Kubernetes MCP Server

A Kubernetes Model Context Protocol (MCP) server that provides tools for interacting with Kubernetes clusters through a standardized interface.

Features

• API Resource Discovery: Get all available API resources in your Kubernetes cluster.
• Resource Listing: List resources of any type with optional namespace and label filtering.
• Resource Details: Get detailed information about specific Kubernetes resources.
• Resource Description: Get comprehensive descriptions of Kubernetes resources, similar to kubectl describe.
• Pod Logs: Retrieve logs from specific pods (optionally from a specific container, or all containers if unspecified).
• Node Metrics: Get resource usage metrics for specific nodes.
• Pod Metrics: Get CPU and Memory metrics for specific pods.
• Event Listing: List events within a namespace or for a specific resource.
• Resource Creation/Updating: Create new Kubernetes resources or update existing ones from a YAML or JSON manifest.
• Standardized Interface: Uses the MCP protocol for consistent tool interaction.
• Flexible Configuration: Supports different Kubernetes contexts and resource scopes.
• Multiple Modes: Run in stdio mode for CLI tools or sse mode for web applications.

Prerequisites

• Go 1.20 or later
• Access to a Kubernetes cluster
• kubectl configured with appropriate cluster access

Installation

1. Clone the repository:

   git clone https://github.com/reza-gholizade/k8s-mcp-server.git
   cd k8s-mcp-server

2. Install dependencies:

   go mod download

3. Build the server:

   go build -o k8s-mcp-server main.go

Usage

Starting the Server

The server can run in two modes, configurable via command-line flags or environment variables.

Stdio Mode (for CLI integrations)

This mode uses standard input/output for communication.

./k8s-mcp-server --mode stdio

Or using environment variables:

SERVER_MODE=stdio ./k8s-mcp-server

SSE Mode (for web applications)

This mode starts an HTTP server with Server-Sent Events support.

Default (port 8080):

./k8s-mcp-server --mode sse

Specify a port:

./k8s-mcp-server --mode sse --port 9090

Or using environment variables:

SERVER_MODE=sse SERVER_PORT=9090 ./k8s-mcp-server

If no mode is specified, it defaults to SSE on port 8080.

Using the Docker Image

You can also run the server using the pre-built Docker image from Docker Hub.

1. Pull the image:

   docker pull ginnux/k8s-mcp-server:latest

   You can replace latest with a specific version tag (e.g., 1.0.0).

2. Run the container:

   • SSE Mode (default behavior of the image):

     docker run -p 8080:8080 -v ~/.kube/config:/root/.kube/config:ro ginnux/k8s-mcp-server:latest

     This maps port 8080 of the container to port 8080 on your host and mounts your Kubernetes config read-only. The server will be available at http://localhost:8080. The image defaults to sse mode on port 8080.

   • Stdio Mode:

     docker run -i --rm -v ~/.kube/config:/root/.kube/config:ro ginnux/k8s-mcp-server:latest --mode stdio

     The -i flag is important for interactive stdio communication. --rm cleans up the container after exit.

   • Custom Port for SSE Mode:

     docker run -p 9090:9090 -v ~/.kube/config:/root/.kube/config:ro ginnux/k8s-mcp-server:latest --mode sse --port 9090

Using with Docker Compose

Create a docker-compose.yml file:

version: '3.8'
services:
  k8s-mcp-server:
    image: ginnux/k8s-mcp-server:latest # Or a specific version
    container_name: k8s-mcp-server
    ports:
      - "8080:8080" # Host:Container, adjust if using a different SERVER_PORT
    volumes:
      - ~/.kube:/root/.kube:ro # Mount kubeconfig read-only
    environment:
      - KUBECONFIG=/root/.kube/config
      - SERVER_MODE=sse # Default, can be 'stdio'
      - SERVER_PORT=8080 # Port for SSE mode
    restart: unless-stopped
    # To run in stdio mode with docker-compose, you might need to adjust 'ports',
    # add 'stdin_open: true' and 'tty: true', and potentially override the command.
    # For example, to force stdio mode:
    # command: ["--mode", "stdio"]

Then start with:

docker compose up -d

To see logs: docker compose logs -f k8s-mcp-server.

Making API Calls (SSE Mode)

Once the server is running in SSE mode, you can make JSON-RPC calls to its HTTP endpoint (e.g., / or /rpc depending on the mcp-go library's SSE server implementation):

curl -X POST -H "Content-Type: application/json" -d '{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getAPIResources",
  "params": {
    "arguments": {
      "includeNamespaceScoped": true,
      "includeClusterScoped": true
    }
  }
}' http://localhost:8080/

(Note: The exact endpoint for JSON-RPC over HTTP when using the SSE server might depend on the mcp-go library version. If / doesn't work, try /rpc.)

Available Tools

1. getAPIResources

Retrieves all available API resources in the Kubernetes cluster.

Parameters:

• includeNamespaceScoped (boolean, optional): Whether to include namespace-scoped resources (defaults to true).
• includeClusterScoped (boolean, optional): Whether to include cluster-scoped resources (defaults to true).

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getAPIResources",
  "params": {
    "arguments": {
      "includeNamespaceScoped": true,
      "includeClusterScoped": true
    }
  }
}

2. listResources

Lists all instances of a specific resource type.

