Backend: Use default devfile with golden image to create workspace if no devfile is present

MR - Use default devfile with golden image to create... (!171230 - merged)

Description

As per the plan in Provide default devfile for projects if not pre... (&14644 - closed) , use default devfile with golden image to create workspace if no .devfile.yaml is present in the root of the repository. The default devfile would be very simple.

e.g.

schemaVersion: 2.2.0
components:
  - name: development-environment
    attributes:
      gl/inject-editor: true
    container:
      image: "GOLDEN_IMAGE"

• Add a new settings in the settings module. This will be a string type. The value would be as follows (use a HEREDOC to define it inline)

schemaVersion: 2.2.0
components:
  - name: development-environment
    attributes:
      gl/inject-editor: true
    container:
      image: "registry.gitlab.com/gitlab-org/gitlab-build-images/workspace/ubuntu-22.04:go-1.22"

• Update devfile_fetcher.rb
  • If devfile_path is not null, fetch the value from the repository.
  • Else use the default value from the settings module.
• Rename devfile_ref to project_ref in the DB and the GraphQL and the codebase.
• make devfile_path nullable at DB, and also potentially remove validation (so far do not see)

Acceptance Criteria

• DB migration to make devfile_path nullable
• Update devfile_fetcher.rb to take in default devfile is needed
• Rename devfile_ref to project_ref in the DB and the GraphQL and the codebase.
• Add a new settings in the settings module.

Technical Requirements

NA

Design Requirements

NA

Impact Assessment

NA

User Story

NA