The integration test is not smart enough to detect used ports

**Describe the bug**
Now in the integration test, the fixture uses fixed network ports. If some ports are used, the integration test will lead to fail, which should be avoided, especially the test sometimes takes very long and the development would become difficult and time-consuming on troubleshooting.

**To Reproduce**
Create any process that may use the port that any fixture will use.

**Expected behavior**
The program should use random ports that available on the operating system.