Convection

A fully generic, modular DSL for AWS CloudFormation

This gem aims to provide a reusable model for AWS CloudFormation in Ruby. It exposes a DSL for template definition, and a simple, decoupled abstraction of a CloudFormation Stack to compile and apply templates.

Contributing

Please read our Contributing guidelines for more information on contributing to Convection.

Installation

Add this line to your application's Gemfile:

gem 'convection'

And then execute:

$ bundle

Or install it yourself as:

$ gem install convection

##CLI Commands

Converging

• To converge all stacks in your cloudfile run convection converge in the same directory as your cloudfile or use --cloudfiles and specify the path to the cloudfile. If you provide the name of your stack as a additional argument such as convection converge my-stack-name then all stacks above and including the stack you specified will be converged.
• To converge a stack group run convection converge --stack_group YOUR_STACK_GROUP_NAME
• To converge a specific stack or a list of stacks run convection converge --stacks stackA stackB ...
• To converge multiple cloudfiles at the same time run use the --cloudfiles option providing the path to the cloudfiles. Example bundle exec convection converge --cloudfiles us-east-1/Cloudfile eu-central-1/Cloudfile

Diff

• To display a diff between your local changes and the version of your stack in cloud formation of your changes run convection diff.
• To diff the changes in a stack group run convection diff --stack_group YOUR_STACK_GROUP_NAME
• To diff the changes for a specific stack or a list of stacks run convection diff --stacks stackA stackB ...

Help

• To print out a list of available cli options with their descriptions run convection help.

Print

• To print out the cloud formation template for a specific stack run convection print-template my-stack-name.

Validate

• To validate your stack is not missing a required resource run convection validate my-stack-name.

Documentation

We highly recommend consulting the getting started guide for a in depth walk through on how to to set up your project and create and deploy a stack. Example stacks and resources are available in the convection/example folder

Additionally you can generate the Ruby API documentation by executing bundle exec rake yard.

TODO: Script to automatically create new AWS resources

Amazon publishes a spec for Cloudformation: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/cfn-resource-specification.html

We should create a tool that uses that to create convection resource code.

License

Convection is distributed under the MIT license - please refer to the LICENSE for more information.