refactor: move httptransport w/ logging to netxlite (#411)

Part of https://github.com/ooni/probe/issues/1505

internal/netxlite/http.go

@@ -0,0 +1,62 @@
+package netxlite
+
+import "net/http"
+
+// HTTPTransport is an http.Transport-like structure.
+type HTTPTransport interface {
+	// RoundTrip performs the HTTP round trip.
+	RoundTrip(req *http.Request) (*http.Response, error)
+
+	// CloseIdleConnections closes idle connections.
+	CloseIdleConnections()
+}
+
+// HTTPTransportLogger is an HTTPTransport with logging.
+type HTTPTransportLogger struct {
+	// HTTPTransport is the underlying HTTP transport.
+	HTTPTransport HTTPTransport
+
+	// Logger is the underlying logger.
+	Logger Logger
+}
+
+var _ HTTPTransport = &HTTPTransportLogger{}
+
+// RoundTrip implements HTTPTransport.RoundTrip.
+func (txp *HTTPTransportLogger) RoundTrip(req *http.Request) (*http.Response, error) {
+	host := req.Host
+	if host == "" {
+		host = req.URL.Host
+	}
+	req.Header.Set("Host", host) // anticipate what Go would do
+	return txp.logTrip(req)
+}
+
+// logTrip is an HTTP round trip with logging.
+func (txp *HTTPTransportLogger) logTrip(req *http.Request) (*http.Response, error) {
+	txp.Logger.Debugf("> %s %s", req.Method, req.URL.String())
+	for key, values := range req.Header {
+		for _, value := range values {
+			txp.Logger.Debugf("> %s: %s", key, value)
+		}
+	}
+	txp.Logger.Debug(">")
+	resp, err := txp.HTTPTransport.RoundTrip(req)
+	if err != nil {
+		txp.Logger.Debugf("< %s", err)
+		return nil, err
+	}
+	txp.Logger.Debugf("< %d", resp.StatusCode)
+	for key, values := range resp.Header {
+		for _, value := range values {
+			txp.Logger.Debugf("< %s: %s", key, value)
+		}
+	}
+	txp.Logger.Debug("<")
+	return resp, nil
+}
+
+// CloseIdleConnections implement HTTPTransport.CloseIdleConnections.
+func (txp *HTTPTransportLogger) CloseIdleConnections() {
+	txp.HTTPTransport.CloseIdleConnections()
+}

internal/netxlite/http_test.go

@@ -0,0 +1,108 @@
+package netxlite
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/apex/log"
+	"github.com/ooni/probe-cli/v3/internal/atomicx"
+	"github.com/ooni/probe-cli/v3/internal/iox"
+	"github.com/ooni/probe-cli/v3/internal/netxmocks"
+)
+
+func TestHTTPTransportLoggerFailure(t *testing.T) {
+	txp := &HTTPTransportLogger{
+		Logger: log.Log,
+		HTTPTransport: &netxmocks.HTTPTransport{
+			MockRoundTrip: func(req *http.Request) (*http.Response, error) {
+				return nil, io.EOF
+			},
+		},
+	}
+	client := &http.Client{Transport: txp}
+	resp, err := client.Get("https://www.google.com")
+	if !errors.Is(err, io.EOF) {
+		t.Fatal("not the error we expected")
+	}
+	if resp != nil {
+		t.Fatal("expected nil response here")
+	}
+}
+
+func TestHTTPTransportLoggerFailureWithNoHostHeader(t *testing.T) {
+	foundHost := &atomicx.Int64{}
+	txp := &HTTPTransportLogger{
+		Logger: log.Log,
+		HTTPTransport: &netxmocks.HTTPTransport{
+			MockRoundTrip: func(req *http.Request) (*http.Response, error) {
+				if req.Header.Get("Host") == "www.google.com" {
+					foundHost.Add(1)
+				}
+				return nil, io.EOF
+			},
+		},
+	}
+	req := &http.Request{
+		Header: http.Header{},
+		URL: &url.URL{
+			Scheme: "https",
+			Host:   "www.google.com",
+			Path:   "/",
+		},
+	}
+	resp, err := txp.RoundTrip(req)
+	if !errors.Is(err, io.EOF) {
+		t.Fatal("not the error we expected")
+	}
+	if resp != nil {
+		t.Fatal("expected nil response here")
+	}
+	if foundHost.Load() != 1 {
+		t.Fatal("host header was not added")
+	}
+}
+
+func TestHTTPTransportLoggerSuccess(t *testing.T) {
+	txp := &HTTPTransportLogger{
+		Logger: log.Log,
+		HTTPTransport: &netxmocks.HTTPTransport{
+			MockRoundTrip: func(req *http.Request) (*http.Response, error) {
+				return &http.Response{
+					Body: io.NopCloser(strings.NewReader("")),
+					Header: http.Header{
+						"Server": []string{"antani/0.1.0"},
+					},
+					StatusCode: 200,
+				}, nil
+			},
+		},
+	}
+	client := &http.Client{Transport: txp}
+	resp, err := client.Get("https://www.google.com")
+	if err != nil {
+		t.Fatal(err)
+	}
+	iox.ReadAllContext(context.Background(), resp.Body)
+	resp.Body.Close()
+}
+
+func TestHTTPTransportLoggerCloseIdleConnections(t *testing.T) {
+	calls := &atomicx.Int64{}
+	txp := &HTTPTransportLogger{
+		HTTPTransport: &netxmocks.HTTPTransport{
+			MockCloseIdleConnections: func() {
+				calls.Add(1)
+			},
+		},
+		Logger: log.Log,
+	}
+	txp.CloseIdleConnections()
+	if calls.Load() != 1 {
+		t.Fatal("not called")
+	}
+}

internal/netxlite/logger.go

@@ -4,4 +4,7 @@ package netxlite
 type Logger interface {
 	// Debugf formats and emits a debug message.
 	Debugf(format string, v ...interface{})
+
+	// Debug emits a debug message.
+	Debug(msg string)
 }