feat: support N nginx ingresses

[tperdue321]

Enhancement proposal: #2001

Modifications:

• update the Nginx datatype to have a field called AdditionalStableIngresses to allow for 1-N stable ingresses instead of just 1. This naming convention is modeled after AdditionalIngressAnnotations
• modify the SetWeight method to create a canary for each stable ingress and apply new weight to all canary ingresses.
• update validations to validate all stable ingresses.
• designed to be fully backwards compatible.

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional with a list of types and scopes found here, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed my commits with DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.

[codecov]

Codecov Report

Patch coverage: 77.45% and no project coverage change.

Comparison is base (aa47e41) 81.52% compared to head (a57447a) 81.52%.

❗ Current head a57447a differs from pull request most recent head afd6d13. Consider uploading reports for the commit afd6d13 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2467   +/-   ##
=======================================
  Coverage   81.52%   81.52%           
=======================================
  Files         133      133           
  Lines       19866    19944   +78     
=======================================
+ Hits        16195    16259   +64     
- Misses       2836     2849   +13     
- Partials      835      836    +1     

Impacted Files	Coverage Δ
rollout/trafficrouting/nginx/nginx.go	78.40% <73.01%> (-2.37%)	⬇️
.../apis/rollouts/validation/validation_references.go	90.43% <75.00%> (-0.22%)	⬇️
utils/ingress/ingress.go	98.04% <82.60%> (-1.96%)	⬇️
rollout/controller.go	81.58% <84.61%> (+0.81%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report in Codecov by Sentry.
📢 Do you have feedback about the report comment? Let us know in this issue.

[github-actions]

Go Published Test Results

1 930 tests   1 930 ✔️  2m 35s ⏱️
   118 suites         0 💤
       1 files           0 ❌

Results for commit afd6d13.

♻️ This comment has been updated with latest results.

[github-actions]

E2E Tests Published Test Results

    4 files      4 suites   3h 15m 21s ⏱️
  95 tests   82 ✔️   5 💤   8 ❌
392 runs  360 ✔️ 20 💤 12 ❌

For more details on these failures, see this check.

Results for commit afd6d13.

♻️ This comment has been updated with latest results.

[ssanders1449]

@zachaller - Is this targeted for 1.4?

[zachaller]

No I just cut 1.4 due to the timeline we are tracking with argocd but with this and the alb support also wanting the same features I plan on getting it megred in for 1.5 I do want to spend a little time looking at how we did it with istio and see if it makes sense to mimic that here vs the additionalIngesses and or for the alb as well to see if having a route concept makes sense or not, but I am pretty on board for the feature.

[zachaller]

@ssanders1449 also note I do want to follow a much more open release schedule here is the proposal https://github.com/argoproj/argo-rollouts/pull/2446/files

[tperdue321]

SonarCloud Quality Gate failed.   

0 Bugs 0 Vulnerabilities 0 Security Hotspots 36 Code Smells

No Coverage information 43.6% Duplication

I'm working on reducing duplication today

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
9 Code Smells

No Coverage information
10.0% Duplication

[zachaller]

@tperdue321 Can I get you to resolve conflicts before I review?

[zachaller]

Also can you update from master to resolve conflicts.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
16 Code Smells

No Coverage information
14.0% Duplication