tor-dice-docker

TOR-themed dice roller — Go server with embedded Svelte SPA. Calls rpg-dice-mcp over MCP for the actual roll resolution.

One binary, one container, one pod. The browser only ever talks to this server (same-origin, no CORS). Inside the Go process, an MCP client speaks Streamable HTTP to rpg-dice-mcp for roll, roll_tor_check, and roll_tor_combat.

Tracked: dvystrcil/homelab#262.

Architecture

┌─────────────────────────────────────┐
│  tor-dice (this repo)               │
│                                     │
│  GET  /            embed.FS         │ ← Svelte index.html + js/css
│  GET  /assets/*    embed.FS         │
│  POST /api/roll              ──┐    │ ← REST endpoints translate to
│  POST /api/roll_tor_check    ──┼─→  │   MCP CallTool() over Streamable
│  POST /api/roll_tor_combat   ──┘    │   HTTP (one long-lived session)
└─────────────────────────────────────┘
              │
              ▼ MCP / HTTP
┌─────────────────────────────────────┐
│  rpg-dice-mcp (separate service)    │
│  POST /mcp                          │
└─────────────────────────────────────┘

REST endpoints default format=html_tor so the response includes a ready-to-render formatted field with <span class="fdie7">7</span>-style dice spans. The Svelte SPA uses {@html result.formatted} for the rendered dice faces, with .fdie*/.sdie* CSS classes loading background images from un-tor.github.io.

Layout

.
├── main.go                       Go entrypoint + //go:embed all:web/dist
├── internal/
│   ├── server/server.go          HTTP server (REST + embed.FS)
│   ├── server/server_test.go
│   ├── mcpclient/client.go       MCP client wrapper (Streamable HTTP)
│   └── mcpclient/client_test.go
├── web/                          Svelte SPA source
│   ├── package.json
│   ├── vite.config.js
│   ├── index.html
│   └── src/
│       ├── App.svelte
│       ├── main.js
│       ├── app.css
│       ├── lib/
│       │   ├── api.js            fetch() wrappers
│       │   └── history.js        localStorage
│       └── components/
│           ├── SkillCheck.svelte
│           ├── CombatRoll.svelte
│           ├── GenericRoll.svelte
│           └── RollHistory.svelte
├── Dockerfile                    Multi-stage: vite build → go build → scratch
└── .github/workflows/
    ├── build.yaml                Tests + :dev image push on push to main
    └── docker-release.yaml       Promote :dev to :v* on GH release

Local development

The Svelte SPA can run against the Go server via Vite's proxy (defined in vite.config.js). One terminal runs Go, the other runs Vite:

# Terminal 1 — Go server (listens on :8080)
TOR_DICE_MCP_URL=http://localhost:8081/mcp go run .

# Terminal 2 — Svelte dev (listens on :5173, proxies /api → :8080)
cd web && npm install && npm run dev

For an end-to-end smoke test without an in-cluster rpg-dice-mcp, run a local one:

# Terminal 3 — rpg-dice-mcp
cd ../rpg-dice-mcp-docker
go run . --http=:8081

Building the production image

docker build -t tor-dice:dev .
docker run --rm -p 8080:8080 \
  -e TOR_DICE_MCP_URL=http://rpg-dice-mcp.example.com/mcp \
  tor-dice:dev

Configuration

Tests

go test -cover ./...

• internal/server: HTTP handlers tested against a fake DiceClient interface (89% coverage)
• internal/mcpclient: round-trip tests against an in-memory MCP server using the SDK's own NewStreamableHTTPHandler (74% coverage)

License

MIT. Dice-face PNGs and Aniron / InitialRing fonts © their respective creators, sourced from un-tor.github.io.