Add initial Keycloak Helm chart with comprehensive configuration

This commit introduces a complete Helm chart for deploying Keycloak on
Kubernetes. The chart includes a variety of configurations such as
service and ingress definitions, metrics exposure, resource limits, and
autoscaling options.

Key features include:
- Full support for PostgreSQL as a database, configurable through chart
  values.
- Ingress resources for external access, including support for TLS and
  admin interfaces.
- Options to use custom configurations and initialization scripts via
  ConfigMaps.
- Metrics service for Prometheus integration, alongside ServiceMonitor
  configurations for Kubernetes monitoring.
- Enhanced environment variables management, including secret handling
  for sensitive data like passwords.

These changes provide a robust foundation for deploying Keycloak in
both development and production environments. Users should be aware
that this initial setup gives flexibility for customization, but care
should be taken when altering default configurations to ensure
compatibility with existing deployments.

charts/keycloak/templates/pdb.yaml

@@ -0,0 +1,28 @@
+{{- /*
+Copyright Broadcom, Inc. All Rights Reserved.
+SPDX-License-Identifier: APACHE-2.0
+*/}}
+
+{{- if .Values.pdb.create }}
+apiVersion: {{ include "common.capabilities.policy.apiVersion" . }}
+kind: PodDisruptionBudget
+metadata:
+  name: {{ template "common.names.fullname" . }}
+  namespace: {{ include "common.names.namespace" . | quote }}
+  labels: {{- include "common.labels.standard" ( dict "customLabels" .Values.commonLabels "context" $ ) | nindent 4 }}
+    app.kubernetes.io/component: keycloak
+  {{- if .Values.commonAnnotations }}
+  annotations: {{- include "common.tplvalues.render" ( dict "value" .Values.commonAnnotations "context" $ ) | nindent 4 }}
+  {{- end }}
+spec:
+  {{- if .Values.pdb.minAvailable }}
+  minAvailable: {{ .Values.pdb.minAvailable }}
+  {{- end }}
+  {{- if or .Values.pdb.maxUnavailable ( not .Values.pdb.minAvailable ) }}
+  maxUnavailable: {{ .Values.pdb.maxUnavailable | default 1 }}
+  {{- end }}
+  {{- $podLabels := include "common.tplvalues.merge" ( dict "values" ( list .Values.podLabels .Values.commonLabels ) "context" . ) }}
+  selector:
+    matchLabels: {{- include "common.labels.matchLabels" ( dict "customLabels" $podLabels "context" $ ) | nindent 6 }}
+      app.kubernetes.io/component: keycloak
+{{- end }}