func fixHostInProxyDirector()

in proxy/lib/proxy/proxy.go [443:466]

• 14 lines of code
• 4 McCabe index (conditional complexity)

func fixHostInProxyDirector(r *http.Request, host string) {
	// Workaround for golang issue https://github.com/golang/go/issues/28168.
	// Because golang ReverseProxy is using req.Host if it is not empty to make
	// the request to backend. But setting req.Host may also overwrite the Host
	// in the header, depends on http/1 or http/2. https://golang.org/pkg/net/http/#Request
	// In this func, we copy the host to header Host and X-Forwarded-Host for more
	// footprint and we set the X-Forwarded-Proto header if not set, then overwrite
	// the req.Host with req.URL.Host because req.URL.Host has set by defaultDirector.
	// This workaround will not break even golang ReverseProxy fix this issue.
	// In Go 1.20, the X-Forwarded-Host and X-Forwarded-Proto headers are set by
	// default (see https://github.com/golang/go/issues/50465)
	if len(r.Header.Get("X-Forwarded-Host")) == 0 {
		r.Header.Set("X-Forwarded-Host", host)
	}
	if len(r.Header.Get("X-Forwarded-Proto")) == 0 {
		if r.TLS == nil {
			r.Header.Set("X-Forwarded-Proto", "http")
		} else {
			r.Header.Set("X-Forwarded-Proto", "https")
		}
	}
	r.Header.Set("Host", host)
	r.Host = r.URL.Host
}