Spawned container network settings not populated

[vincenzon]

My spawned containers are not getting their network settings populated. When I inspect the spawned container's network settings I see:

        "Networks": {
            "jupyterhub_network": {
                "IPAMConfig": null,
                "Links": null,
                "Aliases": [
                    "f53d628d5d68"
                ],
                "NetworkID": "8216769bc20a2aec29fd8de162031ccd584f9f3ee391855942b2a1e2a7113159",
                "EndpointID": "",
                "Gateway": "",
                "IPAddress": "",
                "IPPrefixLen": 0,
                "IPv6Gateway": "",
                "GlobalIPv6Address": "",
                "GlobalIPv6PrefixLen": 0,
                "MacAddress": "",
                "DriverOpts": null
            }

This leads to a failure to start the container:

Error starting server matt: The 'ip' trait of a Server instance expected a unicode string, not the NoneType None.

Expected behaviour

I think the IPAddress field should show the ip address on the jupyterhub_network, as for example it does for the hub container:

        "Networks": {
            "jupyterhub_network": {
                "IPAMConfig": null,
                "Links": null,
                "Aliases": [
                    "a6292862e2c7",
                    "jupyterhub"
                ],
                "NetworkID": "8216769bc20a2aec29fd8de162031ccd584f9f3ee391855942b2a1e2a7113159",
                "EndpointID": "7559ad58e2b871ad3ba7b0c53a6ccfd9a8bf8ef54bc6101bd46044532aa417d2",
                "Gateway": "172.26.0.1",
                "IPAddress": "172.26.0.2",
                "IPPrefixLen": 16,
                "IPv6Gateway": "",
                "GlobalIPv6Address": "",
                "GlobalIPv6PrefixLen": 0,
                "MacAddress": "02:42:ac:1a:00:02",
                "DriverOpts": null
            }

Actual behaviour

If I start the spawn container from the command line, I do see network settings populated:

docker run -it --network jupyterhub_network jupyterlab_img bash

Yields:

        "Networks": {
            "jupyterhub_network": {
                "IPAMConfig": null,
                "Links": null,
                "Aliases": [
                    "b00e6fe8fa9c"
                ],
                "NetworkID": "8216769bc20a2aec29fd8de162031ccd584f9f3ee391855942b2a1e2a7113159",
                "EndpointID": "f332478214ae493761fa2b70f051cc08a6204f1db18ebd927754132266a1dd74",
                "Gateway": "172.26.0.1",
                "IPAddress": "172.26.0.3",
                "IPPrefixLen": 16,
                "IPv6Gateway": "",
                "GlobalIPv6Address": "",
                "GlobalIPv6PrefixLen": 0,
                "MacAddress": "02:42:ac:1a:00:03",
                "DriverOpts": null
            }
        }

My setup is following the jupyterhub-deploy-docker repo. I think the relevant settings are:

docker-compose.yml, each service is tagged with the network and it is named at the end:

    ...
    networks:
      - jupterhub_network

networks:
  jupterhub_network:
    external:
      name: jupyterhub_network

The network exists and the sha matches the values in the inspect's above:

$ docker network ls | grep jup
8216769bc20a   jupyterhub_network     bridge    local

The jupyterhub config points to:

## Docker spawner
c.JupyterHub.spawner_class = 'dockerspawner.DockerSpawner'
c.DockerSpawner.image = 'jupyterlab_img'
c.DockerSpawner.network_name = 'jupyterhub_network'
# See https://github.com/jupyterhub/dockerspawner/blob/master/examples/oauth/jupyterhub_config.py
c.JupyterHub.hub_ip = 'jupyterhub'
c.JupyterHub.hub_port = 8080

Thanks for any help that you can provide.