Add process test

[sat0ken]

This implements the process validation in #361.

[sat0ken]

@utam0k @YJDoc2

I figure out why the test failed.

I reproduced it on my PC.
If /test does not exist in the rootfs, the youki execution will fail same as the E2E tests.

root@satoken:~/work/rootfs# ls
bin  boot  config.json  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@satoken:~/work/rootfs# youki run test
ERROR libcontainer::process::container_init_process: failed to chdir e=ENOENT
ERROR libcontainer::process::container_intermediate_process: failed to initialize container process: failed to unix syscall
ERROR libcontainer::process::container_main_process: failed to wait for init ready: exec process failed with error error in executing process : failed to unix syscall
ERROR libcontainer::container::builder_impl: failed to run container process exec process failed with error error in executing process : failed to unix syscall
ERROR youki: error in executing command: exec process failed with error error in executing process : failed to unix syscall
run failed : exec process failed with error error in executing process : failed to unix syscall

But runc is, even if /test is not in rootfs, runc run is working.

root@satoken:~/work/rootfs# ls
bin  boot  config.json  dev  etc  home  lib  lib64  media  mnt  opt  proc  root  run  sbin  srv  sys  tmp  usr  var
root@satoken:~/work/rootfs# runc run test
/test

If we add a test directory to the rootfs you use for testing, the tests will pass.
However, to resolve the error, maybe I need to check youki's code that prepares the rootfs?

Sorry, I don't understand the detailed code of runc or youki, but I think it looks like runc is creating the cwd directory in this line.

What is the difference between the behavior of runc and youki?

[sat0ken]

@utam0k @YJDoc2 ping!
Please confirm.

#2968 (comment)

[YJDoc2]

Hey, thanks for the ping, I'll try to take a look at this today.

[YJDoc2]

Some comments, also there are several warnings from the CI check, please take a look

[YJDoc2]

Hey @sat0ken , I took a look at the code and there are two things -

1. In the test (as per my comment), you are not creating the /test dir correctly. Hence youki does not find it and fails.
2. As for if to to follow or not runc's way of creating the cwd if not present, I think we should check and stick to the runtime spec, I'll check and get back to you. But if the failing test is fixed by correctly creating the dir, then maybe we should not copy this.

[YJDoc2]

Also @sat0ken a small request, please ping/comment in the tracking issue before opening a e2e test PR, so we can properly keep track. I have added your current PRs, but please comment for future ones. Thanks!

[sat0ken]

@YJDoc2
Thank you for your comments and confirmation. I will fix the code.
I am newbie to contribution, so I apologize for not following the rules. Thank you for your continued support!

[YJDoc2]

Hey @sat0ken , There are some conflicts and I have left a comment above on the still failing tests, please take a look.

[sat0ken]

@YJDoc2 Hi, thank you for comment and support. I fixed conflict and code. Could you please check?

[sat0ken]

@YJDoc2 Ping!

[YJDoc2]

some nitpicks, but overall looks good.

[sat0ken]

@YJDoc2 Thank you for review and comments. I've fixed the code. Could you please check the code?

[YJDoc2]

lgtm 👍 Thanks