Implement core HTTP MCP server

This commit implements the main HTTP server that wraps the Gitea MCP server with HTTP transport.

Architecture:
- GiteaMCPWrapper class manages subprocess communication with Gitea MCP
- Starlette ASGI application for HTTP endpoints
- JSON-RPC protocol bridge between HTTP and stdio transport

Features:
- Subprocess management: Starts/stops Gitea MCP server with proper env vars
- HTTP endpoints:
  - POST /tools/list - List available tools (with filtering)
  - POST /tools/call - Execute a tool
  - GET /health, /healthz, /ping - Health checks
- JSON-RPC communication via stdin/stdout pipes
- Tool filtering integration (blocks filtered tools at call time)
- Comprehensive error handling and logging
- Graceful startup/shutdown lifecycle

Integration:
- Uses GiteaSettings from config module (#11)
- Uses ToolFilter from filtering module (#12)
- Uses BearerAuthMiddleware and HealthCheckBypassMiddleware (#13)
- Passes Gitea config to wrapped MCP server via environment

Entry points:
- main() function for CLI execution
- create_app() factory for testing and custom configurations
- gitea-http-wrapper console script (defined in pyproject.toml)

This server can now be deployed in Docker (#15) and tested (#17).

Closes #14

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/gitea_http_wrapper/__init__.py

@@ -11,5 +11,7 @@ Architecture:
 - server.py: Main HTTP MCP server implementation
 """
 
+from .server import GiteaMCPWrapper, create_app, main
+
 __version__ = "0.1.0"
-__all__ = ["__version__"]
+__all__ = ["__version__", "GiteaMCPWrapper", "create_app", "main"]

