Packer Builds for Multiple Azure Tenants

[straubt1]

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Description

Situation: Building multiple images in different Azure Tenants and publishing to a single HCP Packer Bucket. In order to do this, we must create a single .pkr.hcl file and execute a single packer build .. After a successful build, we have a need to tag the underlying images after a successful Wiz scan.

High Level Order:

• packer build . for several concurrent image builds, each isolated in their own Azure Tenant.
• Images are successfully built, image id's are present in the manifest.json file.
• Security scan on each image.
• Image scan on each image is successful.
• Tag the underling images, which requires the Tenant Id and Subscription Id for authentication.

Current: The Azure Packer plugin (https://github.com/hashicorp/packer-plugin-azure) currently exposing a single Build variable -> https://developer.hashicorp.com/packer/integrations/hashicorp/azure/latest/components/builder/arm#build-shared-information-variables called "SourceImageName".

Proposal: The Azure Packer plugin should expose tenant (and optionally subscription) id to allow custom_data to contain this information for post build tasks.

Ideal Syntax:

post-processor "manifest" {
    output     = "manifest.json"
    strip_path = true
    custom_data = {
      tenant_id       = build.TenantID
      subscription_id = build.SubsriptionID # optional, could be parsed from "artifact_id" but very help here
    }
  }

Would result in:

{
  "builds": [
    {
      "name": "tenant01",
      "builder_type": "azure-arm",
      "build_time": 1724179638,
      "files": null,
      "artifact_id": "/subscriptions/{AZ_SUBSCRIPTION_ID}/resourceGroups/packer-build-images/providers/Microsoft.Compute/images/azure_ubuntu-2204_sigtenant1_0.0.26",
      "packer_run_uuid": "5950db35-f75c-e09c-de7d-9e307b89bdc1",
      "custom_data": {
        "tenant_id": "{AZ_TENANT_ID_tenant01}",
        "subscription_id": "{AZ_SUBSCRIPTION_ID_tenant01}"
      }
    },
    {
      "name": "tenant02",
      "builder_type": "azure-arm",
      "build_time": 1724179775,
      "files": null,
      "artifact_id": "/subscriptions/{AZ_SUBSCRIPTION_ID}/resourceGroups/packer-build-images/providers/Microsoft.Compute/images/azure_ubuntu-2204_sigtenant22_0.0.26",
      "packer_run_uuid": "5950db35-f75c-e09c-de7d-9e307b89bdc1",
      "custom_data": {
        "tenant_id": "{AZ_TENANT_ID_tenant02}",
        "subscription_id": "{AZ_SUBSCRIPTION_ID_tenant02}"
      }
    }
  ],
  "last_run_uuid": "5950db35-f75c-e09c-de7d-9e307b89bdc1"
}

Potential References

An existing build property is exposed called "SourceImageName" -> https://developer.hashicorp.com/packer/integrations/hashicorp/azure/latest/components/builder/arm#build-shared-information-variables