": "ubuntu",
      "source_image_family": "ubuntu-1804-lts"
    }
  ],
  "provisioners": [
    {
      "type": "chef-solo",
      "version": "14.7.17",
      "cookbook_paths": [
        "cookbooks"
      ],
      "chef_environment": "myenv",
      "data_bags_path": "data_bags/myenv",
      "environments_path": "environments",
      "roles_path": "roles/myenv",
      "run_list": [
        "role[foo]"
      ]
    },
    {
      "type": "goss",
      "retry_timeout": "5m",
      "sleep": "5s",
      "tests": [
        "goss/goss.yml"
      ]
    }
  ]
}

The goss/goss.yml is a regular Goss test suite file.

And thats it. Run packer build and it will run everything and check it with Goss before pushing the image to Google Cloud (in this example).

Very simple and quick tip, but I found it really useful and I hope you enjoy it!