optionally read node and port information from env variables for kube* services

[raghu-nandan-bs]

Enable users to optionally provide node's IP and kubelet, kube-proxy ports.

If users do not wish to run node-problem-detector pod in host network mode, or if the kubelet / kube-proxy's ports are modified from its default value for some reason, we should be able to support configuring endpoint accordingly for performing health checks.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: raghu-nandan-bs / name: Raghu Nandan B S (6163859, 2415e30, f601956)

[k8s-ci-robot]

Welcome @raghu-nandan-bs!

It looks like this is your first PR to kubernetes/node-problem-detector 🎉. 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/node-problem-detector 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 @raghu-nandan-bs. Thanks for your PR.

I'm waiting for a kubernetes 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.

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.

[raghu-nandan-bs]

/hold

[raghu-nandan-bs]

/hold cancel

[vteratipally]

/ok-to-test

[mmiranda96]

Left a couple of comments. One more ask: could you add some unit tests for this new logic in https://github.com/kubernetes/node-problem-detector/blob/master/pkg/healthchecker/types/types_test.go?

[mmiranda96]

To be consistent with the rest of the naming, could you change this variable name to hostIPKey?

[mmiranda96]

Since these values are now public variables, they can be overwritten by other means. The only way I can think of preventing this is to have private strings and public functions that return those private values. Eg.

var kubeletHealthCheckEndpoint string
// Assign the value via setKubeEndpoints

func KubeletHealthCheckEndpoint() string { return kubeletHealthCheckEndpoint }

[mmiranda96]

BTW, you might find https://pkg.go.dev/testing#T.Setenv useful for unit testing OS environment variables.

[mmiranda96]

/lgtm

Thanks for your contribution!

[raghu-nandan-bs]

/assign andyxning

[raghu-nandan-bs]

/unassign andyxning

[raghu-nandan-bs]

/assign vteratipally

[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all PRs.

This bot triages PRs according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the PR is closed

You can:

• Mark this PR as fresh with /remove-lifecycle stale
• Close this PR with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

[raghu-nandan-bs]

/remove-lifecycle stale

[mmiranda96]

/assign @vteratipally

[vteratipally]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mmiranda96, raghu-nandan-bs, vteratipally

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [vteratipally]

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