Advanced Middleware Usage

Last updated 2026-10-07

This page shows how to keep specific paths out of the middleware and how to call Check directly for a custom response.

Skipping Paths

Health checks, metrics scrapes, and fixed-period polling build up regular intervals and rate counts, so keep them out:

func protect(sentry *golangIPSentry.IPGuardian, next http.Handler) http.Handler {
    guarded := sentry.HTTPMiddleware(next)
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        switch r.URL.Path {
        case "/healthz", "/metrics":
            next.ServeHTTP(w, r)
        default:
            guarded.ServeHTTP(w, r)
        }
    })
}

Calling Check Directly

When you need a custom response format (an HTML error page, for example):

func handler(sentry *golangIPSentry.IPGuardian) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        result := sentry.Check(r, w)
        if !result.Success {
            http.Error(w, http.StatusText(result.StatusCode), result.StatusCode)
            return
        }
        w.Write([]byte("OK"))
    }
}

IPGuardianResult.Error contains the client IP; check your privacy requirements before echoing it back to clients.

For the basic net/http and Gin setup, see Middleware.