tests: Separates DNS hosts entries test

[claudiubelu]

At the moment, Windows cannot mount individual files into Containers, which means
that the Kubelet-managed hosts file cannot be mounted into the Container, causing
the "should provide DNS for the cluster" test to fail.

This test separates the hosts entries checks from the mentioned test to a new test.

What type of PR is this?

/kind failing-test
/kind feature

/sig testing
/sig windows

What this PR does / why we need it:

Which issue(s) this PR fixes:

At the moment, mounting individual files in Docker Containers on Windows is not possible, and because of this, Kubelet cannot mount and manage the Containers' hosts files.

Because of this, the test should provide DNS for the cluster will fail when using Windows Containers because the hosts entries cannot be validated.

This patch splits the /etc/hosts file entries validation into a separate test, which is a necessary step in order to have the mentioned test pass on Windows.

Related issue: #70189

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

The new test ``[sig-network] DNS should provide /etc/hosts entries for the cluster [LinuxOnly] [Conformance]`` will validate the host entries set in the ``/etc/hosts`` file (pod's FQDN and hostname), which should be managed by Kubelet.

The test has the tag ``[LinuxOnly]`` because individual files cannot be mounted in Windows Containers, which means that it cannot pass using Windows nodes. 

[k8s-ci-robot]

Hi @BCLAU. 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.

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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.

[claudiubelu]

/assign @bgrant0607 @danwinship

[danwinship]

/ok-test-test
/lgtm

[danwinship]

/ok-to-test

[claudiubelu]

/test pull-kubernetes-e2e-gce

[dims]

/sig network

[dims]

@kubernetes/sig-network-pr-reviews @thockin @dcbw @caseydavenport Can the sig-network please sign off on this conformance related change?

[PatrickLang]

/milestone v1.14

[bowei]

/approve
/lgtm

[bowei]

Looks like someone from conformance needs to do the final approval.

[bgrant0607]

Changes to the set of conformance tests should have release notes. Please add one that briefly explains what this change is to someone who cares about what conformance tests are run, passing/failing, etc., such as a Kubernetes provider or someone building their own cluster "the hard way".

That should be added to our release-note guidance:
kubernetes/community#484

[bgrant0607]

@bowei The GCE/GKE-specific tests of google.com and metadata shouldn't be in the conformance test. Please move it to a non-conformance e2e test.

[bgrant0607]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bclau, bgrant0607, bowei

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:

• test/conformance/testdata/OWNERS [bgrant0607]
• test/e2e/network/OWNERS [bgrant0607,bowei]

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

[bgrant0607]

FYI, I filed an issue proposing that any conformance test that checks the provider should die and fail: #74432

[bgrant0607]

/hold

[bgrant0607]

The hold can be removed once a release note is written

[claudiubelu]

I've added a Release Note, but I'm not particularly sure about its formatting, if I should break the lines or not.

[bowei]

@prameshj can you take a look at moving the GCE-specific tests out of the conformance?

[marpaia]

In the PR description, the release note should go in the stanza under "Does this PR introduce a user-facing change?" where it currently says "NONE".

[claudiubelu]

Strange. For some reason, it didn't save my edit. Luckily, the message was still there when I tried to edit it again.

[adelina-t]

/lgtm
/hold cancel