Parameters:

• Kind (string, required): The kind of resource to list (e.g., "Pod", "Deployment").
• namespace (string, optional): The namespace to list resources from. If omitted, lists across all namespaces for namespaced resources (subject to RBAC).
• labelSelector (string, optional): Filter resources by label selector (e.g., "app=nginx,env=prod").

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "listResources",
  "params": {
    "arguments": {
      "Kind": "Pod",
      "namespace": "default",
      "labelSelector": "app=nginx"
    }
  }
}

3. getResource

Retrieves detailed information about a specific resource.

Parameters:

• kind (string, required): The kind of resource to get (e.g., "Pod", "Deployment").
• name (string, required): The name of the resource to get.
• namespace (string, optional): The namespace of the resource (required for namespaced resources).

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getResource",
  "params": {
    "arguments": {
      "kind": "Pod",
      "name": "nginx-pod",
      "namespace": "default"
    }
  }
}

4. describeResource

Describes a resource in the Kubernetes cluster, similar to kubectl describe.

Parameters:

• Kind (string, required): The kind of resource to describe (e.g., "Pod", "Deployment").
• name (string, required): The name of the resource to describe.
• namespace (string, optional): The namespace of the resource (required for namespaced resources).

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "describeResource",
  "params": {
    "arguments": {
      "Kind": "Pod",
      "name": "nginx-pod",
      "namespace": "default"
    }
  }
}

5. getPodsLogs

Retrieves the logs of a specific pod.

Parameters:

• Name (string, required): The name of the pod.
• namespace (string, required): The namespace of the pod.
• containerName (string, optional): The specific container name within the pod. If omitted:
  • If the pod has one container, its logs are fetched.
  • If the pod has multiple containers, logs from all containers are fetched and concatenated.

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getPodsLogs",
  "params": {
    "arguments": {
      "Name": "my-app-pod-12345",
      "namespace": "production",
      "containerName": "main-container"
    }
  }
}

6. getNodeMetrics

Retrieves resource usage metrics for a specific node.

Parameters:

• Name (string, required): The name of the node.

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getNodeMetrics",
  "params": {
    "arguments": {
      "Name": "worker-node-1"
    }
  }
}

7. getPodMetrics

Retrieves CPU and Memory metrics for a specific pod.

Parameters:

• namespace (string, required): The namespace of the pod.
• podName (string, required): The name of the pod.

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getPodMetrics",
  "params": {
    "arguments": {
      "namespace": "default",
      "podName": "my-app-pod-67890"
    }
  }
}

8. getEvents

Retrieves events for a specific namespace or resource.

Parameters:

• namespace (string, optional): The namespace to get events from. If omitted, events from all namespaces are considered (subject to RBAC).
• resourceName (string, optional): The name of a specific resource (e.g., a Pod name) to filter events for.
• resourceKind (string, optional): The kind of the specific resource (e.g., "Pod") if resourceName is provided.

Example (Namespace Events):

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getEvents",
  "params": {
    "arguments": {
      "namespace": "default"
    }
  }
}

Example (Resource Events):

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getEvents",
  "params": {
    "arguments": {
      "namespace": "production",
      "resourceName": "my-app-pod-12345",
      "resourceKind": "Pod"
    }
  }
}

9. createOrUpdateResource

Creates a new resource or updates an existing one from a YAML or JSON manifest.

Parameters:

• manifest (string, required): The YAML or JSON manifest of the resource.
• namespace (string, optional): The namespace in which to create/update the resource. If the manifest contains a namespace, this parameter can be used to override it. If not provided and the manifest doesn't specify one, "default" might be assumed or it might be an error depending on the resource type.

Example:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "createOrUpdateResource",
  "params": {
    "arguments": {
      "namespace": "default",
      "manifest": "apiVersion: v1
kind: Pod
metadata:
  name: my-new-pod
spec:
  containers:
  - name: nginx
    image: nginx:latest"
    }
  }
}

Development

Project Structure

.
├── .github/workflows/  # GitHub Actions workflows
│   └── docker-build-push.yml
├── handlers/           # Tool handlers and tool definitions
│   └── handlers.go
├── pkg/                # Internal packages
│   └── k8s/            # Kubernetes client implementation
├── tools/              # MCP Tool definitions
│   └── tools.go
├── main.go             # Server entry point
├── go.mod              # Go module definition
├── go.sum              # Go module checksums
├── Dockerfile          # Docker build definition
└── docker-compose.yml  # Docker Compose definition (example)

Adding New Tools

1. Define the Tool: In tools/tools.go, define a function that returns an mcp.Tool structure. This includes the tool's name, description, and input/output schemas.
2. Implement the Handler: In handlers/handlers.go, create a handler function. This function takes *k8s.Client as an argument and returns a function with the signature func(context.Context, mcp.ToolInput) (mcp.ToolOutput, error). This inner function will contain the logic for your tool.
3. Register the Tool: In main.go, add your new tool to the MCP server instance using s.AddTool(tools.YourToolDefinitionFunction(), handlers.YourToolHandlerFunction(client)).

Contributing

Contributions are welcome! Please see CONTRIBUTING.md for details on how to contribute to this project.

License

gholizade.net@gmail.com

This project is licensed under the MIT License - see the LICENSE file for details.

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