packer-cn/website/source/docs/builders/googlecompute.markdown

layout	page_title	description
docs	Google Compute Builder	The `googlecompute` Packer builder is able to create images for use with Google Compute Engine (GCE) based on existing images. Google Compute Engine doesn't allow the creation of images from scratch.

Google Compute Builder

Type: googlecompute

The googlecompute Packer builder is able to create images for use with Google Compute Engine(GCE) based on existing images. Google Compute Engine doesn't allow the creation of images from scratch.

Authentication

Authenticating with Google Cloud services requires at most one JSON file, called the account file. The account file is not required if you are running the googlecompute Packer builder from a GCE instance with a properly-configured Compute Engine Service Account.

Running With a Compute Engine Service Account

If you run the googlecompute Packer builder from a GCE instance, you can configure that instance to use a Compute Engine Service Account. This will allow Packer to authenticate to Google Cloud without having to bake in a separate credential/authentication file.

To create a GCE instance that uses a service account, provide the required scopes when launching the instance.

For gcloud, do this via the --scopes parameter:

gcloud compute --project YOUR_PROJECT instances create "INSTANCE-NAME" ... \
               --scopes "https://www.googleapis.com/auth/compute" \
                        "https://www.googleapis.com/auth/devstorage.full_control" \
               ...

For the Google Developers Console:

1. Choose "Show advanced options"
2. Tick "Enable Compute Engine service account"
3. Choose "Read Write" for Compute
4. Chose "Full" for "Storage"

The service account will be used automatically by Packer as long as there is no account file specified in the Packer configuration file.

Running Without a Compute Engine Service Account

The Google Developers Console allows you to create and download a credential file that will let you use the googlecompute Packer builder anywhere. To make the process more straightforwarded, it is documented here.

1. Log into the Google Developers Console and select a project.

2. Under the "APIs & Auth" section, click "Credentials."

3. Click the "Create new Client ID" button, select "Service account", and click "Create Client ID"

4. Click "Generate new JSON key" for the Service Account you just created. A JSON file will be downloaded automatically. This is your account file.

Basic Example

Below is a fully functioning example. It doesn't do anything useful, since no provisioners are defined, but it will effectively repackage an existing GCE image. The account file is obtained in the previous section.

{
  "type": "googlecompute",
  "account_file": "account.json",
  "project_id": "my-project",
  "source_image": "debian-7-wheezy-v20150127",
  "zone": "us-central1-a"
}

Configuration Reference

Configuration options are organized below into two categories: required and optional. Within each category, the available options are alphabetized and described.

In addition to the options listed here, a communicator can be configured for this builder.

Required:

• project_id (string) - The project ID that will be used to launch instances and store images.

• source_image (string) - The source image to use to create the new image from. Example: "debian-7-wheezy-v20150127"

• zone (string) - The zone in which to launch the instance used to create the image. Example: "us-central1-a"

Optional:

• account_file (string) - The JSON file containing your account credentials. Not required if you run Packer on a GCE instance with a service account. Instructions for creating file or using service accounts are above.

• disk_size (integer) - The size of the disk in GB. This defaults to 10, which is 10GB.

• image_name (string) - The unique name of the resulting image. Defaults to "packer-{{timestamp}}".

• image_description (string) - The description of the resulting image.

• instance_name (string) - A name to give the launched instance. Beware that this must be unique. Defaults to "packer-{{uuid}}".

• machine_type (string) - The machine type. Defaults to "n1-standard-1".

• metadata (object of key/value strings)

• network (string) - The Google Compute network to use for the launched instance. Defaults to "default".

• state_timeout (string) - The time to wait for instance state changes. Defaults to "5m".

• tags (array of strings)

Gotchas

Centos images have root ssh access disabled by default. Set ssh_username to any user, which will be created by packer with sudo access.

The machine type must have a scratch disk, which means you can't use an f1-micro or g1-small to build images.