guest@portfolio:~/posts/Go/Web Server

Middleware Without Magic

1 min read
#go #middleware #web
>> Series Navigation

Building Production Go Web Servers

  1. 1. ServeMux Foundations
  2. > 2. Middleware Without Magic
  3. 3. Timeouts and Graceful Shutdown
  4. 4. Logs, Metrics, and Traces

Middleware is just a function that accepts and returns an http.Handler.

The Shape

type Middleware func(http.Handler) http.Handler

func Chain(h http.Handler, m ...Middleware) http.Handler {
    for i := len(m) - 1; i >= 0; i-- {
        h = m[i](h)
    }
    return h
}

This keeps dependencies explicit while preserving standard-library compatibility.

Request IDs

Generate an ID at the edge, store it in context, and write it to every log line produced during the request.

Recovery

Panic recovery should be the last safety net, not an error handling strategy. Log the panic, return a generic 500, and keep sensitive details out of the response.