Add gateway mode support and custom nginx configuration to OPEA nginx…

helm-charts/common/nginx/README.md

@@ -2,6 +2,77 @@
 
 Helm chart for deploying OPEA nginx service.
 
-## Using nginx chart
+## Integration with OPEA Applications
 
-E2E charts for OPEA applications should provide ConfigMap of name `{{ .Release.Name }}-nginx-config` with the required environment variables to configure [OPEA nginx microservice](https://github.com/opea-project/GenAIComps/blob/main/comps/nginx/nginx.conf.template).
+When used as a simple proxy within OPEA application charts (ChatQnA, CodeGen, etc.), parent charts should provide a ConfigMap named `{{ .Release.Name }}-nginx-config` containing environment variables for the [OPEA nginx microservice](https://github.com/opea-project/GenAIComps/blob/main/comps/third_parties/nginx/src/nginx.conf.template).
+
+## Gateway Mode (Central Router)
+
+The nginx chart can be configured to act as a central gateway/router for OPEA services. This mode provides:
+
+- Service routing to multiple OPEA microservices
+- Custom nginx configuration template support
+- Health check endpoints
+- Optional ingress and monitoring support
+
+### How to Use Gateway Mode
+
+Gateway mode is designed to be used within E2E (end-to-end) charts. The pattern is:
+
+1. **Create an E2E chart** that includes nginx as a dependency
+2. **Define environment variables** in your E2E chart's `{{ .Release.Name }}-nginx-config` ConfigMap
+3. **Use custom nginx template** with environment variable substitution
+
+### Example Implementation
+
+```yaml
+# In your E2E chart's templates/nginx-config.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ .Release.Name }}-nginx-config
+data:
+  FRONTEND_SERVICE_IP: "ui.ui.svc.cluster.local"
+  FRONTEND_SERVICE_PORT: "5173"
+  CHATQNA_SERVICE_IP: "chatqna.chatqna.svc.cluster.local"
+  CHATQNA_SERVICE_PORT: "8888"
+  EMBEDDING_SERVICE_IP: "embedding-usvc.default.svc.cluster.local"
+  EMBEDDING_SERVICE_PORT: "6000"
+  DATAPREP_SERVICE_IP: "data-prep.default.svc.cluster.local"
+  DATAPREP_SERVICE_PORT: "6007"
+  # ... other service endpoints
+```
+
+```yaml
+# In your E2E chart's values.yaml
+nginx:
+  nginxConfig:
+    enabled: true
+    template: |
+      server {
+        location / {
+          proxy_pass http://${FRONTEND_SERVICE_IP}:${FRONTEND_SERVICE_PORT};
+        }
+        location /v1/chatqna {
+          proxy_pass http://${CHATQNA_SERVICE_IP}:${CHATQNA_SERVICE_PORT}/v1/chatqna;
+        }
+        location /v1/embeddings {
+          proxy_pass http://${EMBEDDING_SERVICE_IP}:${EMBEDDING_SERVICE_PORT}/v1/embeddings;
+        }
+        location /v1/dataprep {
+          proxy_pass http://${DATAPREP_SERVICE_IP}:${DATAPREP_SERVICE_PORT}/v1/dataprep;
+        }
+        # ... other routes
+      }
+```
+
+See `gateway-values.yaml` for a complete example template.
+
+## Deployment Modes
+
+This chart supports two deployment modes:
+
+- **Simple Proxy Mode** (default): Acts as a reverse proxy within OPEA application charts
+- **Gateway Mode**: Central router providing unified access to multiple OPEA services (used within E2E charts)
+
+All existing deployments continue to work unchanged. Gateway mode requires creating an E2E chart that follows the pattern shown above.

