Merge pull request #958 from Mohanraj209/MOSIP-36541

[MOSIP-36541] Added a documentation to expose an additional port.

docs/design/enable-new-port.md

@@ -0,0 +1,83 @@
+# Expose an additional port, such as 5433 or any other, for a service in a specific namespace.
+
+### steps:
+
+1. Add the Istio Gateway and Virtual service by deploying the istio-addons and update the configuration as given below.
+
+   * Gateway:
+   ```
+   spec:
+     selector:
+       istio: ingressgateway-internal
+     servers:
+       - hosts:
+         - <hostname>    ## hostname will be checked only if "protocol" is set to HTTP, not for TCP protocol
+       port:
+         name: <PortName>
+         number: <port>               
+         protocol: TCP 
+   ```
+
+   * Virtual-service:
+   ```
+   gateways:
+     - <gateway-name>
+     hosts:
+     - '*'
+     tcp:
+     - match:
+       - port: <port>                   ## ingress gateway container port               
+       route:
+       - destination:
+           host: <service-name>
+           port: 
+           number: 5432              ## pod's service port
+   ```
+
+2. Update the IstioOperator (IOP) configuration as given below by editing the IOP in the istio-system namespace.
+
+  ```
+  $ kubectl -n istio-system edit istiooperator istio-operators-mosip
+  ```  
+
+   ```
+   k8s:
+     service:
+       ports:
+         - name: <PortName>
+           nodePort: <nodeport>     
+           port: <port>         
+           protocol: TCP
+           targetPort: <port>
+   ```
+
+3. Update the configuration as given below within the `stream` block of  the nginx.conf file of nginx node. 
+   ```
+   upstream <backend-group-name> {
+      server <server1-ip>:<nodeport>;
+                server <server2-ip>:<nodeport>;
+                server <server3-ip>:<nodeport>;
+                server <server4-ip>:<nodeport>;
+                server <server5-ip>:<nodeport>;
+                server <server6-ip>:<nodeport>;
+                server <server7-ip>:<nodeport>;
+                server <server8-ip>:<nodeport>;
+
+    }
+   
+   Note: The upstream block is usually followed by a server block where the traffic from clients is forwarded to the backend upstream group.  
+   server{
+        listen <cluster-nginx-internal-ip>:<port>;
+        proxy_pass <backend-group-name>;
+    }
+   ```
+
+4. Restart the Nginx service.
+   ```
+   sudo systemctl restart nginx
+   ```  
+
+5. Expose the port and nodePort from the AWS cloud and UFW firewall.
+   * < port >: needs to be exposed for the nginx node. 
+   * < nodeport >: needs to be exposed for all the k8's cluster nodes.
+