OCPBUGS-18995: Move chroot from multus main process to its child processes (#1161)

[pliurh]

We used to run chroot in multus main process when calling other CNI plugin binary. We also use a mutex to lock the access to pod files. But this causes performance issues when facing heavy CNI_ADD/CNI_DEL requests.

With this patch, we do chroot in the child processes instead. So file operations in the main process will not be affected by chroot.

This change requires the multus thick plugin pod to mount CNI bin directory to the same path in the container host.

[openshift-ci-robot]

@pliurh: This pull request references Jira Issue OCPBUGS-18995, which is invalid:

• expected the bug to target the "4.15.0" version, but no target version was set

Comment /jira refresh to re-evaluate validity if changes to the Jira bug are made, or edit the title of this pull request to link to a different bug.

The bug has been updated to refer to the pull request using the external bug tracker.

In response to this:

We used to run chroot in multus main process when calling other CNI plugin binary. We also use a mutex to lock the access to pod files. But this causes performance issues when facing heavy CNI_ADD/CNI_DEL requests.

With this patch, we do chroot in the child processes instead. So file operations in the main process will not be affected by chroot.

This change requires the multus thick plugin pod to mount CNI bin directory to the same path in the container host.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[pliurh]

/jira refresh

[openshift-ci-robot]

@pliurh: This pull request references Jira Issue OCPBUGS-18995, which is valid. The bug has been moved to the POST state.

3 validation(s) were run on this bug

• bug is open, matching expected state (open)
• bug target version (4.15.0) matches configured target version for branch (4.15.0)
• bug is in the state ASSIGNED, which is one of the valid states (NEW, ASSIGNED, POST)

No GitHub users were found matching the public email listed for the QA contact in Jira (weliang@redhat.com), skipping review request.

In response to this:

/jira refresh

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[s1061123]

/lgtm

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pliurh, s1061123

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[openshift-ci-robot]

/retest-required

Remaining retests: 0 against base HEAD 74da9fc and 2 for PR HEAD 5447518 in total

[pliurh]

/retest

[s1061123]

/retest-required

[openshift-ci]

@pliurh: all tests passed!

Full PR test history. Your PR dashboard.

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[openshift-ci-robot]

@pliurh: Jira Issue OCPBUGS-18995: All pull requests linked via external trackers have merged:

• openshift/multus-cni#186

Jira Issue OCPBUGS-18995 has been moved to the MODIFIED state.

In response to this:

We used to run chroot in multus main process when calling other CNI plugin binary. We also use a mutex to lock the access to pod files. But this causes performance issues when facing heavy CNI_ADD/CNI_DEL requests.

With this patch, we do chroot in the child processes instead. So file operations in the main process will not be affected by chroot.

This change requires the multus thick plugin pod to mount CNI bin directory to the same path in the container host.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[openshift-merge-robot]

Fix included in accepted release 4.15.0-0.nightly-2023-09-27-073353