Packer

Skill 2 of 20

Azure Image Builder

Build Azure managed images and Azure Compute Gallery images with Packer.

1 minute · 109 words · 8 sections

Install

$ npx skills add hashicorp/agent-skills --skill azure-image-builder

$ npx skills add hashicorp/agent-skills

» /plugin marketplace add hashicorp/agent-skills

The first command installs just this skill, by the name in its SKILL.md; the second installs the whole repository.

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

Reference: Azure ARM Builder (opens in a new tab)

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

About this skill

Trigger

Build Azure managed images and Azure Compute Gallery images with Packer. Use when creating custom images for Azure VMs.

The verbatim description from this skill’s front matter — the string an agent matches on to decide whether to load it.

Colophon for this issue

Colophon

How this issue was made

Source

github.com/hashicorp/agent-skills, branch main, last pushed 21 September 2026.

Licence

MPL-2.0 — the text of every skill is reproduced unmodified, frontmatter included, under the upstream licence.

Discovery

20 skills found by walking the repository tree for SKILL.md, not by matching a directory convention. 2 distinct layouts observed: plugins/packer/skills/*/SKILL.md, plugins/terraform/skills/*/SKILL.md.

Issue colours

Resolved from the awesome-design-md registry — hue 304°, chroma 0.190. Two accent tones are generated per issue and each is proven against its own ground before it ships: a single accent that passes AA on both light and dark paper is arithmetically impossible.

Typefaces

Display: hashicorpSans is not a face we ship; the reader's own choice is used.
Body: hashicorpSans is not a face we ship; the reader's own choice is used.

We never load a typeface at request time from a third-party origin, so a brand face we do not already self-host is substituted rather than fetched.

Heading repairs

1 repair applied to this skill so the document has one h1 and no skipped levels:

Removed “Azure Image Builder”, a leading h1 that duplicated the skill title.

Spec compliance

Every skill satisfies the Agent Skills specification’s frontmatter rules.

Images

Images inside a skill come from the upstream repository. Where the author gave no alternative text we mark the image decorative rather than inventing a description — a plausible caption we made up is worse than none for the reader who depends on it.

Marketplace

A plugin manifest is published at .claude-plugin/marketplace.json by HashiCorp, declaring 2 plugins. It is read for editorial metadata only — never as the skill index, which is always the repository tree.

Signal

Install counts come from skills.sh. They measure downloads, not quality, and an unranked repository is not an unread one.

Agent surfaces

The whole issue is available as one markdown document at /hashicorp/agent-skills.md, and each skill at its own .md URL.

Publication

Set by Skills Docs from the source repository. Body text is Literata at the reader’s chosen size and measure; code is Geist Mono. Nothing on this page was written by us except this paragraph.

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

Reference: Azure ARM Builder (opens in a new tab)

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

Azure Image Builder

Basic Managed Image

Azure Compute Gallery

Authentication

Service Principal

Managed Identity

Build Commands

Common Issues

References

About this skill

Trigger

Colophon

Azure Image Builder

Basic Managed Image

Azure Compute Gallery

Authentication

Service Principal

Managed Identity

Build Commands

Common Issues

References

About this skill

Trigger

Colophon