pass *url.URL to ConnectPacketBuilder

As per discussion in eclipse-paho#192 I've added URL as a parameter, and also an example on how to use it to extract password from URL

autopaho/auto.go

@@ -79,7 +79,7 @@ type ClientConfig struct {
 	WillMessage    *paho.WillMessage
 	WillProperties *paho.WillProperties
 
-	ConnectPacketBuilder func(*paho.Connect) *paho.Connect // called prior to connection allowing customisation of the CONNECT packet
+	ConnectPacketBuilder func(*paho.Connect, *url.URL) *paho.Connect // called prior to connection allowing customisation of the CONNECT packet
 
 	// DisconnectPacketBuilder - called prior to disconnection allowing customisation of the DISCONNECT
 	// packet. If the function returns nil, then no DISCONNECT packet will be passed; if nil a default packet is sent.
@@ -157,7 +157,7 @@ func (cfg *ClientConfig) SetWillMessage(topic string, payload []byte, qos byte,
 //
 // Deprecated: Set ConnectPacketBuilder directly instead. This function exists for
 // backwards compatibility only (and may be removed in the future).
-func (cfg *ClientConfig) SetConnectPacketConfigurator(fn func(*paho.Connect) *paho.Connect) bool {
+func (cfg *ClientConfig) SetConnectPacketConfigurator(fn func(*paho.Connect, *url.URL) *paho.Connect) bool {
 	cfg.ConnectPacketBuilder = fn
 	return fn != nil
 }
@@ -174,7 +174,7 @@ func (cfg *ClientConfig) SetDisConnectPacketConfigurator(fn func() *paho.Disconn
 
 // buildConnectPacket constructs a Connect packet for the paho client, based on staged configuration.
 // If the program uses SetConnectPacketConfigurator, the provided callback will be executed with the preliminary Connect packet representation.
-func (cfg *ClientConfig) buildConnectPacket(firstConnection bool) *paho.Connect {
+func (cfg *ClientConfig) buildConnectPacket(firstConnection bool, serverURL *url.URL) *paho.Connect {
 
 	cp := &paho.Connect{
 		KeepAlive:  cfg.KeepAlive,
@@ -206,7 +206,7 @@ func (cfg *ClientConfig) buildConnectPacket(firstConnection bool) *paho.Connect
 	}
 
 	if cfg.ConnectPacketBuilder != nil {
-		cp = cfg.ConnectPacketBuilder(cp)
+		cp = cfg.ConnectPacketBuilder(cp, serverURL)
 	}
 
 	return cp

autopaho/auto_test.go

@@ -413,7 +413,7 @@ func TestClientConfig_buildConnectPacket(t *testing.T) {
 	}
 
 	// Validate initial state
-	cp := config.buildConnectPacket(true)
+	cp := config.buildConnectPacket(true, nil)
 
 	if !cp.CleanStart {
 		t.Errorf("Expected Clean Start to be true")
@@ -434,7 +434,7 @@ func TestClientConfig_buildConnectPacket(t *testing.T) {
 	config.SetUsernamePassword("testuser", []byte("testpassword"))
 	config.SetWillMessage(fmt.Sprintf("client/%s/state", config.ClientID), []byte("disconnected"), 1, true)
 
-	cp = config.buildConnectPacket(false)
+	cp = config.buildConnectPacket(false, nil)
 	if cp.CleanStart {
 		t.Errorf("Expected Clean Start to be false")
 	}
@@ -470,16 +470,50 @@ func TestClientConfig_buildConnectPacket(t *testing.T) {
 	}
 
 	// Set an override method for the CONNECT packet
-	config.SetConnectPacketConfigurator(func(c *paho.Connect) *paho.Connect {
+	config.SetConnectPacketConfigurator(func(c *paho.Connect, u *url.URL) *paho.Connect {
 		delay := uint32(200)
 		c.WillProperties.WillDelayInterval = &delay
+		c.Username = u.User.Username()
+		p, _ := u.User.Password()
+		c.Password = []byte(p)
 		return c
 	})
 
-	cp = config.buildConnectPacket(false)
+	testUrl, _ := url.Parse("mqtt://mqtt_user:[email protected]:1883")
+	cp = config.buildConnectPacket(false, testUrl)
 
 	if *(cp.WillProperties.WillDelayInterval) != 200 { // verifies the override
 		t.Errorf("Will message Delay Interval did not match expected [200]: found [%v]", *(cp.Properties.WillDelayInterval))
 	}
+	if cp.Username != "mqtt_user" { // verifies the override
+		t.Errorf("username did not match expected [mqtt_user]: found [%v]", cp.Username)
+	}
+	if string(cp.Password) != "mqtt_pass" { // verifies the override
+		t.Errorf("password did not match expected [mqtt_pass]: found [%v]", string(cp.Password))
+	}
+
+}
 
+// Example of using ConnectPacketBuilder to extract server password from URL
+func ExampleClientConfig_ConnectPacketBuilder() {
+	serverURL, _ := url.Parse("mqtt://mqtt_user:[email protected]:1883")
+	config := ClientConfig{
+		ServerUrls:        []*url.URL{serverURL},
+		ConnectRetryDelay: 5 * time.Second,
+		ConnectTimeout:    5 * time.Second,
+		ClientConfig: paho.ClientConfig{
+			ClientID: "test",
+		},
+	}
+	config.ConnectPacketBuilder = func(c *paho.Connect, u *url.URL) *paho.Connect {
+		// Extracting password from URL
+		c.Username = u.User.Username()
+		// up to user to catch empty password passed via URL
+		p, _ := u.User.Password()
+		c.Password = []byte(p)
+		return c
+	}
+	cp := config.buildConnectPacket(false, serverURL)
+	fmt.Printf("user: %s, pass: %s", cp.Username, string(cp.Password))
+	// Output: user: mqtt_user, pass: mqtt_pass
 }

autopaho/net.go

@@ -65,7 +65,7 @@ func establishServerConnection(ctx context.Context, cfg ClientConfig, firstConne
 					cli.SetErrorLogger(cfg.PahoErrors)
 				}
 
-				cp := cfg.buildConnectPacket(firstConnection)
+				cp := cfg.buildConnectPacket(firstConnection, u)
 				connack, err = cli.Connect(connectionCtx, cp) // will return an error if the connection is unsuccessful (checks the reason code)
 				if err == nil {                               // Successfully connected
 					cancelConnCtx()

autopaho/queue/file/queue.go

@@ -156,7 +156,6 @@ func (q *Queue) put(p io.Reader) error {
 	if err != nil {
 		return err
 	}
-
 	if _, err = io.Copy(f, p); err != nil {
 		f.Close()
 		_ = os.Remove(f.Name()) // Attempt to remove the partial file (not much we can do if this fails)