use hostname if register name not set (#3968)

deployer/src/main/java/com/alibaba/otter/canal/deployer/CanalLauncher.java

@@ -56,6 +56,10 @@ public class CanalLauncher {
                     CanalConstants.CANAL_ADMIN_AUTO_REGISTER));
                 String autoCluster = CanalController.getProperty(properties, CanalConstants.CANAL_ADMIN_AUTO_CLUSTER);
                 String name = CanalController.getProperty(properties, CanalConstants.CANAL_ADMIN_REGISTER_NAME);
+                if (StringUtils.isEmpty(name)) {
+                    name = AddressUtils.getHostName();
+                }
+
                 String registerIp = CanalController.getProperty(properties, CanalConstants.CANAL_REGISTER_IP);
                 if (StringUtils.isEmpty(registerIp)) {
                     registerIp = AddressUtils.getHostIp();