update service discovery example

tutorials/dms/simple_rest.json

@@ -1,13 +1,20 @@
 {
-  "name":"simplerest",
-  "tags":["bdp","nothing","aalto"],
-   "port": 3000,
-   "address":"192.168.2.14",
-   "check": {
-       "id": "checksimplerest",
-       "name": "Simple Status",
-       "args": ["curl","http://localhost:3000/health"],
-       "interval": "20s",
-       "timeout": "10s"
-   }
-}
+  "name": "simplerest",
+  "tags": [
+    "bdp",
+    "nothing",
+    "aalto"
+  ],
+  "port": 3000,
+  "address": "192.168.8.106",
+  "check": {
+    "id": "checksimplerest",
+    "name": "Simple Status",
+    "args": [
+      "curl",
+      "http://192.168.8.106:3000/health"
+    ],
+    "interval": "20s",
+    "timeout": "10s"
+  }
+}

tutorials/servicediscovery/README.md

@@ -6,20 +6,23 @@ We use [consul](https://www.consul.io/) for service discovery.
 >You can also use ZooKeeper and etcd to study. But then you need to adapt the code for them
 
 ## Practices
+
 > change the code to fix it into your setting, especially, we have some specific paths/urls in the code
 
 ### Running consul
+
 * Make sure that you have consul installed in your machine.
 * using consul-server.sh to run a consul server for testing
 ```
-$sh consul-server.sh aaltocs aaltosea /tmp/consul 0.0.0.0
+$bash consul-server.sh aaltocs aaltosea /tmp/consul 0.0.0.0
 ```
 Meaning that we run a consul server with:
 * -datacenter=aaltocs: to indicate the data center
 * -node=aaltosea: to indicate the name of the agent
 * -data-dir=/tmp/consul: to indicate the place where the data is stored
 * -bind=0.0.0.0: to indicate the network interface for the internal cluster communication
-You should see consul running
+
+You should see consul running: for example check http://localhost:8500/ 
 
 ### Run some services
 
@@ -47,5 +50,11 @@ In principle, services will publish their information into consul. We just make
   ```
   the simple_rest.json can be obtained by calling simple_rest **curl -X GET http://localhost:3000/self**.
 
-* check consul service using http://localhost:8500/ui to see if services are alive or not
+* check your consul service, e.g., using http://localhost:8500/ui to see if services are alive or not
+
+You should see consul running: for example check http://localhost:8500/
+![Consul UI: services are up](consului.png)
+
 * start and stop simple_rest.js and mongodb container and then go to the consul UI to see if the services are alive or not
+
+![Consul UI: simpleret is down](consuluidown.png)

tutorials/servicediscovery/consul-server.sh

@@ -1,3 +1,3 @@
 #!/bin/bash
-#example: -datacenter=aaltocs -data-dir=/tmp/consul -bind=0.0.0.0 -
+#example: -datacenter=aaltocs -node=cse4640 -data-dir=/tmp/consul -bind=0.0.0.0 -
 /opt/consul/consul agent -enable-script-checks -datacenter=$1 -node $2 -data-dir=$3 -bind=$4 -server -dev

tutorials/servicediscovery/mongocheck.py

@@ -1,10 +1,16 @@
 #!/usr/bin/python3
+import argparse
 from pymongo import MongoClient
 import sys
-## Just hardcode
-client = MongoClient(sys.argv[1])
-result=client.db_name.command('ping')
-if result is None:
-    print("Problem")
-    sys.exit(2)
-sys.exit (0)
+
+if __name__ == "__main__":    
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--service_url', default='mongodb://localhost:27017',help='URL of the server')
+    args = parser.parse_args()
+    url =args.service_url
+    if url:
+        client = MongoClient(url)
+        result=client.db_name.command('ping')
+        if result is None:
+            print("Problem")
+            sys.exit(2)

tutorials/servicediscovery/mongoservice.json

@@ -2,11 +2,11 @@
   "name":"mongodb",
   "tags":["bdp","sensordata","aalto"],
    "port": 27017,
-   "address":"192.168.0.14",
+   "address":"192.168.8.106",
    "check": {
        "id": "checkmongdo",
        "name": "Mongodb Status",
-       "args": ["/home/truong/myprojects/mygit/cs-e4640/tutorials/servicediscovery/mongocheck.py","mongodb://192.168.0.14:27017"],
+       "args": ["/home/truong/myprojects/mygit/bigdataplatforms/tutorials/servicediscovery/mongocheck.py","--service_url", "mongodb://192.168.8.106:27017"],
        "interval": "20s",
        "timeout": "5s"
    }