OCPBUGS-17787: Fix sysctl breaking dots in paths

[mkowalski]

Using sysctl to modify paths containing dots is known to cause issues due to the fact that sysctl blindly assumes that dot is always a separator and is changed to /.

This is a problem when we want to configure a network interface containing a dot in its name, e.g. bond0.354, because net.ipv4.conf.bond0.354.forwarding=1 expands to
/proc/sys/net/ipv4/conf/bond0/354/forwarding when in reality it should be /proc/sys/net/ipv4/conf/bond0.354/forwarding.

To remediate this we are changing the call from
sysctl -w net.ipv4.conf.bond0.354.forwarding=1 to echo "1" > /proc/sys/net/ipv4/conf/bond0.354/forwarding as there is no simple way to change the behaviour of sysctl.

In the current form the call is breaking the script as writing a value to a non-existing path returns an error cannot stat [...] No such file or directory

Fixes: OCPBUGS-17787

[openshift-ci-robot]

@mkowalski: This pull request references Jira Issue OCPBUGS-17787, which is invalid:

• expected the bug to target the "4.14.0" 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:

Using sysctl to modify paths containing dots is known to cause issues due to the fact that sysctl blindly assumes that dot is always a separator and is changed to /.

This is a problem when we want to configure a network interface containing a dot in its name, e.g. bond0.354, because net.ipv4.conf.bond0.354.forwarding=1 expands to
/proc/sys/net/ipv4/conf/bond0/354/forwarding when in reality it should be /proc/sys/net/ipv4/conf/bond0.354/forwarding.

To remediate this we are changing the call from
sysctl -w net.ipv4.conf.bond0.354.forwarding=1 to echo "1" > /proc/sys/net/ipv4/conf/bond0.354/forwarding as there is no simple way to change the behaviour of sysctl.

In the current form the call is breaking the script as writing a value to a non-existing path returns an error cannot stat [...] No such file or directory

Fixes: OCPBUGS-17787

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.

[mkowalski]

/cc @trozet
as author of the original code

/cc @cybertron
as on-prem networking

/cc @sinnykumari
as MCO owner

[openshift-ci]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[mkowalski]

/jira refresh

[openshift-ci-robot]

@mkowalski: This pull request references Jira Issue OCPBUGS-17787, which is invalid:

• expected the bug to target the "4.14.0" version, but it targets "4.14" instead

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.

In response to this:

/jira refresh

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.

[rbbratta]

please quote "${iface}"

Can interfaces ever contain a / ?

[mkowalski]

Done.

TLDR: / and white characters are forbidden from interface names

Longer version: Validations for iproute2 are defined in this code -- https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/lib/utils.c?id=1f420318bda3cc62156e89e1b56d60cc744b48ad#n827. Different tools may allow and disallow different variations, but let's also be clear that we cannot support every single tool out there and cover for every corner case. We can fix them as they arrive though

[rbbratta]

" should handle shell meta-characters or globbing. We could always fuzz.

[cybertron]

/test e2e-metal-ipi-ovn-ipv6

The OpenStack job should cover the ipv4 case and the metal job will make sure ipv6 still works.

/lgtm

Assuming the ci jobs pass.

[mkowalski]

/test e2e-openstack

level=info msg=Obtaining RHCOS image file from 'https://rhcos.mirror.openshift.com/art/storage/prod/streams/4.14-9.2/builds/414.92.202308032115-0/x86_64/rhcos-414.92.202308032115-0-openstack.x86_64.qcow2.gz?sha256=cb38a9daa14e746f1b6fe4033b583777e86bcea3b44c2a95b3516304fb358ac2'
level=fatal msg=failed to fetch Terraform Variables: failed to generate asset "Terraform Variables": failed to get openstack Terraform variables: gzip: invalid checksum

[openshift-ci]

@mkowalski: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
ci/prow/e2e-openstack	88fffa2	link	false	/test e2e-openstack

Full PR test history. Your PR dashboard.

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. I understand the commands that are listed here.

[mkowalski]

/jira refresh
/retest-required

[openshift-ci-robot]

@mkowalski: This pull request references Jira Issue OCPBUGS-17787, 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 (4.14.0) matches configured target version for branch (4.14.0)
• bug is in the state ASSIGNED, which is one of the valid states (NEW, ASSIGNED, POST)

Requesting review from QA contact:
/cc @anuragthehatter

In response to this:

/jira refresh
/retest-required

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.

[mkowalski]

/cherry-pick release-4.14

[openshift-cherrypick-robot]

@mkowalski: once the present PR merges, I will cherry-pick it on top of release-4.14 in a new PR and assign it to you.

In response to this:

/cherry-pick release-4.14

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-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cybertron, mkowalski, yuqi-zhang

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:

• OWNERS [yuqi-zhang]

Approvers can indicate their approval by writing /approve in a comment
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[openshift-ci-robot]

@mkowalski: Jira Issue OCPBUGS-17787: All pull requests linked via external trackers have merged:

• openshift/machine-config-operator#3870

Jira Issue OCPBUGS-17787 has been moved to the MODIFIED state.

In response to this:

Using sysctl to modify paths containing dots is known to cause issues due to the fact that sysctl blindly assumes that dot is always a separator and is changed to /.

This is a problem when we want to configure a network interface containing a dot in its name, e.g. bond0.354, because net.ipv4.conf.bond0.354.forwarding=1 expands to
/proc/sys/net/ipv4/conf/bond0/354/forwarding when in reality it should be /proc/sys/net/ipv4/conf/bond0.354/forwarding.

To remediate this we are changing the call from
sysctl -w net.ipv4.conf.bond0.354.forwarding=1 to echo "1" > /proc/sys/net/ipv4/conf/bond0.354/forwarding as there is no simple way to change the behaviour of sysctl.

In the current form the call is breaking the script as writing a value to a non-existing path returns an error cannot stat [...] No such file or directory

Fixes: OCPBUGS-17787

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-cherrypick-robot]

@mkowalski: new pull request created: #3881

In response to this:

/cherry-pick release-4.14

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.