errors not handled correctly in function [ spython/main/run.py. ] run()

[al3x609]

Expected Behavior

the function run should not get to execute this error AttributeError: 'NoneType' object has no attribute 'strip' in case of previous errors

like to:
ERROR Return Code -15: ( ... message ...)

Actual Behavior

this a intencional test:
I deploy a container that ends all processes within it after a defined time, with a call to kill

the first error ERROR Return Code -15 is correct because subprocess.Popen.returncode return -15 with the Unix signal SIGTERM=-15, sent by a call to kill;

but I should not get to evaluate the sentence result = result.strip('\n')

due to the error caught in the previous step

Steps to Reproduce

• start any container indefinitely
• kill the principal process inside de container in another terminal.
• check the output in the first shell
  route access
  spyton.main.run.__init.__py._run_command -> Client._run_command -> command.run_command -> run_cmd(utils.terminal.run_command ) => subprocess.communicate()

Context

• Operating System: centos 7 64 bits
• singularity version: latest
• spython version: latest
• python version: 3.7

Failure Logs

Possible Fix

before

    result = result.strip('\n')

after

    if(result):
        result = result.strip('\n')

[vsoch]

Agreed! Can you give me a dummy case to test this (and check the fix is sufficient?)

[al3x609]

yes,

Bootstrap: docker

From: nginx

%runscript
exec   nginx

I made another test and find the real fail:
---- Popen.communicate() returns a tuple (stdoutdata, stderrdata)----> lines(,).

terminal.py -> run_command() return a dict output={.'message': lines, 'return_code': process.returncode }

ìf ('return_code' == 0) -> command.py -> run_command() return  the 'message'  -> lines -> a tuple

• Now in run.py -> line 94 result = result.strip('\n') fail because the tuples no has attribute .strip()

for example if stdout=" " , lines value show ('2.6.0-HEAD.579c415\n',)

• previously what I did was to avoid the problem, not correct it :(

I'm not sure if we should suppress the error, because I have not read all the code where it can affect the most.

[vsoch]

hey @al3x609 my instinct is to be more conservative here - the run that we are looking at is starting a service, and logically it's not going to return a result in the same way as executing a container (like running a script to get a result). Since the general functions to run commands need to be just that, it seems correct that None is returned to them, and the bug is higher up assuming that it's not a service and trying to return a result. So instead of editing those functions, I've done your suggested fix to check for the result, and opened a PR here --> #63 if you would care to review! Thank you!