Backstage Roadmap Plugin Backend

This is the backend part of the Roadmap Plugin for Backstage, providing API endpoints to manage a public product roadmap with features, voting, and comments.

Architecture

This plugin follows a layered architecture with clear separation of concerns:

1. Database Layer

• RoadmapDatabaseClient: Handles direct database operations through Knex
• Uses transactions for all write operations to ensure data consistency
• Maps database errors to Backstage's error types for consistent error handling

2. Service Layer

• Implements business logic and validation rules
• Services include:
  • FeatureService: Feature management and validation
  • CommentService: Comment creation and retrieval
  • VoteService: Vote toggling and counting
  • PermissionService: Authorization and permission checks

3. Route Layer

• RESTful API endpoints that connect to frontend
• Routes include:
  • /features: CRUD operations for roadmap items
  • /comments: Add and retrieve comments for features
  • /votes: Toggle votes and get vote counts
  • /permissions: Check user permissions

4. Error Handling

• Uses Backstage's built-in error types and middleware
• Errors bubble up through layers and are handled centrally
• Provides consistent error responses with appropriate HTTP status codes

API Endpoints

Features

• GET /features/board-config: Resolved board columns (labels, visibility, retention settings) and UI capability flags for the active datasource.
• GET /features: Roadmap features for the board. With the database datasource, the list is filtered server-side using merged board config: hidden columns (visible: false) are omitted, and per-status retention hides stale items from this response. GitLab mode returns the existing issue list (no retention filtering added server-side).
• GET /features?includeBeyondRetention=true: Database only. Same column-visibility rules as the default list, but items past their retention window are included. Ignored when roadmap.source is gitlab.
• POST /features: Create a new feature suggestion
• GET /features/:id: Get a specific feature
• PUT /features/:id/status: Update feature status (admin only)
• PUT /features/:id: Update title and/or description (database only; admins always; non-admins only when they are the author and the feature is Suggested). Returns 403 for GitLab.
• DELETE /features/:id: Delete a feature (database only; admin, or author on Suggested). Returns 403 for GitLab.
• PUT /features/reorder: Reorder features within a status column (database, admin). Returns 403 for GitLab.

Comments

• GET /comments?featureId=123: Get comments for a feature
• POST /comments: Add a comment to a feature
• DELETE /comments/:commentId: Delete a comment (database, admin). Returns 403 for GitLab.

Votes

• POST /votes/:featureId: Toggle a vote on a feature
• GET /votes/:featureId/count: Get vote count for a feature
• GET /votes/counts?ids=123,456: Get vote counts for multiple features
• GET /votes/:featureId/user: Check if current user has voted

Permissions

• GET /permissions/check-admin: Check if current user is an admin

Development

Board configuration (app-config.yaml)

Optional roadmap.columns merges with built-in defaults. Each entry may set:

• status: One of the FeatureStatus values (Suggested, Planned, InProgress, Completed, Declined).
• title: Column label shown in the UI.
• visible: When false, features in that status are omitted from list endpoints (default board keeps In Progress hidden).
• retentionDays / retentionAnchor (created | updated): Database list filtering only; default list excludes older items; includeBeyondRetention=true opts in to the full set (still respecting hidden columns).

GitLab datasource freeze

When roadmap.source is gitlab, behavior stays limited to what the GitLab integration already supported: read/list, create feature and comment, voting, and admin status changes via labels. New capabilities (title/description edit, deletes, creator self-service edit/delete, reorder, retention and includeBeyondRetention) are not implemented for GitLab; related routes return 403 Not allowed and the frontend hides those actions based on GET /features/board-config capabilities.

Database Schema

The plugin sets up three main tables:

• features: Roadmap items with title, description, status, board_position (ordering within a status), etc.
• comments: User comments on features
• votes: User votes on features with unique constraint

Permission Model

• Uses Backstage's permission framework
• Allows configuration of admin users through app-config.yaml
• Supports both config-based permissions and Backstage's permission framework

Error Handling Strategy

This plugin follows Backstage's error handling patterns:

• InputError: For validation failures (400 errors)
• NotFoundError: When resources don't exist (404 errors)
• NotAllowedError: For authorization failures (403 errors)
• ConflictError: For database conflicts (409 errors)

Errors bubble up through layers to be handled by Backstage's middleware.