Query Syntax

<variable-name>[::<arg>=<arg-val>, ...]

Retrieve a value from an environment variable.

The value is retrieved from a copy of the current environment variables that is saved to the context object. These environment variables are manipulated at runtime by Runway to fill in additional values such as DEPLOY_ENVIRONMENT and AWS_REGION to match the current execution.


DEPLOY_ENVIRONMENT and AWS_REGION can only be resolved during the processing of a module. To ensure no error occurs when trying to resolve one of these in a Deployment definition, provide a default value.

If the Lookup is unable to find an environment variable matching the provided query, the default value is returned or a ValueError is raised if a default value was not provided.

New in version 1.4.0.


This Lookup supports all Common Lookup Arguments but, the following have limited or no effect:

  • region


  - modules:
      - path: sampleapp.cfn
          creator: ${env USER}
      ENVIRONMENT: ${env DEPLOY_ENVIRONMENT::default=default}