Packer Bamboo Elastic Agent

Creates an AMI to use as a customised Bamboo Elastic Agent

Getting started

To create an AMI to use as a customised Bamboo Elastic Agent, run the following at the command line

$ packer build \
    -var 'aws_access_key=foo' \
    -var 'aws_secret_key=bar' \
    bamboo-elastic-agent.json

NOTE: Packer will attempt to lookup AWS credentials from the environment variables and local AWS configuration files if not specified in the template. Refer to https://www.packer.io/docs/builders/amazon.html#specifying-amazon-credentials

Prerequisites

You will need to have Packer installed to create AMIs. Packer is distributed as a binary package which can be downloaded from https://www.packer.io/downloads.html

Alternative method on MacOS

On a Mac, Homebrew can be used to install Packer

brew install packer

AWS Credentials

You will need an IAM user account to run this locally on your computer. The script can also be run on an EC2 instance with an instance profile granting sufficient permissions. Refer to https://www.packer.io/docs/builders/amazon.html

The following policy document provides the minimal set permissions necessary for Packer to work:

{
  "Version": "2012-10-17",
  "Statement": [{
      "Effect": "Allow",
      "Action" : [
        "ec2:AttachVolume",
        "ec2:CreateVolume",
        "ec2:DeleteVolume",
        "ec2:CreateKeypair",
        "ec2:DeleteKeypair",
        "ec2:DescribeSubnets",
        "ec2:CreateSecurityGroup",
        "ec2:DeleteSecurityGroup",
        "ec2:DescribeSecurityGroups",
        "ec2:AuthorizeSecurityGroupIngress",
        "ec2:CreateImage",
        "ec2:CopyImage",
        "ec2:RunInstances",
        "ec2:TerminateInstances",
        "ec2:StopInstances",
        "ec2:DescribeVolumes",
        "ec2:DetachVolume",
        "ec2:DescribeInstances",
        "ec2:CreateSnapshot",
        "ec2:DeleteSnapshot",
        "ec2:DescribeSnapshots",
        "ec2:DescribeImages",
        "ec2:RegisterImage",
        "ec2:DeregisterImage",
        "ec2:CreateTags",
        "ec2:ModifyImageAttribute",
        "ec2:GetPasswordData",
        "ec2:DescribeTags",
        "ec2:DescribeImageAttribute",
        "ec2:CopyImage",
        "ec2:DescribeRegions",
        "ec2:ModifyInstanceAttribute"
      ],
      "Resource" : "*"
  }]
}

Modifying the script

You can modify the bash script in the scripts directory to install what your build and deployments require. You can also manage a fleet of AMIs by creating a separate script for each type of agent required. You will need to also copy the packer JSON file to a new file.

Modifying the source AMI

The source AMI used by Packer is the Atlassian stock image for elastic Bamboo agents. This AMI already has all the required packages installed to connect to Bamboo. Each region has their own AMI so be sure to check the region before updating the source AMI.

Further reading

Further details can be found here https://developer.atlassian.com/blog/2015/07/bamboo-packer/