Working draft

.gitignore

-/myenv
-.DS_Store
\ No newline at end of file
+*/venv
+edge/target/*
+.idea
+.DS_Store

docker-compose.yml

 version: '3.9'
 services:
   usage-sensor:
+    ports:
+      - "5555:5555"
     build:
       context: ./sensors/usage
   temperature-sensor:
+    ports:
+      - "5556:5556"
     build:
       context: ./sensors/temperature

edge/pom.xml

@@ -12,10 +12,11 @@
         <maven.compiler.source>17</maven.compiler.source>
         <maven.compiler.target>17</maven.compiler.target>
     </properties>
-
-<dependency>
-      <groupId>org.zeromq</groupId>
-      <artifactId>jeromq</artifactId>
-      <version>0.6.0</version>
-    </dependency>
-</project>
\ No newline at end of file
+    <dependencies>
+        <dependency>
+            <groupId>org.zeromq</groupId>
+            <artifactId>jeromq</artifactId>
+            <version>0.6.0</version>
+        </dependency>
+    </dependencies>
+</project>

edge/src/main/java/com/fogcomputing/Main.java

-package edge.src.main.java.com.fogcomputing;
+package com.fogcomputing;
 
 import org.zeromq.SocketType;
 import org.zeromq.ZMQ;
 import org.zeromq.ZContext;
 
 public class Main {
-    public static void main(String[] args) throws Exception
-    {
-        try (ZContext context = new ZContext()) {
-            // Socket to talk to clients
-            ZMQ.Socket socket = context.createSocket(SocketType.REP);
-            socket.bind("tcp://*:5555");
 
-            while (!Thread.currentThread().isInterrupted()) {
-                // Block until a message is received
-                byte[] reply = socket.recv(0);
+	private static final String USAGE_TOPIC = "USAGE";
+	private static final String TEMPERATURE_TOPIC = "TEMPERATURE";
 
-                // Print the message
-                System.out.println(
-                    "Received: [" + new String(reply, ZMQ.CHARSET) + "]"
-                );
+	public static void main(String[] args) {
+		try (ZContext context = new ZContext()) {
 
-                // Send a response
-                String response = "Hello, world!";
-                socket.send(response.getBytes(ZMQ.CHARSET), 0);
-            }
-        }
-    }
\ No newline at end of file
+			ZMQ.Socket usageSub = context.createSocket(SocketType.SUB);
+			usageSub.connect("tcp://*:5555");
+			usageSub.subscribe(USAGE_TOPIC.getBytes());
+
+			ZMQ.Socket temperatureSub = context.createSocket(SocketType.SUB);
+			temperatureSub.connect("tcp://*:5556");
+			temperatureSub.subscribe(TEMPERATURE_TOPIC.getBytes());
+
+			while (true) {
+				String usageData = usageSub.recvStr();
+				String temperatureData = temperatureSub.recvStr();
+				System.out.println(usageData);
+				System.out.println(temperatureData);
+			}
+		}
+	}
+}

sensors/temperature/Dockerfile

@@ -2,4 +2,5 @@ FROM python:3.9.19-alpine3.20
 COPY . /app
 WORKDIR /app
 RUN pip install -r requirements.txt
-CMD ["python", "TemperatureSensor.py"]
\ No newline at end of file
+EXPOSE 5556/tcp
+CMD ["python", "TemperatureSensor.py"]

sensors/usage/Dockerfile

@@ -2,4 +2,5 @@ FROM python:3.9.19-alpine3.20
 COPY . /app
 WORKDIR /app
 RUN pip install -r requirements.txt
-CMD ["python", "UsageSensor.py"]
\ No newline at end of file
+EXPOSE 5555/tcp
+CMD ["python", "UsageSensor.py"]

sensors/usage/UsageSensor.py

@@ -15,4 +15,4 @@ while True:
     data = randrange(100)
     socket.send_string("%s %d" % (TOPIC, data))
     logging.info("Usage sensor send %d" % data)
-    time.sleep(1)
\ No newline at end of file
+    time.sleep(1)