Resolve "Integrate Keycloak package with BigBang"

Summary

This is the initial release of Keycloak with BigBang.
IMPORTANT NOTE: Keycolak is only intended to be deployed by itself with only the core apps. When keycloak is enabled the core apps conditionally deploy with a separate *.admin.* domain like this *.admin.bigbang.dev. Also, when Keycloak is enabled an additional server with tls.mode PASSTHROUGH is conditionally added to the istio ingressgateway.

Zach Williamson and Cameron Banowsky from the CNAP team have been actively testing this branch with their new P1 SSO deployments. All known issues have been resolved.

Closes #291 (closed)

chart/templates/istio/controlplane/values.yaml

@@ -23,4 +23,20 @@ ingress:
     port: 8080
     namespace: authservice
 {{- end }}
-{{- end -}}
+
+{{- $hosts := .Values.istio.ingress.passthrough_hosts }}
+{{- if $hosts }}
+extraServers:
+- port:
+    name: https-passthrough
+    protocol: HTTPS
+    number: 443
+  hosts:
+    {{- range $host := $hosts }}
+    - {{ $host }}.{{ $.Values.hostname }}
+    {{- end }}
+  tls:
+    credentialName: "null"
+    mode: PASSTHROUGH
+{{- end }}
+{{- end -}}
\ No newline at end of file