feat(prow): auto-inject metadata labels to kubevirt prowjobs

[Aneesh-Hegde]

What this PR does / why we need it:
Injects explicit metadata labels (ci.kubevirt.io/k8s-version, ci.kubevirt.io/sig, and ci.kubevirt.io/category) into KubeVirt ProwJobs. This allows the prow-exporter to scrape these dimensions, enabling Grafana admins to filter metrics using clean Prometheus label queries instead of relying on fragile regex matching against the job_name.

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #4733

Special notes for your reviewer:
To avoid human error and preserve existing YAML formatting/comments, I used an automated ruamel.yaml Python script to parse the name strings and inject the labels across the jobs/kubevirt/kubevirt/ directory.

Questions for Maintainers:
I currently extracted Version, SIG, and Category based on the issue description. Looking at the job names, I could also extract architecture (arm64/s390x) and provider/hardware (kind/vgpu/sriov). Would you like those added to this PR, or should we keep the scope narrow for now?

Checklist

This checklist is not enforcing, but it's a reminder of items that could be relevant to every PR.
Approvers are expected to review this list.

• Design: A design document was considered and is present (link) or not required
• PR: The PR description is expressive enough and will help future contributors
• Code: Write code that humans can understand and Keep it simple
• Refactor: You have left the code cleaner than you found it (Boy Scout Rule)
• Upgrade: Impact of this change on upgrade flows was considered and addressed if required
• Testing: New code requires new unit tests. New features and bug fixes require at least on e2e test
• Documentation: A user-guide update was considered and is present (link) or not required. You want a user-guide update if it's a user facing feature / API change.
• Community: Announcement to kubevirt-dev was considered

Release note:

NONE

[sourcery-ai]

Sorry @Aneesh-Hegde, your pull request is larger than the review limit of 150000 diff characters

[kubevirt-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

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Details

Needs approval from an approver in each of these files:

• github/ci/prow-deploy/files/jobs/kubevirt/kubevirt/OWNERS

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[kubevirt-bot]

Hi @Aneesh-Hegde. Thanks for your PR.

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[Aneesh-Hegde]

/cc @dhiller

[kubevirt-bot]

PR needs rebase.

Details

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[Aneesh-Hegde]

Hey @dhiller ! Since this PR modifies over 2,000 lines, I want to make reviewing it as painless as possible.

I did not hand edit these files. To prevent human error and perfectly preserve your existing YAML formatting and comments, I wrote a Python script using the ruamel.yaml library (which preserves AST).

Instead of reading the massive diff, you only need to review the regex logic in this script.

Click here to view the exact Python script used

Details

import os
import re
from ruamel.yaml import YAML

def process_yaml(filepath):
    yaml = YAML()
    yaml.allow_duplicate_keys = True
    yaml.preserve_quotes = True
    yaml.indent(mapping=2, sequence=2, offset=0)
    yaml.width = 4096 

    try:
        with open(filepath, 'r') as f:
            data = yaml.load(f)
    except Exception as e:
        return

    if not data or not isinstance(data, dict):
        return

    modified = False
    job_types = ['presubmits', 'postsubmits', 'periodics']
    
    for j_type in job_types:
        if j_type in data and isinstance(data[j_type], dict):
            for repo, jobs in data[j_type].items():
                if not jobs or not isinstance(jobs, list):
                    continue

                for job in jobs:
                    if not isinstance(job, dict) or 'name' not in job:
                        continue
                    
                    job_name = job['name']
                    new_labels = {}

                    # 1. Extract Version
                    k8s_match = re.search(r'(?:k8s|kind)-(\d+\.\d+)', job_name)
                    if k8s_match:
                        new_labels['ci.kubevirt.io/k8s-version'] = k8s_match.group(1)

                    # 2. Extract SIG
                    sig_match = re.search(r'sig-([a-zA-Z0-9]+)', job_name)
                    if sig_match:
                        new_labels['ci.kubevirt.io/sig'] = sig_match.group(1)

                    # 3. Extract Category
                    if '-e2e-' in job_name:
                        new_labels['ci.kubevirt.io/category'] = 'e2e'
                    elif '-unit-' in job_name:
                        new_labels['ci.kubevirt.io/category'] = 'unit'
                    elif '-build-' in job_name:
                        new_labels['ci.kubevirt.io/category'] = 'build'
                    elif '-lint' in job_name:
                        new_labels['ci.kubevirt.io/category'] = 'lint'

                    if new_labels:
                        if 'labels' not in job:
                            job['labels'] = {}
                        for key, val in new_labels.items():
                            if key not in job['labels']:
                                job['labels'][key] = val
                                modified = True

    if modified:
        with open(filepath, 'w') as f:
            yaml.dump(data, f)

def main():
    for filename in os.listdir('.'):
        if filename.endswith('.yaml'):
            process_yaml(filename)

if __name__ == '__main__':
    main()