Demo Start the MCP Gateway

Welcome back. In this lesson you’ll start a local MCP (Machine Control Plane) gateway that exposes an MCP server as a streamable HTTP endpoint. This guide walks through the prerequisites, verifying your kubeconfig, exporting the environment variable, and running the gateway using npx supergateway to wrap the MCP Docker image.

Prerequisites

A valid kubeconfig and a kubectl context pointing to the intended cluster.
docker installed and running (used to run the mcp/kubernetes:latest image).
npx (comes with Node.js / npm) to run supergateway.
Export an environment variable pointing to the kubeconfig file so the MCP container can access cluster metadata and credentials.

Helpful references:

Verify kubectl context

Confirm your kubectl context is set to the cluster you want to use and list namespaces to ensure connectivity:

➜  ~ kubectl config current-context
kind-finops-cluster

➜  ~ kubectl get ns
NAME                 STATUS   AGE
airline              Active   32h
booking-api          Active   32h
default              Active   32h
flight-search        Active   32h
inventory            Active   32h
kube-node-lease      Active   32h
kube-public          Active   32h
kube-system          Active   32h
local-path-storage   Active   32h
payment              Active   32h

Export the kubeconfig file location

Most environments use the default kubeconfig path at $HOME/.kube/config. Export an environment variable that points to the kubeconfig file so it can be mounted into the MCP container:

➜  ~ export KUBECONFIG_FILE="${KUBECONFIG:-$HOME/.kube/config}"

Quickly verify the file exists and the variable is set:

➜  ~ test -f "$KUBECONFIG_FILE" && echo "Using $KUBECONFIG_FILE"
Using /Users/raghunandanask/.kube/config

Start the MCP gateway

We use the npm package supergateway (via npx) to run a gateway process that:

launches the MCP server inside Docker (mcp/kubernetes:latest),
connects the server’s STDIN/STDOUT to the gateway,
exposes a streamable HTTP endpoint for MCP requests.

Run the following command to start the gateway:

npx -y supergateway \
  --stdio "docker run --rm -i --network host --user 0:0 \
  -v ${KUBECONFIG_FILE}:/kubeconfig:ro -e KUBECONFIG=/kubeconfig \
  mcp/kubernetes:latest" \
  --outputTransport streamableHttp \
  --port 8000 \
  --healthEndpoint /healthz

Key options explained:

npx -y supergateway --stdio "<command>" — runs the MCP process and tunnels its STDIN/STDOUT to the gateway.
Docker run:
- -v ${KUBECONFIG_FILE}:/kubeconfig:ro mounts your kubeconfig into the container at /kubeconfig (read-only).
- -e KUBECONFIG=/kubeconfig sets the environment variable inside the container so the MCP server uses the mounted kubeconfig.
- mcp/kubernetes:latest is the MCP server image.
--outputTransport streamableHttp instructs the gateway to use a single HTTP connection that can stream JSON chunks in the response.
--healthEndpoint /healthz enables the gateway health check endpoint.
--port 8000 chooses the gateway listening port.

Streamable HTTP uses a single HTTP request/response where the response can be streamed incrementally (JSON chunks). This is a convenient transport for local MCP experimentation. An alternative transport is Server-Sent Events (SSE).

Expected output

When the gateway starts successfully you should see output similar to:

[supergateway] Starting...
[supergateway] Supergateway is supported by Supermachine (hosted MCPs) - https://supermachine.ai
[supergateway]  - outputTransport: streamableHttp
[supergateway] Running stateless server
[supergateway]  - Headers: (none)
[supergateway]  - port: 8000
[supergateway]  - stdio: docker run --rm -i --network host --user 0:0  -v /Users/raghunandanask/.kube/config:/kubeconfig:ro -e KUBECONFIG=/kubeconfig     mcp/kubernetes:latest
[supergateway]  - streamableHttpPath: /mcp
[supergateway]  - protocolVersion: 2024-11-05
[supergateway]  - CORS: disabled
[supergateway]  - Health endpoints: /healthz
[supergateway] Listening on port 8000
[supergateway] StreamableHttp endpoint: http://localhost:8000/mcp

Exposed endpoints

Endpoint	Purpose	Example
`/healthz`	Health check for the gateway	`curl http://localhost:8000/healthz`
`/mcp`	Streamable HTTP MCP endpoint (accepts streamed MCP requests and returns JSON)	`http://localhost:8000/mcp`

Next steps

The MCP gateway is now running and ready to accept MCP-formatted requests over the streamable HTTP endpoint. Interacting with the MCP (for example, sending MCP requests with curl or a client) will be covered in later lessons. Additional references:

Introduction

The Problem Statement

Introduction to FinOps

Setting Up SkyLine Air Kubernetes Services

MCP Gateway for Kubernetes

LangChain MCP Agents

LLM Policy-Aware Label Audit

From Findings to Actionable Tickets

Demo Start the MCP Gateway

Prerequisites

Verify kubectl context

Export the kubeconfig file location

Start the MCP gateway

Expected output

Exposed endpoints

Next steps

Watch Video

​Prerequisites

​Verify kubectl context

​Export the kubeconfig file location

​Start the MCP gateway

​Expected output

​Exposed endpoints

​Next steps

Watch Video

Prerequisites

Verify kubectl context

Export the kubeconfig file location

Start the MCP gateway

Expected output

Exposed endpoints

Next steps