fix: Drop host: localhost in probes to better fulfill PSA

[mkilchhofer]

What type of PR is this?

/kind bug

What this PR does / why we need it:

In the PSS (pod security standards), starting for Kubernetes >=1.34, it is advised not to use the host field.

The Baseline policy is aimed at ease of adoption for common containerized workloads while preventing known privilege escalations. This policy is targeted at application operators and developers of non-critical applications. The following listed controls should be enforced/disallowed:

Control	Policy
...	...
Host Probes / Lifecycle Hooks (v1.34+)	The Host field in probes and lifecycle hooks must be disallowed. Restricted Fields spec.containers[*].livenessProbe.httpGet.host spec.containers[*].readinessProbe.httpGet.host spec.containers[*].startupProbe.httpGet.host spec.containers[*].livenessProbe.tcpSocket.host spec.containers[*].readinessProbe.tcpSocket.host spec.containers[*].startupProbe.tcpSocket.host spec.containers[*].lifecycle.postStart.tcpSocket.host spec.containers[*].lifecycle.preStop.tcpSocket.host spec.containers[*].lifecycle.postStart.httpGet.host spec.containers[*].lifecycle.preStop.httpGet.host spec.initContainers[*].livenessProbe.httpGet.host spec.initContainers[*].readinessProbe.httpGet.host spec.initContainers[*].startupProbe.httpGet.host spec.initContainers[*].livenessProbe.tcpSocket.host spec.initContainers[*].readinessProbe.tcpSocket.host spec.initContainers[*].startupProbe.tcpSocket.host spec.initContainers[*].lifecycle.postStart.tcpSocket.host spec.initContainers[*].lifecycle.preStop.tcpSocket.host spec.initContainers[*].lifecycle.postStart.httpGet.host spec.initContainers[*].lifecycle.preStop.httpGet.host Allowed Values Undefined/nil ""
...	...

Source: https://kubernetes.io/docs/concepts/security/pod-security-standards/#baseline

The CSI driver periphery from the CSI ecosystem runs perfectly without these fields (I use AWS EBS CSI and AWS EFS CSI).

Which issue(s) this PR fixes:

n/a

Special notes for your reviewer:

Looks kinda like a regression introduced by:

• feat: add optional healthcheck for node-driver-registrar #1026

/cc: @ajhetherington (since you implemented the mentioned PR)

Does this PR introduce a user-facing change?:

none

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: mkilchhofer
Once this PR has been reviewed and has the lgtm label, please assign xing-yang for approval. For more information see the Code Review Process.

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

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-ci-robot]

Welcome @mkilchhofer!

It looks like this is your first PR to kubernetes-csi/csi-driver-nfs 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes-csi/csi-driver-nfs has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @mkilchhofer. Thanks for your PR.

I'm waiting for a kubernetes-csi member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

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-sigs/prow repository.

[andyzhangx]

latest chart config has changed, pls run "helm package charts/latest/csi-driver-nfs -d charts/latest/" to update tgz file

[mkilchhofer]

Hi @andyzhangx

Thanks for your review. Sure, I added the requested change :)

[mkilchhofer]

I noticed that binding the livenessProbes containers to 127.0.0.1:xyz will not properly expose these containers for the kublets:

$ kubectl get events
...
2m46s       Warning   Unhealthy         pod/csi-nfs-controller-56dd6b6bdc-brdp9   Liveness probe failed: Get "http://192.168.92.34:29652/healthz": dial tcp 192.168.92.34:29652: connect: connection refused
8m          Warning   Unhealthy         pod/csi-nfs-node-4gchq                    Liveness probe failed: Get "http://192.168.92.33:29653/healthz": dial tcp 192.168.92.33:29653: connect: connection refused
3m3s        Warning   Unhealthy         pod/csi-nfs-node-8xwqj                    Liveness probe failed: Get "http://192.168.92.34:29653/healthz": dial tcp 192.168.92.34:29653: connect: connection refused
115s        Warning   Unhealthy         pod/csi-nfs-node-dwbjw                    Liveness probe failed: Get "http://192.168.92.32:29653/healthz": dial tcp 192.168.92.32:29653: connect: connection refused
55s         Warning   Unhealthy         pod/csi-nfs-node-wrx86                    Liveness probe failed: Get "http://192.168.92.31:29653/healthz": dial tcp 192.168.92.31:29653: connect: connection refused
...

Not sure how other drivers implement this (do they bind on 0.0.0.0 ?)

core@k3s-node3 ~ $ sudo netstat -tulpn | egrep '29652|29653'
tcp        0      0 127.0.0.1:29653         0.0.0.0:*               LISTEN      1717676/livenesspro
tcp        0      0 127.0.0.1:29652         0.0.0.0:*               LISTEN      1718505/livenesspro

[k8s-ci-robot]

PR needs rebase.

Details

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-sigs/prow repository.