scripts/test_images.sh: refactor to import job into the prow infrastructure

[ivanvc]

While importing the release tests into the Prow infrastructure, after some exploration, I found that the current script didn't work correctly because it allows an input environment variable "IMAGE," which in the Prow infra points to the image from the container. This made the scripts/test_images.sh script fail. So, I took an opportunity to rewrite the script in a more modular way while fixing this issue.

• Wrap script in functions, add a main function, and call them from it.
• Make environment variables local inside the function scope to avoid unexpected behaviors by the running environment-supplied variables.
• Fix the typo in the "REPOSITORY" environment variable.
• Rename the input "IMAGE" to "TEST_IMAGE" to avoid clashing with the environment variable from the Prow infrastructure.

Please read https://github.com/etcd-io/etcd/blob/main/CONTRIBUTING.md#contribution-flow.

[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

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 68.83%. Comparing base (dd60559) to head (0ac24a8).
Report is 4 commits behind head on main.

Additional details and impacted files

see 14 files with indirect coverage changes

@@            Coverage Diff             @@
##             main   #19305      +/-   ##
==========================================
- Coverage   68.84%   68.83%   -0.02%     
==========================================
  Files         420      420              
  Lines       35693    35693              
==========================================
- Hits        24573    24568       -5     
- Misses       9698     9702       +4     
- Partials     1422     1423       +1     

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update dd60559...0ac24a8. Read the comment docs.

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-release-tests

[ivanvc]

/test pull-etcd-verify

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ivanvc

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:

• scripts/OWNERS [ivanvc]

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

[ivanvc]

/test pull-etcd-release-tests pull-etcd-verify

[ivanvc]

/test pull-etcd-integration-1-cpu-amd64

[ivanvc]

Let me know if you want me to start a fresh PR. I reused the one I used to test that the prow job worked.