We need test(s) for criu-ns script

[Snorch]

We have quiet some reports about criu-ns problems, but we don't have tests to show that when we fix something we don't break everything else.

Links:
criu-ns script - https://github.com/checkpoint-restore/criu/blob/criu-dev/scripts/criu-ns
criu-ns documentation - https://github.com/checkpoint-restore/criu/blob/criu-dev/Documentation/criu-ns.txt

Examples of what the test should check:
#1893 (comment)
#232 (comment)

Notes:

We need to test criu-ns

• with --shell-job and without it
• with --restore-detached and without it

Meaning that you need separate testcases for

• dumpee is init of pidns
• dumpee is not init of pidns
• dumpee to has own session and detached from ttys
• dumpee inherited session from parent and is attached to same tty as parent

We need to have automatic tests integrated in criu CI.

[warusadura]

Hi @Snorch, I'm interested in working on this issue. Can you please tell me a little bit about this issue.

[Snorch]

Hi @Snorch, I'm interested in working on this issue. Can you please tell me a little bit about this issue.

I updated the description.

[warusadura]

Thanks @Snorch! I'll let you know if I have any questions.

[warusadura]

@Snorch I'm still not clear what to do here :)

I think I'll have to create a test case for def wrap_restore(). But, I'm not sure where. Also, I understand that criu usese ZDTM. But, I couldn't find any existing tests for criu-ns

Also, what do you meant by "dumpee"?

[Snorch]

@Snorch I'm still not clear what to do here :)

I think I'll have to create a test case for def wrap_restore().

You can create a test case which runs criu-ns executable, not a function from it.

But, I'm not sure where. Also, I understand that criu usese ZDTM. But, I couldn't find any existing tests for criu-ns

ZDTM is a nice place for a test which checks that criu is able to dump/restore something, in your case you check the additional utility criu-ns, that's why I think the proper place for it would be in test/others/.

Also, what do you meant by "dumpee"?

By dumpee I mean the process which was dumped by criu. For instance, in the first example from header message dumpee was a sleep inf process.

[warusadura]

@Snorch thanks for the reply.

You can create a test case which runs criu-ns executable, not a function from it.

Understood. But, is there an existing test implementation similar to this requirement? Is shell-job a similar implementation?

Also, how do I execute the previously mentioned shell-job test?

[Snorch]

Understood. But, is there an existing test implementation similar to this requirement? Is shell-job a similar implementation?

Yes, I believe you can use shell-job test as a skeleton for your criu-ns test. It is really similar to what we need with criu-ns.

Also, how do I execute the previously mentioned shell-job test?

[ criu]# cd test/others/shell-job
[ shell-job]# python3 run.py

This should do the trick.

[warusadura]

Understood, thank you @Snorch

[warusadura]

@Snorch
When I executed the ./scripts/criu-ns without any arguments, it prints out the usage info. But, when I pass an argument to it as in ./scripts/criu-ns check or ./scripts/criu-ns dump -t 24445, I'm getting the following errors,

['./scripts/criu-ns', 'check']
Traceback (most recent call last):
  File "/..../criu/./scripts/criu-ns", line 268, in <module>
    run_criu(sys.argv[1:])
  File "/..../criu/./scripts/criu-ns", line 83, in run_criu
    os.execlp('criu', *['criu'] + args)
  File "<frozen os>", line 557, in execlp
  File "<frozen os>", line 574, in execvp
  File "<frozen os>", line 616, in _execvpe
  File "<frozen os>", line 607, in _execvpe
FileNotFoundError: [Errno 2] No such file or directory

['./scripts/criu-ns', 'dump', '-t', '24445']
Traceback (most recent call last):
  File "/..../criu/./scripts/criu-ns", line 266, in <module>
    res = wrap_dump()
          ^^^^^^^^^^^
  File "/..../criu/./scripts/criu-ns", line 240, in wrap_dump
    run_criu(sys.argv[1:])
  File "/..../criu/./scripts/criu-ns", line 83, in run_criu
    os.execlp('criu', *['criu'] + args)
  File "<frozen os>", line 557, in execlp
  File "<frozen os>", line 574, in execvp
  File "<frozen os>", line 616, in _execvpe
  File "<frozen os>", line 607, in _execvpe
FileNotFoundError: [Errno 2] No such file or directory

Any idea why?

[warusadura]

cc @rppt

[Snorch]

os.execlp('criu', *['criu'] + args)
FileNotFoundError: [Errno 2] No such file or directory

Error probably says that you don't have criu binary.

[warusadura]

I see. But, I do have the criu binary.

./criu/criu check --unprivileged
Looks good.

[rst0git]

@warusadura os.execlp() is using the PATH environment variable to locate criu.

[warusadura]

Understood. Thanks @rst0git