CloudFormation modules are managed by 2 files:

  • a key/value environment file

  • a yaml file defining the stacks/templates/params.


Name these files in the form of ENV-REGION.env (e.g. dev-us-east-1.env) or ENV.env (e.g. dev.env):

# Namespace is used as each stack's prefix
# We recommend an (org/customer)/environment delineation
namespace: contoso-dev
environment: dev
customer: contoso
region: us-west-2
# The stacker bucket is the S3 bucket (automatically created) where templates
# are uploaded for deployment (a CloudFormation requirement for large templates)
stacker_bucket_name: stacker-contoso-us-west-2

Stack Config (yaml file)

These files can have any name ending in .yaml (they will be evaluated in alphabetical order):

# Note namespace/stacker_bucket_name being substituted from the environment
namespace: ${namespace}
stacker_bucket: ${stacker_bucket_name}

  myvpcstack:  # will be deployed as contoso-dev-myvpcstack
    template_path: templates/vpc.yaml
    # The enabled option is optional and defaults to true. You can use it to
    # enable/disable stacks per-environment (i.e. like the namespace
    # substitution above, but with the value of either true or false for the
    # enabled option here)
    enabled: true
    template_path: templates/vpcendpoint.yaml
    # variables map directly to CFN parameters; here used to supply the
    # VpcId output from the myvpcstack to the VpcId parameter of this stack
      VpcId: ${output myvpcstack::VpcId}

The config yaml supports many more features; see the full CFNgin documentation for more detail (e.g. stack configuration options, additional lookups in addition to output (e.g. SSM, DynamoDB))

Environment Values Via Runway Deployment/Module Options

In addition or in place of the environment file(s), deploy environment specific values can be provided via deployment and module options as parameters. It is recommended to use Lookups in the parameters section to assist in selecting the appropriate values for the deploy environment and/or region being deployed to but, this is not a requirement if the value will remain the same.

Top-level Runway Config


  - modules:
      - path: mycfnstacks
          namespace: contoso-${env DEPLOY_ENVIRONMENT}
          foo: bar
          some_value: ${var some_map.${env DEPLOY_ENVIRONMENT}}



  - parameters:
      namespace: contoso-${env DEPLOY_ENVIRONMENT}
      foo: bar
      some_value: ${var some_map.${env DEPLOY_ENVIRONMENT}}
      - mycfnstacks

In Module Directory

  namespace: contoso-dev
  foo: bar

(in runway.module.yml)