refactor: migrate ingress definition out of beta (#679)

### Description of the change

Redesigned ingress configuration to align better with implicit best practices.

### Benefits

- Smarter defaults
- More tests
- Remove [deprecated API Versions](extensions/v1beta1) (e.g. `extensions/v1beta1`) and always use `networking.k8s.io/v1`

### Possible drawbacks

Hopefully 🙃 none

### Applicable issues

fix #674

### Additional information

- Define `ingress.annotations` via helpers
- Move tests from `tests/deployment` to `tests/ingress`
- Use own tests file for ingress tpl tests
- Ensure defaults of `path` and `pathType` are always rendered
- Set top-level default value for `ingress. pathType`
- Change default of `ingress.hosts[0].paths` to `[]` to ensure proper rendering via template

### ⚠ BREAKING

I think all of these changes should be backward comp with existing ingress definitions, but surely worth highlighting in the changelog of the release.

### Checklist

<!-- [Place an '[X]' (no spaces) in all applicable fields. Please remove unrelated fields.] -->

- [x] Parameters are documented in the `values.yaml` and added to the `README.md` using [readme-generator-for-helm](https://github.com/bitnami-labs/readme-generator-for-helm)
- [x] Breaking changes are documented in the `README.md`
- [x] Templating unittests are added

Co-authored-by: justusbunsi <justusbunsi@noreply.gitea.com>
Co-authored-by: justusbunsi <sk.bunsenbrenner@gmail.com>
Reviewed-on: https://gitea.com/gitea/helm-gitea/pulls/679
Co-authored-by: pat-s <patrick.schratz@gmail.com>
Co-committed-by: pat-s <patrick.schratz@gmail.com>

templates/gitea/ingress.yaml

@@ -1,15 +1,7 @@
 {{- if .Values.ingress.enabled -}}
 {{- $fullName := include "gitea.fullname" . -}}
 {{- $httpPort := .Values.service.http.port -}}
-{{- $apiVersion := "extensions/v1beta1" -}}
-{{- if .Values.ingress.apiVersion -}}
-{{- $apiVersion = .Values.ingress.apiVersion -}}
-{{- else if .Capabilities.APIVersions.Has "networking.k8s.io/v1/Ingress" -}}
-{{- $apiVersion = "networking.k8s.io/v1" }}
-{{- else if .Capabilities.APIVersions.Has "networking.k8s.io/v1beta1/Ingress" -}}
-{{- $apiVersion = "networking.k8s.io/v1beta1" }}
-{{- end }}
-apiVersion: {{ $apiVersion }}
+apiVersion: networking.k8s.io/v1
 kind: Ingress
 metadata:
   name: {{ $fullName }}
@@ -23,6 +15,8 @@ metadata:
 spec:
 {{- if .Values.ingress.className }}
   ingressClassName: {{ tpl .Values.ingress.className . }}
+{{- else if .Values.ingress.ingressClassName }}
+  ingressClassName: {{ tpl .Values.ingress.ingressClassName . }}
 {{- end }}
 {{- if .Values.ingress.tls }}
   tls:
@@ -39,21 +33,34 @@ spec:
     - host: {{ tpl .host $ | quote }}
       http:
         paths:
+          {{- if .paths }}
           {{- range .paths }}
-          - path: {{ .path }}
-            {{- if and .pathType (eq $apiVersion "networking.k8s.io/v1") }}
-            pathType: {{ .pathType }}
-            {{- end }}
+          {{- if kindIs "string" . }}
+          - path: {{ . }}
+            pathType: {{ default "Prefix" $.Values.ingress.pathType }}
+            backend:
+              service:
+                name: {{ $fullName }}-http
+                port:
+                  number: {{ $httpPort }}
+          {{- else }}
+          - path: {{ .path | default "/" }}
+            pathType: {{ .pathType | default "Prefix" }}
+            backend:
+              service:
+                name: {{ $fullName }}-http
+                port:
+                  number: {{ $httpPort }}
+          {{- end }}
+          {{- end }}
+          {{- else }}
+          - path: "/"
+            pathType: "Prefix"
             backend:
-            {{- if eq $apiVersion "networking.k8s.io/v1" }}
               service:
                 name: {{ $fullName }}-http
                 port:
                   number: {{ $httpPort }}
-            {{- else }}
-              serviceName: {{ $fullName }}-http
-              servicePort: {{ $httpPort }}
-            {{- end }}
           {{- end }}
     {{- end }}
 {{- end }}