Feature Flag System - Overview

[tobi-bams]

Feature Flag System - Overview

General Overview

We aim to implement a dynamic feature flag system to control feature availability seamlessly. This system will include the following components:

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Backend

Database Schema

1. Feature Flags Table:

   • uuid (UUID): Unique identifier for the feature flag.
   • name (String): The name of the feature flag.
   • description (Text): A brief description of the feature flag.
   • enabled (Boolean): Status indicating whether the feature is enabled or disabled.

2. Endpoints Table:

   • uuid (UUID): Unique identifier for the endpoint.
   • path (String): The API endpoint path (e.g., /api/v1/chat).
   • feature_flag_uuid (UUID): Foreign key linking the endpoint to a feature flag.

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Middleware

A middleware will intercept every incoming request to the backend and:

1. Extract the requested endpoint's path.
2. Check if the path is associated with a feature flag in the database.
3. If associated:
   • Verify the feature flag's enabled status.
   • Enabled: Allow the request to proceed.
   • Disabled: Reject the request with an error message stating:
     "This feature is currently unavailable."

Future Plan:
In the future, we plan to integrate Redis as a caching layer to store feature flags and their associated endpoints. This will reduce database queries and enhance performance, especially for high-traffic endpoints. Redis will sync with the database to ensure real-time consistency whenever feature flags are updated.

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API Endpoints

1. Feature Flag Endpoints:

   • GET /feature_flags:
     Retrieves the list of feature flags and their associated endpoints.
     Accessible to admins and users.

   • POST /feature_flags:
     Allows admins to create a new feature flag.
     Takes the feature flag name, description, and an array of associated endpoints.
     Restricted to admin access.

   • PUT /feature_flags/{id}:
     Updates an existing feature flag, including its name, description, or status.
     Restricted to admin access.

   • DELETE /feature_flags/{id}:
     Deletes a feature flag and its associated endpoints.
     Restricted to admin access.

2. Endpoint Management:

   • POST /feature_flags/{feature_flag_id}/endpoints:
     Adds new endpoints to an existing feature flag.
     Requires the feature_flag_id and an array of endpoint paths to be provided.
     Restricted to admin access.

   • PUT /feature_flags/{feature_flag_id}/endpoints/{endpoint_id}:
     Updates an existing endpoint (e.g., modifies its path).
     Requires the feature_flag_id and the endpoint_id.
     Restricted to admin access.

   • DELETE /feature_flags/{feature_flag_id}/endpoints/{endpoint_id}:
     Deletes an endpoint linked to a specific feature flag.
     Requires the feature_flag_id and the endpoint_id.
     Restricted to admin access.

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Frontend

Feature Flag Synchronization

• On page load, the frontend will call the GET /feature_flags endpoint to retrieve the list of feature flags and their current statuses.
• The data will be stored in a global state (e.g., MobX).

Feature Visibility

• Based on the retrieved feature flag statuses, the frontend will dynamically determine whether to display certain features.

Example:

if (featureFlags.FF_Chat.enabled) {
    showChatComponent();
} else {
    hideChatComponent();
}

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Admin Dashboard

1. Feature Flags Tab:

   • Displays a table of all feature flags and their associated endpoints.
   • Visible only to super admins.

2. Create Feature Flag:

   • A button to open a modal or navigate to a form where admins can:
     • Add a feature flag name, description, and a list of endpoints.
   • Submit the form to store the feature flag in the backend.

3. Edit and Delete Feature Flags:

   • Each feature flag will have:
     • An Edit button to update its details or associated endpoints.
     • A Delete button to remove the feature flag and its associated endpoints.

4. Endpoint Management:

   • Add, edit, and delete endpoints associated with a feature flag using dedicated forms or modals.

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Summary

This enhanced feature flag system provides:

1. Dynamic control over feature availability.
2. Granular management of endpoints associated with feature flags.
3. A robust middleware to enforce feature restrictions at the backend.
4. Seamless synchronization between the backend and frontend for consistent feature visibility.
5. An admin-friendly interface for managing feature flags and their associated endpoints.

Future Scalability:
Redis integration will further enhance the system's performance by caching feature flags and their associations, minimizing database interactions, and supporting high traffic.

[MahtabBukhari]

@tobi-bams @humansinstitute please assign