fix flaky unit test (#2749)

Signed-off-by: David Fridrich <fridrich.david19@gmail.com>

pkg/docker/creds/credentials_test.go

@@ -92,7 +92,7 @@ func TestCheckAuth(t *testing.T) {
 		incorrectPwd = "badpwd"
 	)
 
-	localhost, localhostTLS := startServer(t, uname, pwd)
+	localhost, localhostTLS, cert := startServer(t, uname, pwd)
 
 	_, portTLS, err := net.SplitHostPort(localhostTLS)
 	if err != nil {
@@ -132,7 +132,6 @@ func TestCheckAuth(t *testing.T) {
 			},
 			wantErr: false,
 		},
-
 		{
 			name: "correct credentials non-localhost",
 			args: args{
@@ -170,7 +169,30 @@ func TestCheckAuth(t *testing.T) {
 				Username: tt.args.username,
 				Password: tt.args.password,
 			}
-			if err := creds.CheckAuth(tt.args.ctx, tt.args.registry+"/someorg/someimage:sometag", c, http.DefaultTransport); (err != nil) != tt.wantErr {
+			// create trusted certificates pool and add our certificate
+			certPool := x509.NewCertPool()
+			certPool.AddCert(cert)
+
+			// client transport with the certificate
+			transport := &http.Transport{
+				TLSClientConfig: &tls.Config{
+					RootCAs: certPool,
+				},
+			}
+
+			dialer := &net.Dialer{}
+
+			transport.DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+				h, p, err := net.SplitHostPort(addr)
+				if err != nil {
+					return nil, err
+				}
+				if h == "test.io" {
+					h = "localhost"
+				}
+				return dialer.DialContext(ctx, network, net.JoinHostPort(h, p))
+			}
+			if err := creds.CheckAuth(tt.args.ctx, tt.args.registry+"/someorg/someimage:sometag", c, transport); (err != nil) != tt.wantErr {
 				t.Errorf("CheckAuth() error = %v, wantErr %v", err, tt.wantErr)
 			}
 		})
@@ -179,52 +201,15 @@ func TestCheckAuth(t *testing.T) {
 
 func TestCheckAuthEmptyCreds(t *testing.T) {
 
-	localhost, _ := startServer(t, "", "")
+	localhost, _, _ := startServer(t, "", "")
 	err := creds.CheckAuth(context.Background(), localhost+"/someorg/someimage:sometag", docker.Credentials{}, http.DefaultTransport)
 	if err != nil {
 		t.Error(err)
 	}
 }
 
-func startServer(t *testing.T, uname, pwd string) (addr, addrTLS string) {
-	// TODO: this should be refactored to use OS-chosen ports so as not to
-	// fail when a user is running a function on the default port.)
-	listener, err := net.Listen("tcp", "localhost:0")
-	if err != nil {
-		t.Fatal(err)
-	}
-	addr = listener.Addr().String()
-
-	listenerTLS, err := net.Listen("tcp", "localhost:0")
-	if err != nil {
-		t.Fatal(err)
-	}
-	addrTLS = listenerTLS.Addr().String()
-
-	handler := http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
-		if uname == "" || pwd == "" {
-			if req.Method == http.MethodPost {
-				resp.WriteHeader(http.StatusCreated)
-			} else {
-				resp.WriteHeader(http.StatusOK)
-			}
-			return
-		}
-		// TODO add also test for token based auth
-		resp.Header().Add("WWW-Authenticate", "basic")
-		if u, p, ok := req.BasicAuth(); ok {
-			if u == uname && p == pwd {
-				if req.Method == http.MethodPost {
-					resp.WriteHeader(http.StatusCreated)
-				} else {
-					resp.WriteHeader(http.StatusOK)
-				}
-				return
-			}
-		}
-		resp.WriteHeader(http.StatusUnauthorized)
-	})
-
+// generate Certificates
+func generateCert(t *testing.T) (tls.Certificate, *x509.Certificate) {
 	var randReader io.Reader = rand.Reader
 
 	caPublicKey, caPrivateKey, err := ed25519.GenerateKey(randReader)
@@ -232,15 +217,13 @@ func startServer(t *testing.T, uname, pwd string) (addr, addrTLS string) {
 		t.Fatal(err)
 	}
 
