This tool is no longer maintained.
CloudFormation and related services provide a way to manage infrastructure state in "the cloud." This
gem and its included command (
aws-cft) build on top of this state management system to create an
infrastructure management solution native to the AWS environment.
aws-cft-tools empowers users to organize their CloudFormation templates using any form of directory
structure, without the need to tediously deploy their templates in a specific order or create quickly
outdated scripts to manage the deployment thereof. This project links together templates using the
Export/ImportValue features of CloudFormation to determine the order of operations, manages stack
names, and supports multiple parallel "Environments" within a single AWS account.
Add this line to your application's Gemfile:
And then execute:
Or install it yourself as:
$ gem install aws-cft-tools
aws-cft command provides access to a number of run books that manage different tasks.
aws-cft deployto deploy CloudFormation templates
aws-cft diffto see differences between local and deployed CloudFormation templates
aws-cft hoststo list running EC2 instances
aws-cft imagesto list available AMIs
aws-cft initto initialize a new infrastructure project
aws-cft retractto remove deployed CloudFormation templates
aws-cft stacksto list CloudFormation stacks
USAGE.adoc for more details.
CloudFormation templates are managed in any number of directories that correspond to infrastructure
layers. For example,
applications. The layers are completely
Templates also belong to a "role" based on their participation in the infrastructure. The role is defined with metadata in the template:
Templates are deployed or retracted based on their dependency order. The scripts try to discover this
by examining the values exported by one template and imported by another. When this fails to describe
the proper dependencies of a template, you can add an explicit dependency in the template's
This follows the pattern for listing explicit dependencies between resources in a template.
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
aws-cft-tools is designed to work in an "infrastructure as code" DevOps environment. Infrastructure is
software that is developed, tested, peer reviewed, and finally merged and deployed.
When first using CloudFormation, it is very easy to launch a single stack and get off the ground quickly. As you move forward, users quickly find out that their Templates need to be managed in source control. Later, users want to test their infrastructure changes in a different Environment, so a "dev" layer is created, then an "integration", then a "staging", etc. Before too long, launching stacks is a nightmare due to dependency conflicts, manual naming failures of Stacks, typos, and so on. On top of that, remembering which Stacks have been deployed for which environment becomes impossible, so infrastructure drift is inevitable.
This tool builds on top of the normal progression of teams using CloudFormation, enabling managed Environments using parameters on templates. It offers simple deployments to roll out a full stack in a new environment with a single command. It allows developers to continue to use CloudFormation for all their infrastructure, while vastly simplifying the deployment and retraction process.
Ansible provides features that are a mix of infrastructure management and
instance configuration. For example, Ansible can do the work of TerraForm and Chef, combined. However,
Ansible works best when working with an expected inventory of resources. It makes changes to bring
infrastructure in line with the inventory.
aws-cft-tools only manages CloudFormation templates and leaves
configuration of instances to other tools such as Chef or Ansible.
Using Ansible with
Ansible can manage the production of an Amazon Machine Image (AMI). It can spin up a temporary EC2 instance
and install all of the necessary system packages, make any configuration changes, and trigger the creation
of a tagged AMI. If the AMI is tagged with an Environment and Role, then
aws-cft-tools can discover the
AMI and provide it as a parameter to any CloudFormation stacks that require the image. For example, creating
a new AMI and then using
aws-cft-tools to deploy the CloudFormation Template for an auto-scaling group
that uses that AMI can result in the deployment of a new version of an application.
aws-cft-tools are solving similar problems with fundamentally
different approaches. TerraForm is designed to work with multiple cloud providers while
specific to AWS. So TerraForm can't depend on features that aren't provided by all cloud providers. Thus,
TerraForm requires a state file that introduces some complexity into managing infrastructure.
aws-cft-tools doesn't mean infrastructure management is less complex than when using TerraForm. Only
that the complexity is different. Instead of managing a state file outside of AWS,
that AWS is the source of all state information.
Rather than computing changes, for example,
aws-cft-tools requests a list of changes from AWS for a given
change in template and parameters. This does take more time than if all of that information was in a local
state file, but it ensures that any changes reflect the current deployment.
In exchange for taking a little more time to make changes (e.g., pull requests and code reviews after initial development), teams can work on different parts of the infrastructure without having to coordinate with each other.
Building Gem for Local Use
bundle install --deployment --without development test
gem build ./aws-cft-tools.gemspec
Minimum IAM Policy to run initial script
"Resource": [ "*" ]
Please do not submit an issue on GitHub for a security vulnerability. Please contact the development team through the Certify Help Desk at email@example.com.
Be sure to include all the pertinent information.
Aws-cft-tools is licensed permissively under the Apache License v2.0. A copy of that license is distributed with this software.
We welcome contributions. Please read
CONTRIBUTING.md for how to contribute.
We strive for a welcoming and inclusive environment for the aws-cft-tools project.
Please follow this guidelines in all interactions:
- Be Respectful: use welcoming and inclusive language.
- Assume best intentions: seek to understand others' opinions.