# sap-mcp-bridge — build sources

This directory contains the Docker build context for the
**`git.alexzaw.dev/alexz/sap-mcp-bridge`** image that the Runtipi app
references. The same files are mirrored under
`~/projects/sap-mcp-bridge/` so you can iterate on the image outside
the Runtipi tree if you prefer; treat the two locations as
copies-in-sync.

## Files

| File           | Role                                                                                |
| -------------- | ----------------------------------------------------------------------------------- |
| `Dockerfile`   | Node 24 + nginx + gosu + tini, installs 5 MCP servers + supergateway globally.      |
| `entrypoint.sh`| Boots as root → chowns `/workspace` → drops to `mcp` via gosu → launches 5 gateways on 127.0.0.1:9001–9005 → execs nginx on :8080. |
| `nginx.conf`   | Path-prefixed reverse proxy (`/cap/mcp`, `/abap/mcp`, …) with SSE/streaming-safe defaults (no buffering, 24h timeouts). |
| `build.sh`     | `docker build && docker push` to `git.alexzaw.dev/alexz/sap-mcp-bridge:<tag>`.       |

## How it works

The MCP servers are stdio-only. `supergateway` wraps each one as a
small HTTP server speaking the MCP "Streamable HTTP" transport. Each
gateway binds its own port (9001–9005) on the loopback interface,
inside the container only. An internal **nginx** is the only thing
that listens on the EXPOSEd port (8080) and routes requests by URL
path:

```
8080/cap/mcp     -> 127.0.0.1:9001/mcp
8080/abap/mcp    -> 127.0.0.1:9002/mcp
8080/odata/mcp   -> 127.0.0.1:9003/mcp
8080/ui5/mcp     -> 127.0.0.1:9004/mcp
8080/fiori/mcp   -> 127.0.0.1:9005/mcp
8080/healthz     -> 127.0.0.1:9001/healthz   (aggregate probe)
```

This single-port design is what makes the container Runtipi-deployable
behind Traefik, which only routes one port per app.

## Build & push

```bash
cd /etc/runtipi/repos/runtipi/apps/sap-mcp-bridge/build
./build.sh                              # builds + pushes :latest
IMAGE_TAG=1.0.0 ./build.sh              # tag a specific version
./build.sh --no-cache                   # forwarded to docker build
```

You must be logged in to the Gitea Docker registry:

```bash
docker login git.alexzaw.dev
```

## Deploy to Runtipi

After `build.sh` succeeds:

```bash
cd /etc/runtipi/repos/runtipi
sudo git add apps/sap-mcp-bridge
sudo git commit -m "sap-mcp-bridge: <what changed>"
sudo git push origin main

cd /etc/runtipi
sudo ./runtipi-cli appstore update
sudo ./runtipi-cli app update sap-mcp-bridge:runtipi   # for an already-installed app
# (first time: install via the Runtipi dashboard so form fields are written)
```

## Local sanity check (no Runtipi)

```bash
docker run --rm -p 8080:8080 \
  -v "$PWD/workspace:/workspace" \
  git.alexzaw.dev/alexz/sap-mcp-bridge:latest

# In another terminal:
curl http://127.0.0.1:8080/                   # landing page lists endpoints
curl http://127.0.0.1:8080/healthz            # 200
curl http://127.0.0.1:8080/cap/healthz        # 200 once cap-js-mcp-server boots
```

## Image dependencies (pinned in the Dockerfile)

- Base: `node:24-bookworm-slim`
- `supergateway@latest`
- `@iflow-mcp/cap-js-mcp-server@latest`
- `@iflow-mcp/mcp-abap-adt@1.1.0`
- `@iflow-mcp/btp-sap-odata-to-mcp-server@1.0.0`
- `@ui5/mcp-server@0.2.11`
- `@sap-ux/fiori-mcp-server@0.6.49`
- OS packages: `tini ca-certificates curl nginx gosu`

Bump the pinned versions in `Dockerfile` then rebuild.