Introducing GatewayAPI support for Helm

[localleon]

Closes #11621

Adds Gateway API Support to the Nessie Helm Chart

This PR introduces first-class support for the Kubernetes Gateway API (gateway.networking.k8s.io/v1) as an alternative to the existing Ingress configuration. It includes templating, values, documentation, and tests for generating Gateway and HTTPRoute resources.

Key changes:

• New gatewayApi values section with full customization options for Gateways, listeners, TLS, routes, and backend references.
• Templates for Gateway and HTTPRoute resources, including version detection and strict validation.
• Updated README with usage examples and configuration details.
• Added CI values and Helm unittest coverage for default rendering, override behavior, TLS configuration, and custom parentRefs/backends.
• Minor fixes for template newline trimming.

This enables users to expose Nessie using modern Gateway API controllers such as Envoy Gateway, Istio, Traefik, or Kuma.

[localleon]

@adutra please take a look ;-)

[snazy]

@localleon mind signing the CLA?

[localleon]

@localleon mind signing the CLA?

Sure, where do i find instructions on hwo to do it? There's nothing in the CONTRIBUTING.md?

[CLAassistant]

All committers have signed the CLA.

[snazy]

@localleon mind signing the CLA?

Sure, where do i find instructions on hwo to do it? There's nothing in the CONTRIBUTING.md?

You should have seen a link on this PR.

[localleon]

@adutra please take a look again!

$ helm unittest ./
2025/11/19 09:30:31 found symbolic link in path: /home/lraus/nessie/helm/nessie/LICENSE resolves to /home/lraus/nessie/LICENSE. Contents of linked file included and used

### Chart [ nessie ] ./

 PASS   tests/configmap_test.yaml
 PASS   tests/gateway_api_test.yaml
 PASS   tests/logging_storage_test.yaml
 PASS   tests/logging_test.yaml
 PASS   tests/pdb_test.yaml
 PASS   tests/quantity_test.yaml
 PASS   tests/service_monitor_test.yaml

Charts:      1 passed, 1 total
Test Suites: 7 passed, 7 total
Tests:       61 passed, 61 total
Snapshot:    0 passed, 0 total
Time:        596.957069ms

[localleon]

@adutra please recheck the PR. I do not have much time to spend on this issue anymore, but I hope this version will be satisfiable for a first iteration of the feature

[localleon]

Looks like we need to add the GatewayAPI capabilities to the "helm template" commands for CI to work correctly

[adutra]

Looks like we need to add the GatewayAPI capabilities to the "helm template" commands for CI to work correctly

@localleon I fixed a few things in this commit:

https://github.com/adutra/nessie/commit/95db176167287d2e95c0039207514900cdf9cc78

Feel free to cherry-pick, let's see if that makes CI pass.

[localleon]

@adutra cherry-picked your commit and merged latest main

[adutra]

@localleon do you mind rebasing your PR? The CI failure is unrelated to your changes and has been fixed on main.

UPDATE: nevermind, I could do it myself 😅

[adutra]

@localleon in order to move faster I created a separate PR, squashed all your commits and fixed the remaining issues with CI: #11768. Your commit authorship was preserved. I'm closing this one then. Thanks for your contribution!