azure-image-builder

name: azure-image-builder description: Build Azure managed images and Azure Compute Gallery images with Packer. Use when creating custom images for Azure VMs.

Azure Image Builder

Build Azure managed images and Azure Compute Gallery images using Packer's azure-arm builder.

Reference: Azure ARM Builder

Note: Building Azure images incurs costs (compute, storage, data transfer). Builds typically take 15-45 minutes depending on provisioning and OS.

Basic Managed Image

packer {
  required_plugins {
    azure = {
      source  = "github.com/hashicorp/azure"
      version = "~> 2.0"
    }
  }
}

variable "client_id" {
  type      = string
  sensitive = true
}

variable "client_secret" {
  type      = string
  sensitive = true
}

variable "subscription_id" {
  type = string
}

variable "tenant_id" {
  type = string
}

variable "resource_group" {
  type    = string
  default = "packer-images-rg"
}

locals {
  timestamp = regex_replace(timestamp(), "[- TZ:]", "")
}

source "azure-arm" "ubuntu" {
  client_id       = var.client_id
  client_secret   = var.client_secret
  subscription_id = var.subscription_id
  tenant_id       = var.tenant_id

  managed_image_resource_group_name = var.resource_group
  managed_image_name                = "my-app-${local.timestamp}"

  os_type         = "Linux"
  image_publisher = "Canonical"
  image_offer     = "0001-com-ubuntu-server-jammy"
  image_sku       = "22_04-lts-gen2"

  location = "East US"
  vm_size  = "Standard_B2s"

  azure_tags = {
    Name      = "my-app"
    BuildDate = local.timestamp
  }
}

build {
  sources = ["source.azure-arm.ubuntu"]

  provisioner "shell" {
    inline = [
      "sudo apt-get update",
      "sudo apt-get upgrade -y",
    ]
  }
}

Azure Compute Gallery

source "azure-arm" "ubuntu" {
  client_id       = var.client_id
  client_secret   = var.client_secret
  subscription_id = var.subscription_id
  tenant_id       = var.tenant_id

  os_type         = "Linux"
  image_publisher = "Canonical"
  image_offer     = "0001-com-ubuntu-server-jammy"
  image_sku       = "22_04-lts-gen2"

  location = "East US"
  vm_size  = "Standard_B2s"

  shared_image_gallery_destination {
    resource_group       = "gallery-rg"
    gallery_name         = "myImageGallery"
    image_name           = "ubuntu-webapp"
    image_version        = "1.0.${formatdate("YYYYMMDD", timestamp())}"
    replication_regions  = ["East US", "West US 2"]
    storage_account_type = "Standard_LRS"
  }
}

Authentication

Service Principal

# Create service principal
az ad sp create-for-rbac \
  --name "packer-sp" \
  --role Contributor \
  --scopes /subscriptions/<subscription-id>

# Set environment variables
export ARM_CLIENT_ID="<client-id>"
export ARM_CLIENT_SECRET="<client-secret>"
export ARM_SUBSCRIPTION_ID="<subscription-id>"
export ARM_TENANT_ID="<tenant-id>"

Managed Identity

source "azure-arm" "ubuntu" {
  use_azure_cli_auth = true
  subscription_id    = var.subscription_id
  # ... rest of configuration
}

Build Commands

# Set authentication
export ARM_CLIENT_ID="your-client-id"
export ARM_CLIENT_SECRET="your-client-secret"
export ARM_SUBSCRIPTION_ID="your-subscription-id"
export ARM_TENANT_ID="your-tenant-id"

# Initialize plugins
packer init .

# Validate template
packer validate .

# Build image
packer build .

Common Issues

Authentication Failed

• Verify service principal credentials
• Ensure Contributor role on resource group
• Check subscription and tenant IDs

Compute Gallery Version Exists

• Image versions are immutable
• Use unique version numbers with date/build number
• Cannot overwrite existing versions

Timeout During Provisioning

• Check network connectivity from build VM
• Verify NSG rules allow required traffic
• Increase timeout if needed

References

• Azure ARM Builder
• Azure Compute Gallery