feat: end to end testing with local provider implementation

[Raffo]

What does it do ?

This pull request implements end to end testing by using a new custom local provider that saves records in memory. The idea behind this is that the new local provider, configured as a webhook, will create records in memory based on the usual Kubernetes resources. The same code exposes a minimal implementation of a DNS server. We can then query directly this minimal DNS server to verify that external DNS did its job. This idea allows us to implement end-to-end testing without having to issue certificates or creating real domains. The script can be launched with a bash script, and are wrapped in GitHub actions to be executed on GitHub.

Motivation

We have custom end-to-end testing infrastructure since almost the beginning of this project that I've been maintaining myself. That infrastructure has relied on an AWS account, and a private zone. Unfortunately, due to security requirements, I cannot make that infrastructure available to the bigger project, and that meant that I was always the bottleneck to run end to end tests. The motivation behind this work is to stop using that infrastructure and relying only on kind and local tests.

#5601

More

I went through a lot of ideas also using the /etc/hosts file which is not possible for a number of reasons in Kubernetes and other possible alternatives. This is what I landed to and the code is probably not perfect. I would love anyway for feedback and I will keep this and as draft until I will have received this feedback.

• Yes, this PR title follows Conventional Commits
• Yes, I added unit tests
• Yes, I updated end user documentation accordingly

[k8s-ci-robot]

Skipping CI for Draft Pull Request.
If you want CI signal for your change, please convert it to an actual PR.
You can still manually trigger a test run with /test all

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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

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

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

[coveralls]

Pull Request Test Coverage Report for Build 18979016318

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.08%) to 78.584%

---

Files with Coverage Reduction	New Missed Lines	%
openshift_route.go	1	79.49%

Totals
Change from base Build 18968339179:	-0.08%
Covered Lines:	16017
Relevant Lines:	20382

---

💛 - Coveralls