Use case: HTTP POST to remote server¶

In this section, we will explain how to send KPIs to a remote HTTP server using POST requests.

For the purpose of this use case, let’s launch a python HTTP server that is able to process POST request on a linux host with IP address a.b.c.d.

Create a file named dummy-server.py with this content:

#!/usr/bin/env python
from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer

class HTTPPostHandler(BaseHTTPRequestHandler):
    def do_POST(self):
        content_length = int(self.headers['Content-Length'])
        post_data = self.rfile.read(content_length)
        print(post_data)

        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        self.wfile.write("<html><body><h1>POST!</h1></body></html>")

def run():
    httpd = HTTPServer(('', 8000), HTTPPostHandler)
    print('Starting httpd...')
    httpd.serve_forever()

if __name__ == "__main__":
    run()

Start the server:
```
# python dummy-server.py
```

On a freshly booted system, start monitoring:

# monitoring.sh start
Starting Monitoring...
Monitoring successfully started

Check that the monitoring has been properly started

# monitoring.sh status
* kpid.service - KPI Daemon
   Loaded: loaded (/lib/systemd/system/kpid.service; disabled; vendor preset: enabled)
   Active: active (running) since Tue 2020-06-16 09:31:53 UTC; 3s ago
 Main PID: 3526 (kpid)
    Tasks: 1 (limit: 1088)
   CGroup: /system.slice/kpid.service
           `-3526 /usr/bin/python3 /usr/bin/kpid

* netopeer2-server.service - NETCONF Server
   Loaded: loaded (/lib/systemd/system/netopeer2-server.service; enabled; vendor preset: enabled)
   Active: active (running) since Mon 2020-06-16 09:31:52 UTC; 4s ago
 Main PID: 1067 (netopeer2-serve)
    Tasks: 7 (limit: 1088)
   CGroup: /system.slice/netopeer2-server.service
           `-1067 /usr/bin/netopeer2-server -U -g netconf -m 660

Do an HTTP post of the fast path cpu usage in json format every 10 seconds to http://a.b.c.d:8000/write. