ssh executing a bash script, python curses, setupterm: could not find terminal

Question

I am developing a python application for a remote system which has a device connected via a serial port.

At the moment my workflow looks like this

• write code locally
• commit to git
• git push
• change to terminal window holding ssh session
• git pull
• run python code

This is kind of awkward and I want to speed things up and increase my work efficiency using some scripts

I have written two scripts, one for local and one for remote

My local script looks like this

#!/bin/bash

# do git commit
if [ "$#" -eq 3 ]
then
    if [ "$1" == "-m" ]
    then
        git commit -am "$2"
    else
        echo "syntax error, -m expected as argument 1"
        exit
    fi
else
    git commit -am "execute.sh script"
fi

# do git push
git push

# login to ssh and execute script
ssh <user>@<ip> 'bash -s' < remote-execute.sh

My remote-execute.sh looks like this

#!/bin/bash

# cd
cd <dir>

# do git pull
git pull

# run python
python3 main.py

My python code uses Python Curses (ncurses) for GUI interaction

When I run these scripts, I encounter the error

Traceback (most recent call last):
  File "Monitor.py", line 1140, in <module>
    curses.wrapper(main)
  File "/usr/lib/python3.5/curses/__init__.py", line 73, in wrapper
    stdscr = initscr()
  File "/usr/lib/python3.5/curses/__init__.py", line 30, in initscr
    fd=_sys.__stdout__.fileno())
_curses.error: setupterm: could not find terminal

This must be due to how I am using ssh with the "-s" switch to execute the remote script.

Is there a way to fix this? It seems like some kind of terminal stuff isn't being forwarded properly? I can't say anything more than this because it's a bit beyond my knowledge.

Answer 1

The ssh client does not allocate a terminal when being run in "batch" mode (with a command provided). You need to use the -t option to enable this if you're asking it to run an interactive app.

Additionally, redirecting stdin doesn't make sense when trying to run an interactive program – although you could force tty allocation (using -tt), your program would just try reading input from the .sh file instead of keyboard.

ssh -t <user>@<ip> "cd <dir> && git pull --ff-only && python3 main.py"

ssh -t <user>@<ip> "$(cat remote-commands.txt)"