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Custom image

Customizing the Docker Image Used by a Scenario/Platform

The docker driver supports using pre-built images and docker build -ing local customizations for each scenario's platform. The Docker image used by a scenario is governed by the following configuration items:

  1. platforms[*].image: Docker image name:tag to use as base image.

  2. platforms[*].pre_build_image: Whether to customize base image or use as-is1.

    • When true, use the specified platform[].image as-is.
    • When false, exec docker build to customize base image using either:
    • Dockerfile specified by platforms[*].dockerfile or
    • Dockerfile rendered from Dockerfile.j2 template (in scenario dir)

The Dockerfile.j2 template is generated at molecule init scenario-time when --driver-name is docker. The template can be customized as needed to create the desired modifications to the Docker image used in the scenario.

Note: platforms[*].pre_build_image defaults to true in each scenario's generated molecule.yml file.

  1. Implementation in molecule docker driver ↩