Terminal does not understand tab/arrow keys inside docker

[yebrahim]

I run Jupyter inside docker. When I open a terminal window in Jupyter in this case, pressing Tab sends the cursor to the next tab stop immediately instead of performing autocomplete. Also arrow keys just print values like ^[[A instead of actually moving cursor, or showing command history.

I'm not sure if this is a Jupyter or xterm.js issue, does anyone know what's causing this? It only happens inside docker (tried both ubuntu and debian images).

[takluyver]

The symptoms you describe sound like it's running a plain sh instead of bash. sh is the default shell if the $SHELL environment does not point to something else.

[yebrahim]

$SHELL is set to /bin/bash in the container though.

[takluyver]

I'm not sure, then. Certainly those symptoms sound like a shell that's not using readline.

[yebrahim]

You're right actually. Even though doing echo $SHELL inside the container gives me /bin/bash, doing it inside the Jupyter terminal shows it's unassigned, thus the dumb behavior.

Can Jupyter execute export SHELL=/bin/bash for new terminals?

[takluyver]

Jupyter is using the SHELL environment variable to pick the shell to start, so you'd need to set that before starting Jupyter. Alternatively, the NotebookApp.terminado_settings config option can override it.

[yebrahim]

Thanks for the pointer, I fixed the issue by explicitly setting the SHELL env var to /bin/bash as part of the Dockerfile.
Closing this one.

[Febin-kg]

@yebrahim - Could you please tell me how you did it ?
I've set the shell ENV variable in my Dockerfile to point to /bin/bash.
However, when i docker exec -it container_id sh, it still is sh which is being loaded. The tab isn't
being recognised.
echo $SHELL does give me the output as /bin/bash.
I can alternately perform docker exec -it container_id /bin/bash, but I'm trying to default the shell to /bin/bash

[yebrahim]

Have your tried using the SHELL command?

[changec]

I use the tensorflow/tensorflow image to open the jupyter,but the default terminal was sh.
can you tell me how to rewrite the dockerfile?
I want to open the bash terminal,thank you.

I change my Dockerfile and rebuild the image
RUN ["rm","/bin/sh"]
RUN ["ln", "-s", "/bin/bash", "/bin/sh"]
although the jupyter notebook still run sh,but it can use tab keys.
sh-4.3# ls
1_hello_tensorflow.ipynb 2_getting_started.ipynb 3_mnist_from_scratch.ipynb BUILD LICENSE
sh-4.3# cat 1_hello_tensorflow.ipynb

[nithincninan]

Added environmental path

• SHELL=/bin/bash

in windows and the issue is resolved.