Serfdom

The easiest way to create identifiable environments for Elastic Beanstalk applications.

Run serfdom and create the master-2-2-1-6a8ea5e environment.

Serfdome will ask for the NODE_ENV variable to use (development, staging or production by default), and create a new EB environment for your application with a unique name of <branch name>-<application version>-<git commit sha> for you to easily be able to identify your environments.

Why

This is the perfect module to use if you want zero downtime deployments using CNAME swaps in AWS Elastic Beanstalk.

Our suggestion is to tie a DNS record to a specific application CNAME. For example, manually create your first EB environment named my-app-prod.elasticbeanstalk.com. Then, through your DNS records, map my-app.com to CNAME my-app-prod.elasticbeanstalk.com.

From that point forward, use this serfdom app to launch new environments. They will be specifically identifiable to what code is contained in the environment. Then, when you are happy with an environment, do a Swap CNAMEs through Elastic Beanstalk to switch your prod CNAME with your newest environment. You then have a non-destructive rollout plan for production releases.

Prerequisites

• Your application must already be an AWS Elastic Beanstalk application.

You can do this by installing the AWS CLI and running eb init in your applications root directory

• Your user credentials must already be stored in your AWS credentials file

How to Install

npm i -g serfdom

How to Use

1. cd my-eb-app
2. serfdom
3. ...
4. profit!

Configuration

Serfdom can run in any Elastic Beanstalk application out of the box. But you can also specify a .serfdom JSON configuration file with the following parameters.

Environment Type List

You may specify an array of strings to use as your environment names. This will specify both the NODE_ENV environment variable, and it will be included in the environment name/url.

Example .serfdom configuration override:

"environments": [
  "red",
  "blue"
]

Environment Tags

An array of strings to add as tags to your AWS environment. serfdom will always add the tag environment=${CHOSEN_ENV_TYPE}

AWS imposes the following restrictions on tags:

• Keys and values can contain any alphabetic character in any language, any numeric character, white space, invisible separator, and the following symbols: _ . : / + - @
• Keys can contain up to 128 characters. Values can contain up to 256 characters.
• Keys and values are case sensitive.
• Values cannot match the environment name.
• Values cannot include either aws: or elasticbeanstalk:.

Example .serfdom configuration addition:

{
  "tags": [
    "project=example",
    "team=extreme"
  ]
}