I couldn’t summarize this in a title (even with an LLM’s help):

I wanted to:

1. Run a Tailscale service discovery agent
2. On a Tailscale node outside of the Kubernetes cluster
3. Using Podman Quadlet
4. Accessing it from the Kubernetes Cluster using the Tailscale’s egress proxy
5. Accessing the proxy with a kube-prometheus ScrapeConfig
6. In order that Prometheus would scrape the container for Tailscale client metrics

Long-winded? Yes but I had an underlying need in running the Tailscale Service Discoovery remotely and this configuration helped me achieve that.

I was unable to find a Model Context Protocol (MCP) server implementation for Prometheus. I had a quiet weekend and so I’ve been writing one: prometheus-mcp-server.

I used the code from the MCP for gRPC Health Checking protocol that I wrote about previously as a guide.

I wrote a series of stdin and HTTP tests to have confidence that the service is working correctly but I had no MCP host.

I discovered that Visual Studio Code through its GitHub Copilot extension functions has a preview to use MCP servers i.e. function as an MCP host and access MCP servers.

Model Context Protocol (MCP) is “all the rage” these days.

I stumbled upon protoc-gen-go-mcp and think it’s an elegant application of two technologies: programmatically generating an MCP server from a gRPC protobuf.

I’m considering building an MCP server for Ackal but, thought I’d start with something simple: gRPC Health Checking protocol.

I was surprised to learn as I was doing this that there’s a new List (Add List method to gRPC Health service #143) added to grpc.health.v1.Health. My (Ackal) healthcheck server does not yet implement it (see later).