Capistrano Autoscale

This is a fork of lserman/capistrano-elbas, with several improvements.

Capistrano-autoscale was written to ease the deployment of Rails applications to AWS Auto Scaling Groups. During your Capistrano deployment, capistrano-autoscale will:

• Suspend Launch & Terminate processes on the Auto Scaling Group.
• Deploy your code to each running instance connected to a given Auto Scaling Group.
• After deployment, create an AMI from one of the running instances.
• Create a new Launch Template version with the AMI ID based on the current Auto Scaling Group's Launch Template.
• Delete any outdated Launch Template versions, AMIs and snapshots created by previous deployments.
• Resume Launch & Terminate processes on the Auto Scaling Group.

Installation

Add to Gemfile, then run bundle:

gem 'capistrano-autoscale', require: false, git: 'https://github.com/KentaaNL/capistrano-autoscale.git'

Add to Capfile:

require 'capistrano/autoscale'

Configuration

Setup AWS credentials:

set :aws_access_key_id,     ENV['AWS_ACCESS_KEY_ID']
set :aws_secret_access_key, ENV['AWS_SECRET_ACCESS_KEY']
set :aws_region,            ENV['AWS_REGION']

To configure the prefix that AMIs will get (defaults to stage name):

set :aws_autoscale_ami_prefix, "my-ami"

To add custom tags to AMIs and snapshots you can specify a hash:

set :aws_autoscale_ami_tags, { "Environment" => "Sandbox" }
set :aws_autoscale_snapshot_tags, { "Environment" => "Sandbox" }

By default, the Launch & Terminate processes will be suspended during deployment. To disable this:

set :aws_autoscale_suspend_processes, false

After deployment, any outdated Launch Template versions, AMIs and snapshots will be deleted. By default, the number of keep_releases will be kept. To change this, set:

set :aws_autoscale_cleanup_old_versions, true
set :aws_autoscale_keep_versions, 8

Usage

Instead of using Capistrano's server method, use autoscale instead in deploy/<environment>.rb (replace <environment> with your environment). Provide the name of your Auto Scaling group instead of a hostname:

autoscale 'my-autoscale-group', user: 'apps', roles: [:app, :web, :db]

If you have multiple autoscaling groups to deploy to, specify each of them:

autoscale 'app-autoscale-group', user: 'apps', roles: [:app, :web]
autoscale 'worker-autoscale-group', user: 'apps', roles: [:worker]

Run cap production deploy.

Note: Your Auto Scaling Group must use Launch Templates as opposed to Launch Configurations. This allows capistrano-autoscale to simply create a new Launch Template version with the new AMI ID after a deployment. Failure to use a Launch Template will result in a Capistrano::Autoscale::Errors::NoLaunchTemplate error.