Improve example readme

Author: ST-DDT

examples/README.md

@@ -1,6 +1,6 @@
 # gRPC spring boot starter Examples
 
-## Local Mode
+## Local Setup
 
 1. Try the local-grpc-server example first run:
 
@@ -16,28 +16,41 @@
 
 3. Visit http://localhost:8080/ to see the result.
 
-## Cloud Mode
+## Cloud Discovery Setup
 
-1. Try the cloud-eureka-server example first run:
+1. Choose a cloud discovery implementation:
+
+   - `consul`
+   - `eureka`
+   - `nacos`
+
+    > **Note:** In your actual application you are free to choose any cloud discovery implementation,
+    > but only the above and `zookeeper` will automatically register the server at the discovery service.
+    > So you might have to write a few extra lines in your server application.
+    > Generic registration support is planned for a future release.
+    > No additional configuration is required for clients.
+
+2. Start the discovery server (only the chosen one):
 
     ````sh
+    # Consul
+    docker run --name=consul -p 8500:8500 consul
+    # Eureka
     ./gradlew :example:cloud-eureka-server:bootRun
+    # Nacos
+    docker run --env MODE=standalone --name nacos -d --rm -p 8848:8848 nacos/nacos-server
     ````
 
-2. Run zipkin-server
-
-    https://github.com/openzipkin/zipkin#quick-start
-
-3. In a different terminal window run:
+3. Insert the selected implementation and start the server application (in a new terminal window):
 
     ````sh
-    ./gradlew :example:cloud-grpc-server:bootRun
+    ./gradlew -Pdiscovery=$discovery :example:cloud-grpc-server:bootRun
     ````
 
-4. In a different terminal window run:
+4. Insert the selected implementation and start the client application (in a new terminal window):
 
     ````sh
-    ./gradlew :example:cloud-grpc-client:bootRun
+    ./gradlew -Pdiscovery=$discovery :example:cloud-grpc-client:bootRun
     ````
 
 5. Visit http://localhost:8080/ to see the result.