func (l Logger) ServeHTTP(w http.ResponseWriter, r *http.Request) (int, error) {
for _, rule := range l.Rules {
if httpserver.Path(r.URL.Path).Matches(rule.PathScope) {
// Record the response
responseRecorder := httpserver.NewResponseRecorder(w)
// Attach the Replacer we'll use so that other middlewares can
// set their own placeholders if they want to.
rep := httpserver.NewReplacer(r, responseRecorder, CommonLogEmptyValue)
responseRecorder.Replacer = rep
// Bon voyage, request!
status, err := l.Next.ServeHTTP(responseRecorder, r)
if status >= 400 {
// There was an error up the chain, but no response has been written yet.
// The error must be handled here so the log entry will record the response size.
if l.ErrorFunc != nil {
l.ErrorFunc(responseRecorder, r, status)
} else {
// Default failover error handler
responseRecorder.WriteHeader(status)
fmt.Fprintf(responseRecorder, "%d %s", status, http.StatusText(status))
}
status = 0
}
// Write log entry
rule.Log.Println(rep.Replace(rule.Format))
return status, err
}
}
return l.Next.ServeHTTP(w, r)
}
func TestReverseProxy(t *testing.T) {
log.SetOutput(ioutil.Discard)
defer log.SetOutput(os.Stderr)
var requestReceived bool
backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
requestReceived = true
w.Write([]byte("Hello, client"))
}))
defer backend.Close()
// set up proxy
p := &Proxy{
Next: httpserver.EmptyNext, // prevents panic in some cases when test fails
Upstreams: []Upstream{newFakeUpstream(backend.URL, false)},
}
// create request and response recorder
r, err := http.NewRequest("GET", "/", nil)
if err != nil {
t.Fatalf("Failed to create request: %v", err)
}
w := httptest.NewRecorder()
p.ServeHTTP(w, r)
if !requestReceived {
t.Error("Expected backend to receive request, but it didn't")
}
// Make sure {upstream} placeholder is set
rr := httpserver.NewResponseRecorder(httptest.NewRecorder())
rr.Replacer = httpserver.NewReplacer(r, rr, "-")
p.ServeHTTP(rr, r)
if got, want := rr.Replacer.Replace("{upstream}"), backend.URL; got != want {
t.Errorf("Expected custom placeholder {upstream} to be set (%s), but it wasn't; got: %s", want, got)
}
}