Enhance `pokeServer` in helper utilities

[tssurya]

See https://github.com/kubernetes-sigs/network-policy-api/pull/99/commits/63394cc816c1d3f78be860a1faa100a6efd4ca42#r1200872040 for details.

• [ ] See if we can improve the parser to be more accurate on what an error means
• [ ] See if we need to retry the connection errors similar to how its done in netpol v1 tests

/area conformance

[tssurya]

/good-first-issue

[k8s-ci-robot]

@tssurya: This request has been marked as suitable for new contributors.

Guidelines

Please ensure that the issue body includes answers to the following questions:

• Why are we solving this issue?
• To address this issue, are there any code changes? If there are code changes, what needs to be done in the code and what places can the assignee treat as reference points?
• Does this issue have zero to low barrier of entry?
• How can the assignee reach out to you for help?

For more details on the requirements of such an issue, please see here and ensure that they are met.

If this request no longer meets these requirements, the label can be removed by commenting with the /remove-good-first-issue command.

In response to this:

/good-first-issue

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.

[Shin-John]

Can I still assign this to myself? I see that there has been a merged mention.

[flavio-fernandes]

Here is the corrected version of your text:

A humble side note I would like to have along with this issue, which I could have used while encountering a problem during the conformance test:

=== RUN   TestNetworkPolicyV2Conformance/AdminNetworkPolicyEgressSCTP/Should_support_an_'allow-egress'_policy_for_SCTP_protocol;_ensure_rule_ordering_is_respected
    admin-network-policy-core-egress-sctp-rules.go:62: FAILED Command was [/agnhost connect --timeout=3s --protocol=sctp 10.192.0.3:9003]
    admin-network-policy-core-egress-sctp-rules.go:62: Expected connection to succeed from network-policy-conformance-ravenclaw/luna-lovegood-0 to 10.192.0.3, but instead it miserably failed. stderr: OTHER: cannot allocate memory

If you see OTHER: cannot allocate memory while running the test, try increasing the amount of memory on the nodes running the test pods. In my particular test setup, a 16GB VM for 3 nodes was not enough. YMMV (your mileage may vary).