jaeger-endpoint feature for non-agent trace collectors

[timmysilv]

https://github.com/jaegertracing/jaeger-client-cpp supports both the compact jaeger.thrift format over UDP (meant for local tracing agents) as well as the binary jaeger.thrift format over HTTP, meant for collector deployments. This PR adds support for providing a collector endpoint when no tracing agents are deployed. I'll rebase and update #6872 accordingly (this should probably be merged first, but it doesn't really matter as long as the second one is updated).

What this PR does / why we need it:

Some cluster deployments may not have tracing agents on every host. If your infrastructure only has collectors listening over TCP, ingress-nginx cannot currently export compatible traces. This changes enables TCP endpoint support. As mentioned in the documentation change, when both are provided, this endpoint takes priority (that decision is in the jaeger client, not in ingress-nginx).

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Which issue/s this PR fixes

How Has This Been Tested?

I have added e2e and unit test cases to show that tracing is enabled as expected. I also ran this code locally and verified that /etc/nginx/opentracing.json was updated accordingly (and that the collector I have running received traces over TCP as expected).

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added tests to cover my changes.
• All new and existing tests passed.

[k8s-ci-robot]

Hi @timmysilv. 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.

[timmysilv]

I spent a bit of time looking into this but I'm pretty sure this call to getaddrinfo fails for SOCK_STREAM only (jaegerEndpoint uses TCP which might explain why this fails but the jaegerCollectorHost tests pass). The difference in calls starts here. Maybe the way to get this to pass in tests is blindingly obvious but I'm not seeing it so I've just commented out the test for now. I also read that the e2e image might need the bind-tools apk addition, but I tried that and it still failed.

[ElvinEfendi]

/ok-to-test

[ElvinEfendi]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ElvinEfendi, timmysilv

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 [ElvinEfendi]

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