Terminology

CFngin

Blueprint

A python class that is responsible for creating a CloudFormation template. Usually this is built using troposphere.

config

A YAML config file that defines the stack definitions for all of the stacks you want CFNgin to manage.

context

Context is responsible for translating the values passed in via the command line and specified in the config to stacks.

environment

A set of variables that can be used inside the config, allowing you to slightly adjust configs based on which environment you are launching.

graph

A mapping of object name to set/list of dependencies.

A graph is constructed for each execution of CFNgin from the contents of the config file.

Example

  • stack1 depends on nothing.

  • stack2 depends on stack1

hook

These are python functions/methods that are executed before or after the action is taken.

lookup

A method for expanding values in the config at build time. By default lookups are used to reference Output values from other stacks within the same namespace.

namespace

A way to uniquely identify a stack. Used to determine the naming of many things, such as the S3 bucket where compiled templates are stored, as well as the prefix for stack names.

output

A CloudFormation Template concept. Stacks can output values, allowing easy access to those values. Often used to export the unique ID’s of resources that templates create. CFNgin makes it simple to pull outputs from one stack and then use them as a variable in another stack.

persistent graph

A graph that is persisted between CFNgin executions. It is stored in in the Stack S3 bucket.

provider

Provider that supports provisioning rendered blueprints. By default, an AWS provider is used.

stack

The resulting stack of resources that is created by CloudFormation when it executes a template. Each stack managed by CFNgin is defined by a stack definition in the config.

stack definition

Defines the stack you want to build, usually there are multiple of these in the config. It also defines the variables to be used when building the stack.

variable

Dynamic variables that are passed into stacks when they are being built. Variables are defined within the config.