Linkerd2 MCP

⚠️ This project is a Work In Progress (WIP) and is still under active development. Features and APIs may change at any time.

ℹ️ The vast majority of this project has been built with the help of AI agents.

This project aims to expose a Model Context Protocol (MCP) server, enabling you to "talk" to your Linkerd2 service mesh. By building on top of Linkerd and Linkerd-viz, it provides an API for fetching high-level aggregated mesh data and for making changes—such as applying authorization policy updates—directly to your mesh.

A lightweight, fault-tolerant control plane for Linkerd-powered service meshes, exposing a gRPC MCP API for mesh introspection and safe policy mutation.

Project Structure

cmd/
  mcp-server/      → main.go (MCP API server)
  collector/       → main.go (Collector)
proto/             → *.proto + buf.yaml (gRPC contracts)
internal/
  graph/           → in-memory mesh model
  redis/           → Redis helpers (snapshot, delta, election)
docs/              → project docs
helm/              → chart/
Makefile           → convenience commands

Getting Started

Prerequisites

• Go 1.22+
• Docker or Podman
• kubectl 1.30+
• kind (for local k8s)
• Linkerd CLI 2.15+
• Prometheus (comes with Linkerd viz)
• Buf CLI 1.29+
• Helm 3.14+

Build

go build -o bin/collector ./cmd/collector
go build -o bin/mcp-server ./cmd/mcp-server

Running End-to-End (local kind cluster)

1. Start a kind cluster and install Linkerd + Prometheus:

   kind create cluster --name mcp-dev
   linkerd install | kubectl apply -f -
   linkerd viz install | kubectl apply -f -
   linkerd check
   

2. Deploy Redis (Valkey) and the MCP stack (see helm/ for chart):

   helm install mcp ./helm --namespace mcp --create-namespace --set redis.enabled=true
   

3. Port-forward MCP server and test the gRPC API:

   kubectl -n mcp port-forward svc/mcp 10900:10900
   grpcurl -plaintext localhost:10900 mcp.v1.MeshContext/GetMeshGraph
   

4. Apply a policy mutation via gRPC:

   grpcurl -plaintext -d '{"namespace":"default","name":"allow-foo","json_spec":"{\"foo\": \"bar\"}"}' localhost:10900 mcp.v1.MeshContext/ApplyAuthorizationPolicy
   

5. Verify AuthorizationPolicy CRs in the cluster:

   kubectl get authorizationpolicies.policy.linkerd.io -A
   

Development Workflow

• Edit proto contracts in proto/, run buf lint
• Implement business logic in cmd/ and internal/
• Use kind and helm for local testing
• Run unit tests: go test ./...
• See docs/progress.md for current status and next steps

Roadmap

• Integration testing and error handling
• Helm chart, CI/CD, documentation
• E2E tests and further enhancements

License

Apache 2.0