lib/pycriu: changing the default behavior to use the system binary

[herheliuk]

Use system-installed CRIU binary instead of a local file

Thanks to @avagin for suggesting this solution.

Co-authored-by: Andrei Vagin [email protected]
Signed-off-by: Andrii Herheliuk [email protected]

[herheliuk]

Currently, pycriu attempts to use a local CRIU binary, but I believe
it would make more sense to use a system-installed CRIU binary instead.

This approach would provide a more “works out of the box” experience,
as it’s unlikely that the CRIU binary would be located in the current directory.

[avagin]

some tests are failing.

You need to add the local binary directory to PATH in all tests.

[rst0git]

Currently, pycriu attempts to use a local CRIU binary, but I believe it would make more sense to use a system-installed CRIU binary instead.

Note that this behavior is for testing. We want to run tests with a locally built binary, not a system-installed one.

[herheliuk]

@rst0git won't os.execvp resolve to local binary if it is available?

And does tests use criu.py at all?

[herheliuk]

I do not know how to add PATH to tests. Can you guys help with that?

[rst0git]

@herheliuk os.execvp uses the PATH environment variable.

What is the issue you are trying to fix with this change?

[herheliuk]

I'm trying to make it as pleasant 'out of the box' experience as possible.

Since it is unlikely for the binary to be in the same folder in normal circumstances, I recon most users would want to use a system-installed binary anyway, thus we want to make it a default behaviour.

[herheliuk]

Tests might have been failing because I accidentally pushed my fork instead of origin rebase.
I don't think there would be a different criu version installed system-wide on the CI anyway.

You know better, but maybe we don't need to add the binary to PATH in tests.

[avagin]

Currently, pycriu attempts to use a local CRIU binary, but I believe it would make more sense to use a system-installed CRIU binary instead.

Note that this behavior is for testing. We want to run tests with a locally built binary, not a system-installed one.

@rst0git I think this change is doing the right thing. By default, the library has to use the system-installed criu binary.

[rst0git]

LGTM