Method ServeHTTP

prod/botshed/module.go:184–227

(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler)

}

func (b *Botshed) ServeHTTP(w http.ResponseWriter, r *http.Request, next caddyhttp.Handler) error {
	if r.Method != http.MethodGet || !strings.HasPrefix(r.URL.Path, "/explain") {
		return next.ServeHTTP(w, r)
	}
	cmd := r.URL.Query().Get("cmd")
	bnPtr := b.basenames.Load()
	cannedPtr := b.canned.Load()
	if bnPtr == nil || cannedPtr == nil {
		b.bootPassthroughs.Add(1)
		return next.ServeHTTP(w, r)
	}
	if b.readyLogged.CompareAndSwap(false, true) {
		b.logger.Info("botshed: ready",
			zap.Uint64("boot_passthroughs", b.bootPassthroughs.Load()),
		)
	}
	bn := *bnPtr
	canned := *cannedPtr

	shed, hits := shouldShed(cmd, bn)
	if !shed {
		return next.ServeHTTP(w, r)
	}

	idx := fnv32(cmd) % uint32(len(canned))
	body := canned[idx]
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	w.Header().Set("Cache-Control", "public, max-age=86400")
	w.WriteHeader(http.StatusOK)
	_, _ = w.Write(body)

	cmdSnip := cmd
	if len(cmdSnip) > 80 {
		cmdSnip = cmdSnip[:80]
	}
	b.logger.Info("botshed: shed",
		zap.String("client_ip", clientIP(r)),
		zap.String("country", r.Header.Get("CF-IPCountry")),
		zap.String("cmd", cmdSnip),
		zap.Int("hits", hits),
		zap.Uint32("canned_idx", idx),
	)
	return nil
}

// shouldShed is the single source of truth for the detector decision.
// ServeHTTP and the unit tests both call through here so the rule cannot