Packer Machine Image Automation

Source Image → Packer Builds VM → Runs Provisioners → Creates Machine Image
(Ubuntu 22.04)   (temporary)     (install software)    (AMI, Azure Image)

# web-server.pkr.hcl
packer {
  required_plugins {
    amazon = {
      version = ">= 1.3.0"
      source  = "github.com/hashicorp/amazon"
    }
  }
}

source "amazon-ebs" "web" {
  ami_name      = "web-server-{{timestamp}}"
  instance_type = "t3.medium"
  region        = "eu-west-1"
  
  source_ami_filter {
    filters = {
      name                = "ubuntu/images/hvm-ssd/ubuntu-jammy-22.04-amd64-server-*"
      root-device-type    = "ebs"
      virtualization-type = "hvm"
    }
    most_recent = true
    owners      = ["099720109477"]  # Canonical
  }
  
  ssh_username = "ubuntu"
}

build {
  sources = ["source.amazon-ebs.web"]

  provisioner "shell" {
    inline = [
      "sudo apt-get update",
      "sudo apt-get install -y nginx nodejs npm",
      "sudo systemctl enable nginx",
    ]
  }

  provisioner "file" {
    source      = "nginx.conf"
    destination = "/tmp/nginx.conf"
  }

  provisioner "shell" {
    inline = [
      "sudo mv /tmp/nginx.conf /etc/nginx/nginx.conf",
      "sudo nginx -t",
    ]
  }
}

packer init .
packer build web-server.pkr.hcl
# ==> Builds finished: ami-0123456789abcdef0

source "amazon-ebs" "web" {
  ami_name = "web-server-{{timestamp}}"
  # ... AWS config
}

source "azure-arm" "web" {
  managed_image_name = "web-server-{{timestamp}}"
  # ... Azure config
}

source "docker" "web" {
  image  = "ubuntu:22.04"
  commit = true
}

build {
  sources = [
    "source.amazon-ebs.web",
    "source.azure-arm.web",
    "source.docker.web",
  ]

  provisioner "shell" {
    inline = [
      "apt-get update && apt-get install -y nginx",
    ]
  }
}

provisioner "ansible" {
  playbook_file = "ansible/web-server.yml"
  extra_arguments = [
    "--extra-vars", "env=production",
  ]
}

# ansible/web-server.yml
- hosts: all
  become: true
  roles:
    - common
    - nginx
    - node-exporter
    - security-hardening

# GitHub Actions
jobs:
  build-ami:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      
      - name: Setup Packer
        uses: hashicorp/setup-packer@main
      
      - name: Init
        run: packer init .
      
      - name: Validate
        run: packer validate .
      
      - name: Build
        run: packer build -var "version=${{ github.sha }}" .
        env:
          AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
          AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}

variable "app_version" {
  type    = string
  default = "latest"
}

data "amazon-ami" "base" {
  filters = {
    name = "ubuntu/images/hvm-ssd/ubuntu-jammy-22.04-*"
  }
  most_recent = true
  owners      = ["099720109477"]
}

source "amazon-ebs" "web" {
  source_ami = data.amazon-ami.base.id
  # ...
}