Update default Debezium Server HTTP port to use random freeport inste…

…ad of 8080 (#1691)

- Fetching free port dynamically by connecting to Port 0. Generally it returns 5 digit port numbers so there shouldn't be conflicts with standard ports like 5432, 8080 etc

yb-voyager/src/dbzm/config.go

@@ -81,6 +81,7 @@ type Config struct {
 var baseConfigTemplate = `
 debezium.format.value=connect
 debezium.format.key=connect
+quarkus.http.port=%d
 quarkus.log.console.json=false
 quarkus.log.level=%s
 `
@@ -295,10 +296,19 @@ func (c *Config) String() string {
 	} else {
 		log.Infof("QUEUE_SEGMENT_MAX_BYTES: %d", queueSegmentMaxBytes)
 	}
+
+	quarkusLogPort, err := utils.GetFreePort()
+	if err != nil {
+		log.Warnf("failed to get a free port for quarkus http server, falling back to 8080: %v", err)
+		quarkusLogPort = 8080
+	}
+	log.Infof("using port number %d for quarkus http server", quarkusLogPort)
+
 	var conf string
 	switch c.SourceDBType {
 	case "postgresql":
 		conf = fmt.Sprintf(postgresConfigTemplate,
+			quarkusLogPort,
 			c.LogLevel,
 			c.Username,
 			c.SnapshotMode,
@@ -332,6 +342,7 @@ func (c *Config) String() string {
 	case "yugabytedb":
 		if !c.UseYBgRPCConnector {
 			conf = fmt.Sprintf(yugabyteLogicalReplicationConfigTemplate,
+				quarkusLogPort,
 				c.LogLevel,
 				c.Username,
 				"never",
@@ -359,6 +370,7 @@ func (c *Config) String() string {
 			}
 		} else {
 			conf = fmt.Sprintf(yugabyteConfigTemplate,
+				quarkusLogPort,
 				c.LogLevel,
 				c.Username,
 				"never",
@@ -391,6 +403,7 @@ func (c *Config) String() string {
 		}
 	case "oracle":
 		conf = fmt.Sprintf(oracleConfigTemplate,
+			quarkusLogPort,
 			c.LogLevel,
 			c.Username,
 			c.SnapshotMode,
@@ -422,6 +435,7 @@ func (c *Config) String() string {
 
 	case "mysql":
 		conf = fmt.Sprintf(mysqlConfigTemplate,
+			quarkusLogPort,
 			c.LogLevel,
 			c.Username,
 			c.SnapshotMode,

yb-voyager/src/utils/utils.go

@@ -684,3 +684,17 @@ func ChangeFileExtension(filePath string, newExt string) string {
 
 	return filePath + newExt
 }
+
+// Port 0 generally returns port number in range 30xxx - 60xxx but it also depends on OS and network configuration
+func GetFreePort() (int, error) {
+	// Listen on port 0, which tells the OS to assign an available port
+	listener, err := net.Listen("tcp", ":0")
+	if err != nil {
+		return 0, fmt.Errorf("failed to listen on a port: %v", err)
+	}
+	defer listener.Close()
+
+	// Retrieve the assigned port
+	addr := listener.Addr().(*net.TCPAddr)
+	return addr.Port, nil
+}