Proper fix to server being spontaneously deleted on restart (#128)

Closes #104

Thanks @sjdemartini for catching this fix in
https://jupyterhub.readthedocs.io/en/stable/changelog.html#bugs-fixed.

roles/jupyterhub/defaults/main.yml

@@ -9,7 +9,7 @@ jupyterhub_proxy_auth_token: "m8dfdKvyVJ0bWTNpbVCQyoCt"
 cdsdashboards_enabled: true
 
 jupyterhub_enabled: false
-jupyterhub_version: ">=1.3.0"
+jupyterhub_version: ">=2.3.0"
 jupyterhub_port: "15001"
 jupyterhub_base_url: "/"
 jupyterhub_hub_environment: "environments/jupyterhub.yaml"

roles/jupyterhub/templates/jupyterhub_config.py

@@ -119,14 +119,6 @@ async def authenticate(self, handler, data):
 # -------------------- Base Spawner --------------------
 
 class QHubHPCSpawnerBase(SlurmSpawner):
-  async def poll(self):
-      # on server restart the IP and port appears to change when poll() is called
-      # on the server object. This shim ensures that those are preserved
-      ip, port = self.server.ip, self.server.port
-      value = await super().poll()
-      self.server.ip, self.server.port = ip, port
-      return value
-
   req_conda_environment_prefix = Unicode('',
         help="Conda environment prefix to launch jupyterlab"
     ).tag(config=True)