KernelRestarter: restart failed in Jupyter

2017-02-03 17-43-26 by Kamushin

If run jupyter notebook as Docker entrypoint, then jupyter will be the root process with pid 1.
For some reason, this doesn't play well with IPython, and the Kernel won't be started successfully.
Errors may occur like below:

[I 08:49:49.637 NotebookApp] KernelRestarter: restarting kernel (1/5)
[D 08:49:49.638 NotebookApp] Starting kernel: ['/usr/bin/python', '-m', 'ipykernel', '-f', u'/root/.local/share/jupyter/runtime/kernel-5a23f4ca-734b-422f-9c1c-e0ad126f6552.json']
[D 08:49:49.643 NotebookApp] Connecting to: tcp://127.0.0.1:54341
[I 08:49:52.646 NotebookApp] KernelRestarter: restarting kernel (2/5)
[D 08:49:52.647 NotebookApp] Starting kernel: ['/usr/bin/python', '-m', 'ipykernel', '-f', u'/root/.local/share/jupyter/runtime/kernel-5a23f4ca-734b-422f-9c1c-e0ad126f6552.json']
[D 08:49:52.652 NotebookApp] Connecting to: tcp://127.0.0.1:54341
[I 08:49:55.655 NotebookApp] KernelRestarter: restarting kernel (3/5)
[D 08:49:55.656 NotebookApp] Starting kernel: ['/usr/bin/python', '-m', 'ipykernel', '-f', u'/root/.local/share/jupyter/runtime/kernel-5a23f4ca-734b-422f-9c1c-e0ad126f6552.json']
[D 08:49:55.662 NotebookApp] Connecting to: tcp://127.0.0.1:54341
[W 08:49:56.713 NotebookApp] Timeout waiting for kernel_info reply from 5a23f4ca-734b-422f-9c1c-e0ad126f6552
[D 08:49:56.715 NotebookApp] Opening websocket /api/kernels/5a23f4ca-734b-422f-9c1c-e0ad126f6552/channels
[D 08:49:56.715 NotebookApp] Connecting to: tcp://127.0.0.1:42528
[D 08:49:56.715 NotebookApp] Connecting to: tcp://127.0.0.1:58272
[D 08:49:56.716 NotebookApp] Connecting to: tcp://127.0.0.1:52503
[I 08:49:58.664 NotebookApp] KernelRestarter: restarting kernel (4/5)
WARNING:root:kernel 5a23f4ca-734b-422f-9c1c-e0ad126f6552 restarted
[D 08:49:58.665 NotebookApp] Starting kernel: ['/usr/bin/python', '-m', 'ipykernel', '-f', u'/root/.local/share/jupyter/runtime/kernel-5a23f4ca-734b-422f-9c1c-e0ad126f6552.json']
[D 08:49:58.670 NotebookApp] Connecting to: tcp://127.0.0.1:54341
[W 08:50:01.672 NotebookApp] KernelRestarter: restart failed

Then I try to use sh -c 'jupyter notebook' as the entrypoint, it maybe works for someone else, but for my specfic docker version, jupyter still run as root process.
The final solution is using a start.sh to wrapp sh -c 'jupyter notebook'. That works for me.