swam examples unable to start a notebook

[zozo6015]

I am using the swarm examples from the repository when I try to start up a notebook I can see the following errors in the docker-compose console:

hub_1    | [D 2020-03-27 10:15:01.667 JupyterHub dockerspawner:811] Getting container 'jupyter-admin'
hub_1    | [D 2020-03-27 10:15:01.713 JupyterHub swarmspawner:133] Service lrmb1ld status: {'Message': 'preparing',
hub_1    |      'PortStatus': {},
hub_1    |      'State': 'preparing',
hub_1    |      'Timestamp': '2020-03-27T10:13:59.436022091Z'}
hub_1    | [I 2020-03-27 10:15:01.718 JupyterHub dockerspawner:1148] Stopping service jupyter-admin (id: lrmb1ld)
hub_1    | [I 2020-03-27 10:15:01.720 JupyterHub swarmspawner:232] Removing service lrmb1ld82y8sxrbe133vj0td4
hub_1    | [E 2020-03-27 10:15:01.836 JupyterHub gen:974] Exception in Future <Task finished coro=<BaseHandler.spawn_single_user.<locals>.finish_user_spawn() done, defined at /opt/conda/lib/python3.6/site-packages/jupyterhub/handlers/base.py:619> exception=TimeoutError('Timeout',)> after timeout
hub_1    |     Traceback (most recent call last):
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/tornado/gen.py", line 970, in error_callback
hub_1    |         future.result()
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/jupyterhub/handlers/base.py", line 626, in finish_user_spawn
hub_1    |         await spawn_future
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/jupyterhub/user.py", line 486, in spawn
hub_1    |         raise e
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/jupyterhub/user.py", line 406, in spawn
hub_1    |         url = await gen.with_timeout(timedelta(seconds=spawner.start_timeout), f)
hub_1    |     tornado.util.TimeoutError: Timeout
hub_1    |     
hub_1    | [I 2020-03-27 10:15:01.862 JupyterHub log:158] 200 GET /hub/api/users/admin/server/progress (admin@::ffff:62.231.93.77) 50076.50ms
hub_1    | [D 2020-03-27 10:15:06.962 JupyterHub swarmspawner:144] Getting task of service 'jupyter-admin'
hub_1    | [D 2020-03-27 10:15:06.963 JupyterHub dockerspawner:811] Getting container 'jupyter-admin'
hub_1    | [I 2020-03-27 10:15:06.983 JupyterHub dockerspawner:818] Service 'jupyter-admin' is gone
hub_1    | [I 2020-03-27 10:15:06.995 JupyterHub swarmspawner:166] Task for service 'jupyter-admin' is gone
hub_1    | [E 2020-03-27 10:15:06.999 JupyterHub gen:974] Exception in Future <Future finished exception=RuntimeError('Service jupyter-admin not found',)> after timeout
hub_1    |     Traceback (most recent call last):
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/tornado/gen.py", line 970, in error_callback
hub_1    |         future.result()
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/dockerspawner/dockerspawner.py", line 1055, in start
hub_1    |         yield self.start_object()
hub_1    |       File "/opt/conda/lib/python3.6/site-packages/dockerspawner/swarmspawner.py", line 252, in start_object
hub_1    |         raise RuntimeError("Service %s not found" % self.service_name)
hub_1    |     RuntimeError: Service jupyter-admin not found

I was trying to set this up as close as possible to the examples because my custom environment has the same problems and I wanted to see what is different

[songabc]

seems like I have the same problem.
first I set up docker cluster
then I follow the swarm example instroduction, move work dir to sample/swarm/
and run docker-compose build && docker-compose up
when I login with username 'zl', page response with 'Spawn failed: Service jupyter-zl not found' log event.

I also found that on my node machine, singleuserjupyterhub container was try to run with every login request, but finally with exited status.

I think it maybe due to wrong network setting which casuse jupyterhub can't communicate with singleuser container
I am trying to figure it out

[z3ky]

I run into the same problem. Did you find a solution?

[zozo6015]

Yes, I had to create the stack name swarm any other name did not worked. Once the stack name was set as swarm it started to work and it's still working as a charm.

[minrk]

Closing since OP reported a resolution. Other discussion of the issue may be related to #333 where a previous service instance is not fully deleted before creating a new one