Psenv

Work in progress

Shim to load environment variables from AWS Systems Manager Parameter Store into ENV.

Psenv currently heavily borrows from Dotenv, mainly because I use it in roughly every project so it made sense for the APIs to match.

Installation

Rails

Add this line to your application's Gemfile:

gem 'psenv-rails'

And then execute:

$ bundle

Set the PARAMETER_STORE_PATH environment variable with the AWS Parameter Store path that you wish to load.

Spring preloader

The Spring preloader does not detect environment variable changes as application changes. This means that when using Spring, new or changed environment variables from AWS SSM Parameter Store will not become available immediately. This also applies to any change to PARAMETER_STORE_PATH.

There are two work-arounds. You can force Spring to restart by killing it with bundle exec spring stop.

Alternatively, you can update your Spring configuration to reload variables using Psenv after the process forks. To do this, add the following configuration to config/spring.rb:

Spring.after_fork do
  Psenv.load
end

Plain Ruby

Add this line to your application's Gemfile:

gem 'psenv'

And then execute:

$ bundle

Set the PARAMETER_STORE_PATH environment variable with the AWS Parameter Store path that you wish to load.

Finally, trigger the loading:

require 'psenv'
Psenv.load

Usage

• Create a variable in parameter store using the AWS console or the CLI

aws ssm put-parameter \
	--name /psenv/test/API_KEY \
	--value "api_key_value" \
	--type String

• Ensure your application has at least the following IAM permissions
  • ssm:GetParametersByPath on resource arn:aws:ssm:::parameter/psenv/test/*
• Set the PARAMETER_STORE_PATH environment variable to /psenv/test/

This example will set the API_KEY to api_key_value and make it available to your application.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/atomaka/psenv.

License

The gem is available as open source under the terms of the MIT License.