The sfn command can be invoked in two ways. The first is directly:

$ sfn --help

The second is via the knife plugin:

$ knife sparkleformation --help

Both invocations will generate the same result. The direct sfn command can be preferable as it does not require loading outside libraries nor does it traverse the filesystem loading plugins. Because of this, the direct command will generally be faster than the knife plugin.

Directory Structure

The sfn command utilizes the SparkleFormation library and supports template compilation. To use SparkleFormation, just create the directory structure within the local project working directory:

> tree
| |____dynamics
| |____components
| |____registry


Template Commands

These are the commands that support an orchestration template. By default, sfn does not enable the SparkleFormation integration. This means that any innvocation when a template is required must provide a path to the serialized document using the --file option.

To enable the SparkleFormation integration simply include the ---processing flag, or enable it via the configuration file: do
  processing true

When processing is enabled and no path is provided via the --file option, sfn will prompt for template selection allowing the user to choose from local templates, as well as any templates distributed in loaded SparklePacks.

Available template related commands:

  • sfn create
  • sfn plan
  • sfn update
  • sfn validate

The sfn command supports the advanced nesting functionality provided by the SparkleFormation library. There are two styles of nesting functionality available: shallow and deep. The required style can be set via the configuration file: do
  apply_nesting 'deep'

The default nesting functionality is "deep". To learn more about the nesting functionality please refer to the SparkleFormation nested stacks documentation.

When using nested stacks, a bucket is required for storage of the nested stack templates. sfn will automatically store nested templates into the defined bucket, but the bucket name must be provided and the bucket must exist. The bucket name can be defined within the configuration: do
  nesting_bucket 'my-nested-templates'

Stack Commands

These commands are used for inspection or removal of existing stacks:

  • sfn describe
  • sfn inspect
  • sfn diff
  • sfn events
  • sfn destroy

While the describe command is good for an overview of a stack contents (resources and outputs), the inspect command allows for deeper inspection of a given stack. The --attribute option allows access to the underlying data model that represents the given resource and can be inspected for information. The data modeling is provided by the miasma cloud library which can be referenced for supported methods available. As an example, given an AWS CloudFormation stack with a single EC2 resource, the inspect command can be used to provide all addresses associated with the instance:

$ sfn inspect my-stack --attribute ''