GoCD server plugin for bringing up Amazon EC2 instances as its agents on demand.
Compatible with version 5.0 of the elastic agent endpoint (GoCD server versions starting from 19.3.0).
Copy the file build/libs/gocd-ec2-elastic-agent-plugin-VERSION.jar to the GoCD server under ${GO_SERVER_DIR}/plugins/external
and restart the server.
Prepare AMI, security groups and subnets for the agents.
Tested on GoCD server versions 19.11.0 and 19.12.0.
This is the most important step, where you will prepare a base image for the agents. Create new clean EC2 instance and install there all the tools and configurations that your agents may need. After that, follow up the official guide to install Go-Agent. Do not connect it to the server yet, nor enable auto startup of go-agent.service! All this will be done by the plugin itself with the help of the user data scripts. Before stopping this instance perform cleanup with the following commands:
rm -rf /var/lib/cloud/*
rm -rf /var/log/cloud-init*
rm -rf /usr/share/go-agent/go-agent.pid
rm -rf /usr/share/go-agent/config/*
rm -rf /var/log/go-agent/*
rm -rf /var/lib/go-agent/config/*Finally, create new Amazon Machine Image from your instance. Each Elastic Agent Profile can use different AMI to suit your needs.
You will need to setup some connectivity between your GoCD server and elastic agents. You may also want to allow any other inbound/outbound traffic to the agents, like tunnels, version control systems or repositories. The most straightforward way to achieve this is with security groups.
Once you have all your security groups defined, put their identifiers into the Elastic Agent Profile and they will be automatically assigned to every newly created EC2 instance.
To be able to launch new agents you need to have at least one subnet in your VPC where you will put your newly created instances. You can define several subnets (ideally in different availability zones) in the elastic agent profile and the plugin will choose randomly one of them each time it has to create new instance. If the chosen availability zone has run out of your requested instance type, the plugin will try to bring up instance in the next subnet.
Also, remember to enable auto-assign public IP address to the subnets.
To build the jar, run ./gradlew clean assemble
This project is fully based on GoCD Elastic agent plugin skeleton and GoCD Elastic agent plugin for Docker. The structure and some parts of code are taken directly from these projects.
The GoCD Elastic agent plugin for AWS EC2 is supplied "AS IS", use is at your own risk. Author and contributors expressly disclaim all warranties nor support of any kind.