RubyTerraform

A simple wrapper around the Terraform binary to allow execution from within a Ruby program or Rakefile.

Installation

Add this line to your application's Gemfile:

gem 'ruby-terraform'

And then execute:

$ bundle

Or install it yourself as:

$ gem install ruby-terraform

Usage

RubyTerraform needs to know where the terraform binary is located before it can do anything. By default, RubyTerraform looks on the path however this can be configured with:

RubyTerraform.configure do |config|
  config.binary = 'vendor/terraform/bin/terraform'
end

In addition, each command that requires the terraform binary (all except clean) takes a binary keyword argument at initialisation that overrides the global configuration value.

Currently, there is partial support for the following commands:

• RubyTerraform::Commands::Clean: clean up all locally held terraform state and modules.
• RubyTerraform::Commands::Init: executes terraform init
• RubyTerraform::Commands::Get: executes terraform get
• RubyTerraform::Commands::Apply: executes terraform apply
• RubyTerraform::Commands::Destroy: executes terraform destroy
• RubyTerraform::Commands::Output: executes terraform output
• RubyTerraform::Commands::RemoteConfig: executes terraform remote config

RubyTerraform::Commands::Clean

The clean command can be called in the following ways:

RubyTerraform.clean
RubyTerraform.clean(directory: 'infra/.terraform')
RubyTerraform::Commands::Clean.new(directory: 'infra/.terraform').execute
RubyTerraform::Commands::Clean.new.execute(directory: 'infra/.terraform')

When called, it removes the contents of the .terraform directory in the working directory by default. If another directory is specified, it instead removes the specified directory.

RubyTerraform::Commands::Init

The init command will initialise a terraform environment. It can be called in the following ways:

RubyTerraform.init
RubyTerraform.init(source: 'some/module/path', path: 'infra/module')
RubyTerraform::Commands::Init.new.execute
RubyTerraform::Commands::Init.new.execute(
    source: 'some/module/path', 
    path: 'infra/module')

The init command supports the following options passed as keyword arguments:

• source: the source module to use to initialise; required if path is specified
• path: the path to initialise.
• backend: true/false, whether or not to configure the backend.
• get: true/false, whether or not to get dependency modules.
• backend_config: a map of backend specific configuration parameters.
• no_color: whether or not the output from the command should be in color; defaults to false.
• plugin_dir: directory containing plugin binaries. Overrides all default; search paths for plugins and prevents the automatic installation of plugins.

RubyTerraform::Commands::Get

The get command will fetch any modules referenced in the provided terraform configuration directory. It can be called in the following ways:

RubyTerraform.get(directory: 'infra/networking')
RubyTerraform::Commands::Get.new.execute(directory: 'infra/networking')

The get command supports the following options passed as keyword arguments:

• directory: the directory containing terraform configuration; required.
• update: whether or not already downloaded modules should be updated; defaults to false.
• no_color: whether or not the output from the command should be in color; defaults to false.

RubyTerraform::Commands::Plan

The plan command will generate the execution plan in the provided configuration directory. It can be called in the following ways:

RubyTerraform.plan(
  directory: 'infra/networking', 
  vars: {
    region: 'eu-central'
  })
RubyTerraform::Commands::Plan.new.execute(
  directory: 'infra/networking',
  vars: {
    region: 'eu-central'
  })

The plan command supports the following options passed as keyword arguments:

• directory: the directory containing terraform configuration; required.
• vars: a map of vars to be passed in to the terraform configuration.
• var_file: the path to a terraform var file; if both var_file and var_files are provided, all var files will be passed to terraform.
• var_files: an array of paths to terraform var files; if both var_file and var_files are provided, all var files will be passed to terraform.
• state: the path to the state file in which to store state; defaults to terraform.tfstate in the working directory or the remote state if configured.
• plan: the name of the file in which to save the generated plan.
• input: when false, will not ask for input for variables not directly set; defaults to true.
• destroy: when true, a plan will be generated to destroy all resources managed by the given configuration and state; defaults to false.
• no_color: whether or not the output from the command should be in color; defaults to false.

