Kubernetes Tools MCP Server

Instructions

Implementation Reference

• src/k8stools/k8s_tools.py:79-117 (handler)

  The handler function implementing the core logic of the get_namespaces tool. It uses the Kubernetes CoreV1Api to list namespaces, calculates their age, and returns a list of NamespaceSummary pydantic models.
  def get_namespaces() -> list[NamespaceSummary]: """Return a summary of the namespaces for this Kubernetes cluster, similar to that returned by `kubectl get namespace`. Parameters ---------- None This function does not take any parameters. Returns ------- list of NamespaceSummary List of namespace summary objects. Each NamespaceSummary has the following fields: name : str Name of the namespace. status : str Status phase of the namespace. age : datetime.timedelta Age of the namespace (current time minus creation timestamp). Raises ------ K8sConfigError If unable to initialize the K8S API. K8sApiError If the API call to list namespaces fails. """ global K8S if K8S is None: K8S = _get_api_client() logging.info(f"get_namespaces()") namespaces = K8S.list_namespace().items now = datetime.datetime.now(datetime.timezone.utc) return [ NamespaceSummary(name=namespace.metadata.name, status=namespace.status.phase, age=now-namespace.metadata.creation_timestamp) for namespace in namespaces ]
• src/k8stools/k8s_tools.py:72-77 (schema)

  Pydantic model defining the output schema for each namespace returned by get_namespaces.
  class NamespaceSummary(BaseModel): """Summary information about a namespace, like returned by `kubectl get namespace`""" name: str status: str age: datetime.timedelta
• src/k8stools/mcp_server.py:46-65 (registration)

  Code in the MCP server that imports the TOOLS list (including get_namespaces) from k8s_tools or mock_tools, wraps each function into a FastMCP Tool object, and registers them in the FastMCP server instance.
  if not args.mock: from .k8s_tools import TOOLS else: from .mock_tools import TOOLS logging.warning(f"Using mock versions of the tools") wrapped_tools = [get_tool_for_function(fn) for fn in TOOLS] mcp = FastMCP( name="k8stools-"+args.transport, tools=wrapped_tools, streamable_http_path="/mcp", stateless_http=(args.transport == 'streamable-http'), host=args.host, port=args.port, log_level=args.log_level, debug=args.debug ) logging.debug(f"Settings are: {mcp.settings}") logging.info(f"Starting with {len(wrapped_tools)} tools on transport {args.transport}") # this starts the uvicorn server
• src/k8stools/k8s_tools.py:1101-1111 (registration)

  The TOOLS list that collects all tool handler functions, including get_namespaces, for use in MCP server registration.
  TOOLS = [ get_namespaces, get_node_summaries, get_pod_summaries, get_pod_container_statuses, get_pod_events, get_pod_spec, get_logs_for_pod_and_container, get_deployment_summaries, get_service_summaries ]
• src/k8stools/mcp_server.py:22-26 (helper)

  Helper function that converts a tool handler function into an MCP-compatible Tool object using FastMCP's Tool.from_function, enabling schema inference and structured output.
  def get_tool_for_function(fn) -> Tool: tool = Tool.from_function(fn, structured_output=True) #return_type = fn.__annotations__['return'] return tool