helm-charts/common/nginx/templates/configmap.yaml

@@ -0,0 +1,14 @@
+# Copyright (C) 2024 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+{{- if .Values.nginxConfig.enabled }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ include "nginx.fullname" . }}-template-config
+  labels:
+    {{- include "nginx.labels" . | nindent 4 }}
+data:
+  default.conf.template: |
+{{- .Values.nginxConfig.template | nindent 4 }}
+{{- end }}

helm-charts/common/nginx/templates/deployment.yaml

@@ -33,6 +33,12 @@ spec:
         {{- toYaml .Values.podSecurityContext | nindent 8 }}
       containers:
         - name: {{ .Chart.Name }}
+          {{- if .Values.customCommand.enabled }}
+          command:
+            {{- toYaml .Values.customCommand.command | nindent 12 }}
+          args:
+            {{- toYaml .Values.customCommand.args | nindent 12 }}
+          {{- end }}
           envFrom:
             - configMapRef:
                 name: {{ .Release.Name }}-nginx-config
@@ -61,13 +67,29 @@ spec:
           {{- end }}
           resources:
             {{- toYaml .Values.resources | nindent 12 }}
-          {{- with .Values.volumeMounts }}
+          {{- if or .Values.volumeMounts .Values.nginxConfig.enabled }}
           volumeMounts:
+            {{- if .Values.nginxConfig.enabled }}
+            - name: nginx-conf
+              mountPath: /etc/nginx/templates/
+            {{- end }}
+            {{- with .Values.volumeMounts }}
             {{- toYaml . | nindent 12 }}
+            {{- end }}
           {{- end }}
-      {{- with .Values.volumes }}
+      {{- if or .Values.volumes .Values.nginxConfig.enabled }}
       volumes:
+        {{- if .Values.nginxConfig.enabled }}
+        - name: nginx-conf
+          configMap:
+            name: {{ include "nginx.fullname" . }}-template-config
+            items:
+              - key: default.conf.template
+                path: default.conf.template
+        {{- end }}
+        {{- with .Values.volumes }}
         {{- toYaml . | nindent 8 }}
+        {{- end }}
       {{- end }}
       {{- with .Values.nodeSelector }}
       nodeSelector:

helm-charts/common/nginx/templates/ingress.yaml

@@ -0,0 +1,46 @@
+# Copyright (C) 2024 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+{{- if .Values.ingress.enabled }}
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: {{ include "nginx.fullname" . }}
+  labels:
+    {{- include "nginx.labels" . | nindent 4 }}
+  {{- with .Values.ingress.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+spec:
+  {{- with .Values.ingress.className }}
+  ingressClassName: {{ . }}
+  {{- end }}
+  {{- if .Values.ingress.tls }}
+  tls:
+    {{- range .Values.ingress.tls }}
+    - hosts:
+        {{- range .hosts }}
+        - {{ . | quote }}
+        {{- end }}
+      secretName: {{ .secretName }}
+    {{- end }}
+  {{- end }}
+  rules:
+    {{- range .Values.ingress.hosts }}
+    - host: {{ .host | quote }}
+      http:
+        paths:
+          {{- range .paths }}
+          - path: {{ .path }}
+            {{- with .pathType }}
+            pathType: {{ . }}
+            {{- end }}
+            backend:
+              service:
+                name: {{ include "nginx.fullname" $ }}
+                port:
+                  number: {{ $.Values.service.port }}
+          {{- end }}
+    {{- end }}
+{{- end }}

helm-charts/common/nginx/templates/servicemonitor.yaml

@@ -0,0 +1,18 @@
+# Copyright (C) 2024 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+{{- if .Values.global.monitoring }}
+apiVersion: monitoring.coreos.com/v1
+kind: ServiceMonitor
+metadata:
+  name: {{ include "nginx.fullname" . }}
+  labels:
+    release: {{ .Values.global.prometheusRelease }}
+spec:
+  selector:
+    matchLabels:
+      {{- include "nginx.selectorLabels" . | nindent 6 }}
+  endpoints:
+  - port: nginx
+    interval: 5s
+{{- end }}

helm-charts/common/nginx/values.yaml

@@ -102,3 +102,25 @@ global:
   # If set, it will overwrite serviceAccount.name.
   # If set, and serviceAccount.create is false, it will assume this service account is already created by others.
   sharedSAName: ""
+
+# Custom nginx configuration (optional)
+# Allows overriding the default nginx configuration template
+nginxConfig:
+  enabled: false
+  template: ""
+
+# Custom container startup commands (optional)
+# Allows overriding default container startup behavior
+customCommand:
+  enabled: false
+  command: []
+  args: []
+
+
+# Ingress configuration (optional, disabled by default)
+ingress:
+  enabled: false
+  className: ""
+  annotations: {}
+  hosts: []
+  tls: []