feat: add /health endpoint and switch to fastmcp 2.0

- Switch from mcp package to fastmcp>=2.0 for Streamable HTTP support
  - Fixes 405 Method Not Allowed for MCP clients like Gemini CLI
  - MCP endpoint now at /mcp (POST) instead of /sse (GET)
  - Removes MCP_ALLOWED_HOSTS (handled at reverse proxy level)

- Add /health endpoint for Docker health checks
  - Returns {"status": "ok"} (200) or {"status": "degraded"} (503)
  - Enables health checks without transport security issues

- Add curl to Docker image for health checks
- Add healthcheck config to docker-compose files
- Add test-health and test-mcp Makefile targets
- Update documentation

server.py

@@ -1,8 +1,11 @@
 import os
+import json
 import logging
 import httpx
-from mcp.server.fastmcp import FastMCP
-from mcp.server.transport_security import TransportSecuritySettings
+from fastmcp import FastMCP
+from starlette.applications import Starlette
+from starlette.responses import JSONResponse
+from starlette.routing import Route, Mount
 from dotenv import load_dotenv
 
 # Load environment variables
@@ -16,7 +19,6 @@ logger = logging.getLogger(__name__)
 KOMODO_URL = os.getenv("KOMODO_URL", "").rstrip("/")
 KOMODO_API_KEY = os.getenv("KOMODO_API_KEY", "")
 KOMODO_API_SECRET = os.getenv("KOMODO_API_SECRET", "")
-MCP_ALLOWED_HOSTS = os.getenv("MCP_ALLOWED_HOSTS", "localhost:*,127.0.0.1:*")
 
 
 class KomodoClient:
@@ -75,12 +77,9 @@ def _get_client() -> tuple[KomodoClient | None, dict | None]:
 
 
 # --- MCP Server ---
-transport_security = TransportSecuritySettings(
-    enable_dns_rebinding_protection=True,
-    allowed_hosts=[h.strip() for h in MCP_ALLOWED_HOSTS.split(",")],
-    allowed_origins=[],
-)
-mcp = FastMCP("Komodo MCP", transport_security=transport_security)
+# Note: Host validation is handled at the reverse proxy/ingress level
+# The /health endpoint bypasses this for Docker health checks
+mcp = FastMCP("Komodo MCP")
 
 
 # --- API Documentation Resource ---
@@ -143,63 +142,66 @@ def get_api_reference() -> str:
 
 
 # --- MCP Tools ---
+# Note: Return str (JSON) instead of dict to work around FastMCP/Gemini CLI
+# schema compatibility issue with additionalProperties
+
 @mcp.tool()
-def list_servers() -> dict:
+def list_servers() -> str:
     """Lists all servers (periphery nodes) connected to Komodo.
     
-    Returns server names, IDs, status, and system information.
+    Returns server names, IDs, status, and system information as JSON.
     """
     client, error = _get_client()
     if error:
-        return error
-    return client.read("ListServers")
+        return json.dumps(error)
+    return json.dumps(client.read("ListServers"))
 
 
 @mcp.tool()
-def list_deployments() -> dict:
+def list_deployments() -> str:
     """Lists all deployments (single container applications).
     
-    Deployments are Docker containers managed by Komodo.
+    Deployments are Docker containers managed by Komodo. Returns JSON.
     """
     client, error = _get_client()
     if error:
-        return error
-    return client.read("ListDeployments")
+        return json.dumps(error)
+    return json.dumps(client.read("ListDeployments"))
 
 
 @mcp.tool()
-def list_stacks() -> dict:
+def list_stacks() -> str:
     """Lists all stacks (docker-compose applications).
     
-    Stacks are multi-container applications defined by docker-compose files.
+    Stacks are multi-container applications defined by docker-compose files. Returns JSON.
     """
     client, error = _get_client()
     if error:
-        return error
-    return client.read("ListStacks")
+        return json.dumps(error)
+    return json.dumps(client.read("ListStacks"))
 
 
 @mcp.tool()
-def get_container_status(deployment: str) -> dict:
+def get_container_status(deployment: str) -> str:
     """Gets the status of a specific container.
     
     Args:
         deployment: Deployment name or ID
     
-    Returns container state, image, ports, and resource usage.
+    Returns container state, image, ports, and resource usage as JSON.
     """
     client, error = _get_client()
     if error:
-        return error
-    return client.read("GetDeploymentContainer", {"deployment": deployment})
+        return json.dumps(error)
+    return json.dumps(client.read("GetDeploymentContainer", {"deployment": deployment}))
 
 
 @mcp.tool()
 def komodo_api_call(
     endpoint: str,
     request_type: str,
-    params: dict = None
-) -> dict:
+    params: str = "{}"
+) -> str:
     """Execute a raw Komodo API call.
     
     Use the komodo://api-reference resource for available request types.
@@ -207,24 +209,57 @@ def komodo_api_call(
     Args:
         endpoint: API endpoint - 'read', 'write', or 'execute'
         request_type: Request type name (e.g., 'GetServer', 'Deploy', 'ListBuilds')
-        params: Request parameters as a dictionary
+        params: Request parameters as a JSON string (default: "{}")
     
     Examples:
-        - Get server: endpoint='read', request_type='GetServer', params={'server': 'my-server'}
-        - Deploy: endpoint='execute', request_type='Deploy', params={'deployment': 'my-app'}
-        - List builds: endpoint='read', request_type='ListBuilds', params={}
+        - Get server: endpoint='read', request_type='GetServer', params='{"server": "my-server"}'
+        - Deploy: endpoint='execute', request_type='Deploy', params='{"deployment": "my-app"}'
+        - List builds: endpoint='read', request_type='ListBuilds', params='{}'
     """
     client, error = _get_client()
     if error:
-        return error
+        return json.dumps(error)
     
     if endpoint not in ("read", "write", "execute"):
-        return {"error": f"Invalid endpoint '{endpoint}'. Use 'read', 'write', or 'execute'."}
+        return json.dumps({"error": f"Invalid endpoint '{endpoint}'. Use 'read', 'write', or 'execute'."})
+    
+    try:
+        parsed_params = json.loads(params) if params else {}
+    except json.JSONDecodeError as e:
+        return json.dumps({"error": f"Invalid JSON in params: {e}"})
     
     method = getattr(client, endpoint)
-    return method(request_type, params or {})
+    return json.dumps(method(request_type, parsed_params))
+
+
+# --- Health Check Endpoint ---
+async def health(request):
+    """Health check endpoint for Docker."""
+    client, error = _get_client()
+    if error:
+        return JSONResponse({"status": "degraded", "error": error["error"]}, status_code=503)
+    return JSONResponse({"status": "ok"})
+
+
+# --- ASGI Application ---
+def create_app():
+    """Create the ASGI application with health check and MCP routes."""
+    mcp_app = mcp.http_app()
+    
+    # Wrapper app: /health is standalone, everything else goes to MCP
+    # IMPORTANT: Must pass mcp_app.lifespan for task group initialization
+    routes = [
+        Route("/health", health, methods=["GET"]),
+        Mount("/", app=mcp_app),  # MCP handles /mcp endpoint
+    ]
+    
+    return Starlette(routes=routes, lifespan=mcp_app.lifespan)
+
+
+# Create the app instance for uvicorn
+app = create_app()
 
 
 if __name__ == "__main__":
     import uvicorn
-    uvicorn.run(mcp.sse_app, host="0.0.0.0", port=8000)
+    uvicorn.run(app, host="0.0.0.0", port=8000)