-	ca := &x509.Certificate{
-		SerialNumber: big.NewInt(1),
-		Subject: pkix.Name{
-			CommonName: "localhost",
-		},
+	caTemplate := &x509.Certificate{
+		SerialNumber:          big.NewInt(1),
+		Subject:               pkix.Name{CommonName: "localhost"},
 		IPAddresses:           []net.IP{net.IPv4(127, 0, 0, 1), net.IPv6loopback},
 		DNSNames:              []string{"localhost", "test.io"},
 		NotBefore:             time.Now(),
-		NotAfter:              time.Now().AddDate(10, 0, 0),
+		NotAfter:              time.Now().AddDate(1, 0, 0),
 		IsCA:                  true,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth, x509.ExtKeyUsageServerAuth},
 		ExtraExtensions:       []pkix.Extension{},
@@ -248,72 +231,103 @@ func startServer(t *testing.T, uname, pwd string) (addr, addrTLS string) {
 		BasicConstraintsValid: true,
 	}
 
-	caBytes, err := x509.CreateCertificate(randReader, ca, ca, caPublicKey, caPrivateKey)
+	caBytes, err := x509.CreateCertificate(randReader, caTemplate, caTemplate, caPublicKey, caPrivateKey)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	ca, err = x509.ParseCertificate(caBytes)
+	ca, err := x509.ParseCertificate(caBytes)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	cert := tls.Certificate{
+	tls := tls.Certificate{
 		Certificate: [][]byte{caBytes},
 		PrivateKey:  caPrivateKey,
 		Leaf:        ca,
 	}
+	return tls, ca
+}
 
+func startServer(t *testing.T, uname, pwd string) (addr, addrTLS string, ca *x509.Certificate) {
+	// create a custom handler function
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		// no authentication required, empty creds
+		if uname == "" || pwd == "" {
+			if r.Method == http.MethodPost {
+				w.WriteHeader(http.StatusCreated)
+			} else {
+				w.WriteHeader(http.StatusOK)
+			}
+			return
+		}
+
+		w.Header().Add("WWW-Authenticate", "basic")
+		if u, p, ok := r.BasicAuth(); ok {
+			if u == uname && p == pwd {
+				if r.Method == http.MethodPost {
+					w.WriteHeader(http.StatusCreated)
+				} else {
+					w.WriteHeader(http.StatusOK)
+				}
+				return
+			}
+		}
+		w.WriteHeader(http.StatusUnauthorized)
+	})
+
+	// Setup certificates
+	// tls Cert for the TLS server (has ca as Leaf)
+	// x509 certificate which is its own CA for client
+	tlsCert, ca := generateCert(t)
+
+	// create Server config
 	server := http.Server{
 		Handler: handler,
 		TLSConfig: &tls.Config{
-			ServerName:   "localhost",
-			Certificates: []tls.Certificate{cert},
+			ServerName: "localhost",
+			// with the TLS certificate
+			Certificates: []tls.Certificate{tlsCert},
 		},
 	}
 
+	// non-TLS listener
+	listener, err := net.Listen("tcp", "localhost:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// TLS listener
+	listenerTLS, err := net.Listen("tcp", "localhost:0")
+	if err != nil {
+		t.Fatal(err)
+	}
+	addr = listener.Addr().String()
+	addrTLS = listenerTLS.Addr().String()
+
+	// listen for requests
 	go func() {
 		err := server.ServeTLS(listenerTLS, "", "")
-		if err != nil && !strings.Contains(err.Error(), "Server closed") {
+		if err != nil && err != http.ErrServerClosed {
 			panic(err)
 		}
 	}()
 
 	go func() {
 		err := server.Serve(listener)
-		if err != nil && !strings.Contains(err.Error(), "Server closed") {
+		if err != nil && err != http.ErrServerClosed {
 			panic(err)
 		}
 	}()
-	// make the testing CA trusted by default HTTP transport/client
-	oldDefaultTransport := http.DefaultTransport
-	newDefaultTransport := http.DefaultTransport.(*http.Transport).Clone()
-	http.DefaultTransport = newDefaultTransport
-	caPool := x509.NewCertPool()
-	caPool.AddCert(ca)
-	newDefaultTransport.TLSClientConfig.RootCAs = caPool
-	dc := newDefaultTransport.DialContext
-	newDefaultTransport.DialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
-		h, p, err := net.SplitHostPort(addr)
-		if err != nil {
-			return nil, err
-		}
-		if h == "test.io" {
-			h = "localhost"
-		}
-		addr = net.JoinHostPort(h, p)
-		return dc(ctx, network, addr)
-	}
-
+	// shutdown servers at cleanup
 	t.Cleanup(func() {
 		err := server.Shutdown(context.Background())
 		if err != nil {
 			t.Fatal(err)
 		}
-		http.DefaultTransport = oldDefaultTransport
 	})
 
-	return addr, addrTLS
+	return
 }
 
 const (