fix nats monitoring port

compose/gen-docker.js

@@ -27,6 +27,7 @@ const generateAgent = (agentNum) => {
   const connectionManagerPort = startPort++;
   const attestationManagerPort = startPort++;
   const proofManagerPort = startPort++;
+  const natsMonitoringPort = startPort++;
 
   const envContent = `LEDGERS=IDUNION
 IDUNION_KEY=${IDUNION_KEY}
@@ -179,7 +180,7 @@ PROOF_SERVICE_HOST=pm-${genericName}
     image: 'nats:latest'
     ports:
       - '4222' #Nats server port
-      - '8222:8222' #Nats server Monitoring port
+      - '${natsMonitoringPort}:8222' #Nats server Monitoring port
     volumes:
       - ./data/${genericName}/nats/:/data/
 `;
@@ -235,3 +236,4 @@ ${dockerServices.join('\n')}
 `;
 
 fs.writeFileSync(`./docker-compose-gen.yml`, dockerContent);
+