Environment variables


Similar to labels – we can specify environment variables that should be present in the container after running the image. We provide envs section for this.

Environment variables can be divided into two types:

  1. Information environment variables

    These are set and available in the image. This type of environment variables provide information to the image consumer. In most cases such environment variables should not be modified.

    It is possible to define a description for an information variable.

  2. Configuration environment variables

    This type of variables are used to define environment variables used to configure services inside running container. These environment variables are not set during image build time but can be set at run time.

    The primary difference to the above type is the lack of a value definition. Every configuration environment variable should provide an example usage (example) and short description (description).


Please note that you could have an environment variable with both a value and example set. This implies that this environment variable could be redefined.


Configuration environment variables (without a value key) are not generated to the build source (the Dockerfile). These can be used instead as a source for generating documentation.


Both forms support adding arbitrary additional keys. These are ignored by CEKit, but might be useful for documentation or other tooling.

    # Configuration env variables below
    # These will be added to container
    - name: "STI_BUILDER"
        value: "jee"
        value: "org.jboss.logmanager,jdk.nashorn.api"

    # Information env variables below
    # These will NOT be defined (there is no value)
        example: "myproject"
        description: "Clustering project namespace."
        example: "application=eap-app"
        description: "Clustering labels selector."

    # Both forms may have arbitrary additional metadata keys
        example: "application=eap-app"
        description: "Clustering labels selector."
        required: True
        execution-time: True