src/gitea_http_wrapper/server.py

@@ -0,0 +1,309 @@
+"""HTTP MCP server implementation wrapping Gitea MCP."""
+
+import asyncio
+import json
+import logging
+import os
+import sys
+from pathlib import Path
+from typing import Any
+
+import uvicorn
+from mcp.server import Server
+from mcp.server.stdio import stdio_server
+from starlette.applications import Starlette
+from starlette.requests import Request
+from starlette.responses import JSONResponse
+from starlette.routing import Route
+
+from gitea_http_wrapper.config import GiteaSettings, load_settings
+from gitea_http_wrapper.filtering import ToolFilter
+from gitea_http_wrapper.middleware import (
+    BearerAuthMiddleware,
+    HealthCheckBypassMiddleware,
+)
+
+# Configure logging
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
+)
+logger = logging.getLogger(__name__)
+
+
+class GiteaMCPWrapper:
+    """
+    HTTP wrapper around the official Gitea MCP server.
+
+    This class manages:
+    1. Starting the Gitea MCP server as a subprocess with stdio transport
+    2. Proxying HTTP requests to the MCP server
+    3. Filtering tools based on configuration
+    4. Handling responses and errors
+    """
+
+    def __init__(self, settings: GiteaSettings):
+        """
+        Initialize the MCP wrapper.
+
+        Args:
+            settings: Configuration settings for Gitea and HTTP server.
+        """
+        self.settings = settings
+        self.tool_filter = ToolFilter(
+            enabled_tools=settings.enabled_tools_list,
+            disabled_tools=settings.disabled_tools_list,
+        )
+        self.process = None
+        self.reader = None
+        self.writer = None
+
+    async def start_gitea_mcp(self) -> None:
+        """
+        Start the Gitea MCP server as a subprocess.
+
+        The server runs with stdio transport, and we communicate via stdin/stdout.
+        """
+        logger.info("Starting Gitea MCP server subprocess")
+
+        # Set environment variables for Gitea MCP
+        env = os.environ.copy()
+        env.update(self.settings.get_gitea_mcp_env())
+
+        # Start the process
+        # Note: This assumes gitea-mcp-server is installed and on PATH
+        # In production Docker, this should be guaranteed
+        try:
+            self.process = await asyncio.create_subprocess_exec(
+                "gitea-mcp-server",
+                stdin=asyncio.subprocess.PIPE,
+                stdout=asyncio.subprocess.PIPE,
+                stderr=asyncio.subprocess.PIPE,
+                env=env,
+            )
+            self.reader = self.process.stdout
+            self.writer = self.process.stdin
+            logger.info("Gitea MCP server started successfully")
+        except FileNotFoundError:
+            logger.error("gitea-mcp-server not found in PATH")
+            raise RuntimeError(
+                "gitea-mcp-server not found. Ensure it's installed: pip install gitea-mcp-server"
+            )
+
+    async def stop_gitea_mcp(self) -> None:
+        """Stop the Gitea MCP server subprocess."""
+        if self.process:
+            logger.info("Stopping Gitea MCP server subprocess")
+            self.process.terminate()
+            await self.process.wait()
+            logger.info("Gitea MCP server stopped")
+
+    async def send_mcp_request(self, method: str, params: dict[str, Any]) -> dict[str, Any]:
+        """
+        Send a JSON-RPC request to the MCP server.
+
+        Args:
+            method: MCP method name (e.g., "tools/list", "tools/call").
+            params: Method parameters.
+
+        Returns:
+            JSON-RPC response from MCP server.
+
+        Raises:
+            RuntimeError: If MCP server is not running or communication fails.
+        """
+        if not self.writer or not self.reader:
+            raise RuntimeError("MCP server not started")
+
+        # Build JSON-RPC request
+        request = {
+            "jsonrpc": "2.0",
+            "id": 1,
+            "method": method,
+            "params": params,
+        }
+
+        # Send request
+        request_json = json.dumps(request) + "\n"
+        self.writer.write(request_json.encode())
+        await self.writer.drain()
+
+        # Read response
+        response_line = await self.reader.readline()
+        response = json.loads(response_line.decode())
+
+        # Check for JSON-RPC error
+        if "error" in response:
+            logger.error(f"MCP error: {response['error']}")
+            raise RuntimeError(f"MCP error: {response['error']}")
+
+        return response.get("result", {})
+
+    async def list_tools(self) -> dict[str, Any]:
+        """
+        List available tools from MCP server with filtering applied.
+
+        Returns:
+            Filtered tools list response.
+        """
+        response = await self.send_mcp_request("tools/list", {})
+        filtered_response = self.tool_filter.filter_tools_response(response)
+
+        logger.info(
+            f"Listed {len(filtered_response.get('tools', []))} tools "
+            f"(filter: {self.tool_filter.get_filter_stats()['mode']})"
+        )
+        return filtered_response
+
+    async def call_tool(self, tool_name: str, arguments: dict[str, Any]) -> dict[str, Any]:
+        """
+        Call a tool on the MCP server.
+
+        Args:
+            tool_name: Name of tool to call.
+            arguments: Tool arguments.
+
+        Returns:
+            Tool execution result.
+
+        Raises:
+            ValueError: If tool is filtered out.
+        """
+        # Check if tool is allowed
+        if not self.tool_filter.should_include_tool(tool_name):
+            raise ValueError(f"Tool '{tool_name}' is not available (filtered)")
+
+        logger.info(f"Calling tool: {tool_name}")
+        result = await self.send_mcp_request(
+            "tools/call",
+            {"name": tool_name, "arguments": arguments},
+        )
+        return result
+
+
+# Global wrapper instance
+wrapper: GiteaMCPWrapper | None = None
+
+
+async def health_check(request: Request) -> JSONResponse:
+    """Health check endpoint."""
+    return JSONResponse({"status": "healthy"})
+
+
+async def list_tools_endpoint(request: Request) -> JSONResponse:
+    """List available tools."""
+    try:
+        tools = await wrapper.list_tools()
+        return JSONResponse(tools)
+    except Exception as e:
+        logger.exception("Error listing tools")
+        return JSONResponse(
+            {"error": str(e)},
+            status_code=500,
+        )
+
+
+async def call_tool_endpoint(request: Request) -> JSONResponse:
+    """Call a tool."""
+    try:
+        body = await request.json()
+        tool_name = body.get("name")
+        arguments = body.get("arguments", {})
+
+        if not tool_name:
+            return JSONResponse(
+                {"error": "Missing 'name' field"},
+                status_code=400,
+            )
+
+        result = await wrapper.call_tool(tool_name, arguments)
+        return JSONResponse(result)
+    except ValueError as e:
+        # Tool filtered
+        return JSONResponse(
+            {"error": str(e)},
+            status_code=403,
+        )
+    except Exception as e:
+        logger.exception("Error calling tool")
+        return JSONResponse(
+            {"error": str(e)},
+            status_code=500,
+        )
+
+
+async def startup() -> None:
+    """Application startup handler."""
+    global wrapper
+    settings = load_settings()
+    wrapper = GiteaMCPWrapper(settings)
+    await wrapper.start_gitea_mcp()
+    logger.info(f"HTTP MCP server starting on {settings.http_host}:{settings.http_port}")
+
+
+async def shutdown() -> None:
+    """Application shutdown handler."""
+    global wrapper
+    if wrapper:
+        await wrapper.stop_gitea_mcp()
+
+
+# Define routes
+routes = [
+    Route("/health", health_check, methods=["GET"]),
+    Route("/healthz", health_check, methods=["GET"]),
+    Route("/ping", health_check, methods=["GET"]),
+    Route("/tools/list", list_tools_endpoint, methods=["POST"]),
+    Route("/tools/call", call_tool_endpoint, methods=["POST"]),
+]
+
+# Create Starlette app
+app = Starlette(
+    routes=routes,
+    on_startup=[startup],
+    on_shutdown=[shutdown],
+)
+
+
+def create_app(settings: GiteaSettings | None = None) -> Starlette:
+    """
+    Create and configure the Starlette application.
+
+    Args:
+        settings: Optional settings override for testing.
+
+    Returns:
+        Configured Starlette application.
+    """
+    if settings is None:
+        settings = load_settings()
+
+    # Add middleware
+    app.add_middleware(HealthCheckBypassMiddleware)
+    app.add_middleware(BearerAuthMiddleware, auth_token=settings.auth_token)
+
+    return app
+
+
+def main() -> None:
+    """Main entry point for the HTTP MCP server."""
+    settings = load_settings()
+
+    # Log filter configuration
+    filter_stats = ToolFilter(
+        enabled_tools=settings.enabled_tools_list,
+        disabled_tools=settings.disabled_tools_list,
+    ).get_filter_stats()
+    logger.info(f"Tool filtering: {filter_stats}")
+
+    # Run server
+    uvicorn.run(
+        "gitea_http_wrapper.server:app",
+        host=settings.http_host,
+        port=settings.http_port,
+        log_level="info",
+    )
+
+
+if __name__ == "__main__":
+    main()