Background

Currently, the Dockerfile in the flagd-testbed repository uses a fixed base image for building the testbed image. In order to facilitate testing with custom or pipeline-built flagd images, we need the ability to specify a different base image when building the testbed container.

Proposal

• Modify the Dockerfile to accept an argument (e.g., FLAGD_BASE_IMAGE) allowing the user to specify a custom base image.
• Update any relevant documentation to explain how to use this new argument during the build process.

Motivation

This change will enable building the testbed image in the flagd pipelines using a base image created within the same pipeline, supporting more flexible and robust testing scenarios.

Acceptance Criteria

• The Dockerfile accepts a build argument for the base flagd image
• Documentation is updated to describe how to use the argument
• Backwards compatibility is maintained (defaults to current base image if not provided)

Feel free to suggest alternative approaches or raise concerns about the impact on current workflows.