Implement --dump-headers and --dump-bodies debug flags

fs/loghttp.go

@@ -0,0 +1,54 @@
+// A logging http transport
+
+package fs
+
+import (
+	"log"
+	"net/http"
+	"net/http/httputil"
+)
+
+const separator = "------------------------------------------------------------"
+
+// An http transport which logs the traffic
+type loggedTransport struct {
+	wrapped http.RoundTripper
+	logBody bool
+}
+
+// NewLoggedTransport wraps the transport passed in and logs all roundtrips
+// including the body if logBody is set.
+func NewLoggedTransport(transport http.RoundTripper, logBody bool) *loggedTransport {
+	return &loggedTransport{
+		wrapped: transport,
+		logBody: logBody,
+	}
+}
+
+// CancelRequest cancels an in-flight request by closing its
+// connection. CancelRequest should only be called after RoundTrip has
+// returned.
+func (t *loggedTransport) CancelRequest(req *http.Request) {
+	if wrapped, ok := t.wrapped.(interface {
+		CancelRequest(*http.Request)
+	}); ok {
+		log.Printf("CANCEL REQUEST %v", req)
+		wrapped.CancelRequest(req)
+	}
+}
+
+// RoundTrip implements the RoundTripper interface.
+func (t *loggedTransport) RoundTrip(req *http.Request) (resp *http.Response, err error) {
+	buf, _ := httputil.DumpRequest(req, t.logBody)
+	log.Println(separator)
+	log.Println("HTTP REQUEST")
+	log.Println(string(buf))
+	log.Println(separator)
+	resp, err = t.wrapped.RoundTrip(req)
+	buf, _ = httputil.DumpResponse(resp, t.logBody)
+	log.Println(separator)
+	log.Println("HTTP RESPONSE")
+	log.Println(string(buf))
+	log.Println(separator)
+	return resp, err
+}