Example Packer Config For building Windows On CircleCI

This folder contains everything you will need to build a Windows image with the CircleCI dsc resources, on CircleCI. For more information on setting up VM service, which includes specifying your new Windows image for your users, see our VM service guides for server v3.x and server v2.x.

Building a Windows Image to use with machine Executor

The following steps will guide you through building a Windows AMI, which you can then specify in the VM Service settings for your installation of CircleCI server, letting users of your installation run their builds in a Windows environment.

Please note that Windows images are built on CircleCI, so we suggest you run through this process once your installation is up and running. Alternatively you can use any other CircleCI account – including on our managed Cloud service.

Step-by-step guide

You can use either AWS or GCP to build your Windows machine image. Choose the one your server instance is running in.

For AWS

1. Prerequisites:

   1. Make sure that you have your own copy of this repository on your GitHub organization.

   2. Make sure that you have an access key for an AWS IAM User that has sufficient permission to create AMIs using Packer. Refer to documentation of Packer for details.

2. First, configure circleci-server-image-builder context that contains a required AWS access key as env vars. In the context, populate the env vars below:

   • AWS_ACCESS_KEY_ID (Access key ID of your access key)
   • AWS_SECRET_ACCESS_KEY (Secret access key of your access key)
   • AWS_DEFAULT_REGION (Region where your CircleCI server is hosted, e.g., us-east-1, us-west-1, ap-noartheast-1. Created AMI will be available only for this region.)

   Our official document would help you setting up contexts.

3. Create a new project on your CircleCI server to connect your own repo by clicking Set Up Project in the Add Projects page.

4. After project setup, the first build would run automatically. Wait for it to complete; it would take 2 - 3 hours to finish.

5. You will find your new Windows AMI ID at the end of the summarize results step in the job output.

For GCP

1. Prerequisites:

   1. Make sure that you have your own copy of this repository on your GitHub organization.

   2. Make sure that you have a JSON-formatted key for a GCP service account that has sufficient permission to create GCE images using Packer. Refer to documentation of Packer for details.

   3. Make sure that the default network for your working project (which is specified in CLOUDSDK_CORE_PROJECT as described below) has a firewall rule that allows ingress connections to TCP port 5986 of machines with a packer-winrm tag.

2. First, configure circleci-server-image-builder context that contains credentials for GCE as env vars. In the context, populate the env vars below:

   • GCLOUD_SERVICE_KEY (Base64-encoded service account key; the result of base64 -w 0 your-key-file.json)
   • GOOGLE_PROJECT_ID (Name of the project for which the image builder runs and the resulting image is saved)
   • GOOGLE_COMPUTE_ZONE (Zone where the image builder runs, e.g., us-central1-a, asia-northeast1-a.)

   Our official document would help you setting up contexts.

3. Create a new project on your CircleCI server to connect your own repo by clicking Set Up Project in the Add Projects page.

4. After project setup, the first build would run automatically. Wait for it to complete; it would take 2 - 3 hours to finish.

5. You will find your new Windows image ID at the end of the summarize results step in the job output.

Image Size

By default the disk image is set to 160 GB, but it can be updated based on your requirements. In the packer.yml, update the launch_block_device_mappings block for AWS and disk_size value for GCP

Common troubleshooting

• If you get any errors around not being able to find a default VPC, you will need to specify vpc_id, subnet_id (both for AWS) or subnetwork (for GCP) in windows/visual-studio/packer.yaml.

Ansible and Windows 2022

For Windows 2019 everything is configured using packer only. For Windows 2022 ansible is used for most of it. The base ansible repo is publicly available at https://github.com/CircleCI-Public/ansible and the branch you should use is test/install-vs-asadmin. If you need to modify the ansible playbook, you can fork this repo and modify that branch in your fork. Remember to update the repo URL within the build_image_ansible job. You can customize the image as you want by changing the ansible playbooks. There are some important configurations to check:

• User password: The password in the ansible task in the packer file must be the same there is in group_vars/windows_configure_vars.yml in the ansible repo
• Windows updates: There are some updates that can be rejected when running windows update, you can enable or disable this, or add your own updates to reject. This is in the file roles/windows/windows_updates/tasks/main.yml on ansible repo.

GC_OLD jobs

This jobs are commented by default, but you can uncomment if you prefer to run an scheduled validation for terminating packer instances.

What the packer job in this build does

• Sets up winrm.
• Adds scripts for removing winrm when we are ready to clean up.
• Copies over ImageHelpers and CircleDSCResources to the powershell module path.
• Runs some configuration to get the machine ready to use DSC and clean up some defaults that are not helpful.
• Runs DSC and restarts the machine a few times to let it continue through the configuration process.
• Runs Pester tests to validate that the image is configured correctly. These tests are designed to ensure that all of the software is actually callable not just “installed”.
• Copies: test results, the choco logs, and the software.md (a list of everything we install and test for the presence of) off of the host.
• Installs the SSH server and enables the cleanup script that runs on shutdown (check out the aws packer scripts for exactly how that works).
• Creates a Windows AMI.