Using Jupyter Lab with tmpnb - proxy

Question

I am trying to use JupyterLab using tmpnb
I want to spawn many JupyterLab instances, just like the way tmpnb does for Jupyter Notebook.
I have created a new docker image by docker build -t jupyterlab2 . command using the following Dockerfile:
FROM jupyter/datascience-notebook
MAINTAINER apr
RUN pip install npm
RUN pip install jupyterlab
RUN jupyter serverextension enable --py jupyterlab
After this I am running the following commands:
export TOKEN=$( head -c 30 /dev/urandom | xxd -p )
docker run --net=host -d -e CONFIGPROXY_AUTH_TOKEN=$TOKEN --name=proxy jupyter/configurable-http-proxy --default-target http://127.0.0.1:9999
docker run --net=host -d -e CONFIGPROXY_AUTH_TOKEN=$TOKEN --name=tmpnb -v /var/run/docker.sock:/docker.sock jupyter/tmpnb python orchestrate.py --allow_origin='*' --image='jupyterlab2' --pool-size=5 --container-user=root --command='jupyter lab --allow-root LabApp.allow_origin="*"'
When I visit the URL http://<ip-address>:8000, I get redirected to http://<ip>:8000/user/sTVKGwH01uoQ, but this shows 404.
I also tried visiting http://<ip>:8000/user/sTVKGwH01uoQ/lab but this too gives 404.
Logs for 1 instance are below:
Set username to: jovyan
usermod: no changes
Set jovyan GID to: 100
Execute the command: jupyter lab --allow-root --port 8888 --ip=0.0.0.0 --LabApp.allow_origin=*
[I 09:05:52.598 LabApp] Writing notebook server cookie secret to /home/jovyan/.local/share/jupyter/runtime/notebook_cookie_secret
[I 09:05:54.689 LabApp] JupyterLab alpha preview extension loaded from /opt/conda/lib/python3.6/site-packages/jupyterlab
[I 09:05:54.694 LabApp] Serving notebooks from local directory: /home/jovyan
[I 09:05:54.694 LabApp] 0 active kernels
[I 09:05:54.694 LabApp] The Jupyter Notebook is running at:
[I 09:05:54.694 LabApp] http://0.0.0.0:8888/?token=584fc5114d037ad23296ca8284ea1074b220d058018cb2c4
[I 09:05:54.694 LabApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[C 09:05:54.695 LabApp]
Copy/paste this URL into your browser when you connect for the first time,
to login with a token:
http://0.0.0.0:8888/?token=584fc5114d037ad23296ca8284ea1074b220d058018cb2c4
[I 09:05:57.142 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 0.54ms
[W 09:05:57.144 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 1.45ms referer=None
[I 09:05:57.347 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 0.56ms
[W 09:05:57.350 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 1.44ms referer=None
[I 09:05:57.553 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 0.55ms
[W 09:05:57.556 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 1.41ms referer=None
[I 09:05:57.767 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 2.80ms
[W 09:05:57.773 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 3.44ms referer=None
[I 09:05:57.978 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 0.56ms
[W 09:05:57.981 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 1.46ms referer=None
[I 09:05:58.184 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 0.55ms
[W 09:05:58.187 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 1.42ms referer=None
[I 09:05:58.391 LabApp] 302 GET /user/1BhE9UZ2gg5o/ (172.17.0.1) 0.56ms
[W 09:05:58.394 LabApp] 404 GET /user/1BhE9UZ2gg5o (172.17.0.1) 2.05ms referer=None
[W 09:06:18.518 LabApp] 404 GET /user/1BhE9UZ2gg5o/tree (172.17.0.1) 1.61ms referer=http://52.71.15.52:8000/
[W 09:06:27.502 LabApp] 404 GET /user/1BhE9UZ2gg5o/lab (172.17.0.1) 2.51ms referer=None
[W 09:07:20.568 LabApp] 404 GET /user/1BhE9UZ2gg5o/lab (172.17.0.1) 2.28ms referer=None
I looked at an issue related to JupyterHub, which looked very similar. The 404 error page is same for me too. I tried some random things with start.sh too, but no luck.
Is it even possible to run JupyterLab using tmpnb? If no, then what are the other tools that I can use the achieve the same purpose?

Answer 1

The base URL must be set, otherwise the /user/... routes won't map to the right things. This is the --NotebookApp.base_url={base_path} part in the all of the example commands in the tmpnb README. These look like:
python orchestrate.py --command='jupyter notebook --no-browser \
--port {port} --ip=0.0.0.0 --NotebookApp.base_url={base_path} \
--NotebookApp.port_retries=0'
So a JupyterLab equivalent would be:
python orchestrate.py --command='jupyter lab --no-browser \
--port {port} --ip=0.0.0.0 --NotebookApp.base_url={base_path} \
--NotebookApp.port_retries=0'
All of those apply with jupyterlab as well, so probably the only arg you want to replace is notebook with lab. At the same time, you don't need to change the default command at all, because if the lab extension is installed, jupyterlab is available at the /lab URL when you start jupyter notebook. You can see this right now by replacing /tree with /lab on any existing tmpnb.org URL.