loadgenerator failed to start when ipv6 is disabled

[MoZhonghua]

Bug Report

Which version of the demo you are using? (please provide either a specific
1.8.0

Symptom

loadgenerator failed to start when ipv6 is disabled, with this error:

[2024-03-07 07:16:25,064] 66b18b2f58e5/INFO/locust.main: Starting web interface at http://0.0.0.0:8089 (accepting connections from all network interfaces)
[2024-03-07 07:16:25,074] 66b18b2f58e5/INFO/locust.main: Starting Locust 2.18.2
[2024-03-07 07:16:25,074] 66b18b2f58e5/INFO/locust.main: No run time limit set, use CTRL+C to interrupt
Traceback (most recent call last):
  File "src/gevent/greenlet.py", line 908, in gevent._gevent_cgreenlet.Greenlet.run
  File "/usr/local/lib/python3.12/site-packages/locust/web.py", line 512, in start_server
    self.server.serve_forever()
  File "/usr/local/lib/python3.12/site-packages/gevent/baseserver.py", line 398, in serve_forever
    self.start()
  File "/usr/local/lib/python3.12/site-packages/gevent/baseserver.py", line 336, in start
    self.init_socket()
  File "/usr/local/lib/python3.12/site-packages/gevent/pywsgi.py", line 1668, in init_socket
    StreamServer.init_socket(self)
  File "/usr/local/lib/python3.12/site-packages/gevent/server.py", line 173, in init_socket
    self.socket = self.get_listener(self.address, self.backlog, self.family)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/gevent/server.py", line 185, in get_listener
    return _tcp_listener(address, backlog=backlog, reuse_addr=cls.reuse_addr, family=family)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/gevent/server.py", line 260, in _tcp_listener
    sock = GeventSocket(family=family)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/gevent/_socket3.py", line 125, in __init__
    self._sock = self._gevent_sock_class(family, type, proto, fileno)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: [Errno 97] Address family not supported by protocol

What is the expected behavior?

Shoud startup successfully.

What is the actual behavior?

Failed to start.

Reproduce

sudo vim /etc/sysctl.conf
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
reboot

docker run --rm -it --entrypoint bash ghcr.io/open-telemetry/demo:1.8.0-loadgenerator
locust   # failed to start
locust --web-host 0.0.0.0   # start ok

Additional Context

see this: locustio/locust#556

[puckpuck]

@MoZhonghua can you add - LOCUST_WEB_HOST=0.0.0.0 to the environment variables list for the loadgenerator in docker-compose.yml?

[MoZhonghua]

@MoZhonghua can you add - LOCUST_WEB_HOST=0.0.0.0 to the environment variables list for the loadgenerator in docker-compose.yml?

- LOCUST_WEB_HOST=0.0.0.0 works.

Should I create a PR to fix this? I'll add this env to docker-compose.minimal.yml and docker-compose.yml.

[puckpuck]

@MoZhonghua can you add - LOCUST_WEB_HOST=0.0.0.0 to the environment variables list for the loadgenerator in docker-compose.yml?

- LOCUST_WEB_HOST=0.0.0.0 works.

Should I create a PR to fix this? I'll add this env to docker-compose.minimal.yml and docker-compose.yml.

Yes. I think adding the environment variable to the proper section in .env, then referencing it in both docker compose files is what we need.