Create Amazon Machine Image (AMI) using Packer with Wordpress pre-installed

Packer is an open source tool for creating identical machine images for multiple platforms from a single source configuration.

Prerequisites

Packer is installed and you know what it does
You have an active AWS account (Free tier account is fine)
git is installed
Understand JSON file structure
Basics of bash command

Getting Started

To install Packer run

wget https://releases.hashicorp.com/packer/1.5.1/packer_1.5.1_linux_amd64.zip
unzip packer_1.5.1_linux_amd64.zip
sudo mv packer /bin

Verify if Packer is installed

packer version

File Structure

Read below section to understand the purpose of each file in this repo:

FileName	Purpose
wordpress.json	A json file which is used by packer to build CentOS based AMI
files	Folder to keep provisioning bash script and dependencies for CentOS
files/r1softagent.repo	Contains repository information
files/userdata.sh	Bash script to povision softwares in image

Quick Start

After Packer is installed, create your first template, which tells Packer what platforms to build images for and how you want to build them. In our case, we'll create a simple AMI that has Wordpress pre-installed. Save this file as wordpress.json.

{
    "builders": [
      {
        "type": "amazon-ebs",
        "source_ami_filter": {
            "filters": {
                "virtualization-type": "hvm",
                "name": "CentOS Linux 7 x86_64 HVM EBS ENA 1901_01-b7ee8a69-ee97-4a49-9e68-afaee216db2e-*",
                "root-device-type": "ebs"
                },
            "owners": ["679593333241"],
            "most_recent": true
            },
        "instance_type": "t2.micro",
        "ssh_username": "centos",
        "region": "us-east-1",
        "ami_name": "wordpress-example {{timestamp}}"
      }
    ],

Provisioners are responsible for installing and configuring software on the running machines prior to turning them into machine images. Packer provides in-built support for different kinds of provisioners mainly Shell, File, Poweshell, Ansible, Chef and Puppet etc.

"provisioners": [
      {
     "type": "shell",
        "script": "../files/userdata.sh"        
        },
    {
      "type": "breakpoint",
      "note": "Wait for you to delete"
        }
     ]
}

Create AMI

Run below command to create AMI

$ packer validate wordpress.json

You should see validation output

Template validated successfully.