Mask dmesg_restric as part of procSysKernel handler

[felipecrs]

• As suggested by @rodnymolina at write sysctl key kernel.domainname: open /proc/sys/kernel/domainname: permission denied: unknown sysbox#287 (comment)
• Closes Support writing to /proc/sys/kernel/dmesg_restrict inside system containers sysbox#599

[felipecrs]

@rodnymolina this indeed fix the issue. Can be tested with:

$ docker run --rm --runtime sysbox-runc ubuntu sysctl kernel.dmesg_restrict=0
kernel.dmesg_restrict = 0

Without these changes, it fails with:

$ docker run --rm --runtime sysbox-runc ubuntu sysctl kernel.dmesg_restrict=0
sysctl: permission denied on key "kernel.dmesg_restrict", ignoring

[rodnymolina]

@felipecrs, your changes look good but there are a couple of issues that need to be addressed before you merge this PR:

1. The sysbox branch that you have used for this PR is not based off of our latest master branch, so a few of our integration testcases are failing. Unfortunately, we are having some issues with our CI right now, so I cloned your branch and manually ran the tests, which confirmed what I just mentioned:

$ git log --oneline -10 mask-dmesg_restrict
74f0254 (felipe-fork/mask-dmesg_restrict, felipe-pr-77) Mask dmesg_restric
95a773a Lower log level of error message from err -> warn.
2234afb Lower sysbox-fs log message from error to debug.
c1ed450 Address review comments for previous commits

$ git show 95a773a | egrep Date
Date:   Sat Mar 19 20:43:56 2022 +0000

2. There are a few minor changes required on top of your current commit. I took care of those and submit a new commit on top of your personal mask-dmesg_restrict branch, please add this one to your PR update.

$ git log --oneline -10
71b225f (HEAD -> mask-dmesg_restrict, felipe-fork/mask-dmesg_restrict) Adjust 'dmesg_restrict' supported range as part of procSysKernel handler
74f0254 (felipe-pr-77) Mask dmesg_restrict

[felipecrs]

Hi @rodnymolina, sorry about that. I was applying the patch on top of v0.5.2, and that's why it was outdated. I totally forgot to update it while creating the PR.

Thanks for finishing it as well. I also squashed your commit into mine to keep the history clean.

[rodnymolina]

Thanks @felipecrs -- I just verified that things are looking good now.

[rodnymolina]

LG