Rewrite in Go

[Copilot]

Go channels only work within a single process. The existing implementation couldn't share game state across multiple server instances, unlike Elixir's distributed PubSub.

Changes

Redis pub/sub integration (internal/pubsub/)

• Wrapper over redis/go-redis/v9 with graceful degradation
• Subscribes to game:* channels for cross-server updates
• Falls back to single-server mode if Redis unavailable

Hub modifications (internal/hub/hub.go)

• Stores game state in Redis (game_state:{gameID} keys)
• Publishes updates to Redis channels (game:{gameID})
• Loads games from Redis if not in local memory
• Forwards Redis messages to local WebSocket clients

Configuration (cmd/server/main.go)

• Added -redis and -redis-password flags
• Supports REDIS_URL and REDIS_PASSWORD env vars

Architecture

Server A                    Redis                    Server B
   |                          |                          |
   |-- Create game ---------> | (store game_state:ID)    |
   |                          |                          |
   |-- Player scores -------> | (publish game:ID) -----> |
   |                          |                          |
   |                      (subscribe game:*)             |
   |                          |                          |
   ↓                          ↓                          ↓
WebSocket clients      All servers sync        WebSocket clients

Usage

Single-server mode (default):

./bin/robot-race -addr :8080

Multi-server mode:

./bin/robot-race -addr :8080 -redis localhost:6379
./bin/robot-race -addr :8081 -redis localhost:6379

Players on different servers can now join and play in the same game instance.

Backward Compatibility

Fully backward compatible. Redis is optional - server runs in single-server mode without it. No breaking changes to existing code or APIs.

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💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more Copilot coding agent tips in the docs.