packer-ami-aws

Build an Ubuntu Amazon Machine Image (AMI) with:

• nginx enabled at boot
• static web content copied from a configurable Git repository
• Docker Engine installed from Docker's official Ubuntu apt repository

The template is written in Packer HCL2 (packer.hcl) and uses separate variable definitions plus a reusable provisioning script for maintainability.

Packer automatically selects the most recent official Canonical Ubuntu 22.04 LTS (Jammy) amd64 AMI in the configured AWS region. The lookup is limited to Canonical's AWS owner account and EBS-backed HVM Ubuntu server images, so you do not need to find or maintain a source_ami ID.

Prerequisites

• Packer 1.8 or newer
• AWS credentials available to Packer, for example through AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_DEFAULT_REGION, or through your standard AWS profile/role configuration
• A VPC, public subnet, and security group for the temporary build instance

Ensure the build subnet and security group allow Packer to connect over SSH:

• the subnet auto-assigns or allows an associated public IPv4 address
• the route table has a route to an internet gateway
• the security group allows inbound SSH from the machine running Packer
• outbound internet access is available for apt, GitHub, and Docker package downloads

Configure variables

Create a local variable file from the example and fill in your AWS resource IDs:

cp packer-vars.example.hcl packer-vars.pkrvars.hcl

region            = "us-east-1"
vpc_id            = "vpc-0123456789abcdef0"
subnet_id         = "subnet-0123456789abcdef0"
security_group_id = "sg-0123456789abcdef0"

packer-vars.pkrvars.hcl is ignored by Git so local infrastructure values are not committed accidentally.

Ubuntu source selection

The default source is Canonical's latest Jammy 22.04 amd64 server AMI. To select another supported Canonical Ubuntu release or architecture, add these optional settings to your variable file:

# ubuntu_release      = "jammy-22.04"
# ubuntu_architecture = "amd64"

ubuntu_release follows Canonical's AMI naming format (for example, noble-24.04), and ubuntu_architecture must be amd64 or arm64. If you choose arm64, use an ARM-compatible build instance type such as t4g.micro.

Build the AMI

Initialize plugins:

packer init .

Format and validate the template:

packer fmt .
packer validate -var-file=packer-vars.pkrvars.hcl .

Build the AMI:

packer build -var-file=packer-vars.pkrvars.hcl .

Customizing the web content

By default, the AMI copies index.html, style.css, and scorekeeper.js from the explicit main ref of https://github.com/guycalledavinash/webhook-testing.git into /var/www/html.

Override the content repository and ref at build time:

packer build \
  -var-file=packer-vars.pkrvars.hcl \
  -var='web_content_repo=https://github.com/example/my-static-site.git' \
  -var='web_content_ref=v1.2.3' \
  .

web_content_ref can be a branch, tag, or other Git ref. Use an immutable tag or commit SHA for production builds: pinning the exact content revision ensures later commits to the repository do not change the files baked into an AMI rebuilt from the same Packer configuration.

The repository must contain index.html, style.css, and scorekeeper.js at its root.

Security notes

This project no longer replaces Docker's systemd unit or exposes the unauthenticated Docker TCP socket on 0.0.0.0:2375. Exposing that socket allows remote root-equivalent access to the instance. Use SSH, TLS-protected Docker contexts, or a private remote-management approach instead.