RubyTerraform::Commands::Apply

The apply command applies terraform configuration in the provided terraform configuration directory. It can be called in the following ways:

RubyTerraform.apply(
  directory: 'infra/networking', 
  vars: {
    region: 'eu-central'
  })
RubyTerraform::Commands::Apply.new.execute(
  directory: 'infra/networking',
  vars: {
    region: 'eu-central'
  })

The apply command supports the following options passed as keyword arguments:

• directory: the directory containing terraform configuration; required.
• vars: a map of vars to be passed in to the terraform configuration.
• var_file: the path to a terraform var file; if both var_file and var_files are provided, all var files will be passed to terraform.
• var_files: an array of paths to terraform var files; if both var_file and var_files are provided, all var files will be passed to terraform.
• state: the path to the state file in which to store state; defaults to terraform.tfstate in the working directory or the remote state if configured.
• backup: the path to the backup file in which to store the state backup.
• input: when false, will not ask for input for variables not directly set; defaults to true.
• no_backup: when true, no backup file will be written; defaults to false.
• no_color: whether or not the output from the command should be in color; defaults to false.
• auto_approve: if true, the command applys without prompting the user to confirm the changes; defaults to false.

RubyTerraform::Commands::Destroy

The destroy command destroys all resources defined in the terraform configuration in the provided terraform configuration directory. It can be called in the following ways:

RubyTerraform.destroy(
  directory: 'infra/networking', 
  vars: {
    region: 'eu-central'
  })
RubyTerraform::Commands::Destroy.new.execute(
  directory: 'infra/networking',
  vars: {
    region: 'eu-central'
  })

The destroy command supports the following options passed as keyword arguments:

• directory: the directory containing terraform configuration; required.
• vars: a map of vars to be passed in to the terraform configuration.
• var_file: the path to a terraform var file; if both var_file and var_files are provided, all var files will be passed to terraform.
• var_files: an array of paths to terraform var files; if both var_file and var_files are provided, all var files will be passed to terraform.
• state: the path to the state file containing the current state; defaults to terraform.tfstate in the working directory or the remote state if configured.
• force: if true, the command destroys without prompting the user to confirm the destruction; defaults to false.
• backup: the path to the backup file in which to store the state backup.
• no_backup: when true, no backup file will be written; defaults to false.
• no_color: whether or not the output from the command should be in color; defaults to false.

RubyTerraform::Commands::Output

The output command retrieves an output from a state file. It can be called in the following ways:

RubyTerraform.output(name: 'vpc_id')
RubyTerraform::Commands::Destroy.new.execute(name: 'vpc_id')

The output command supports the following options passed as keyword arguments:

• name: the name of the output to retrieve; required.
• state: the path to the state file containing the current state; defaults to terraform.tfstate in the working directory or the remote state if configured.
• no_color: whether or not the output from the command should be in color; defaults to false.

RubyTerraform::Commands::RemoteConfig

The remote config command configures storage of state using a remote backend. It can be called in the following ways:

RubyTerraform.remote_config(
  backend: 's3',
  backend_config: {
    bucket: 'example-state-bucket',
    key: 'infra/terraform.tfstate',
    region: 'eu-west-2'
  })
RubyTerraform::Commands::RemoteConfig.new.execute(
  backend: 's3',
  backend_config: {
    bucket: 'example-state-bucket',
    key: 'infra/terraform.tfstate',
    region: 'eu-west-2'
  })

The remote config command supports the following options passed as keyword arguments:

• backend: the type of backend to use; required.
• backend_config: a map of backend specific configuration parameters; required.
• no_color: whether or not the output from the command should be in color; defaults to false.

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/tobyclemson/ruby_terraform. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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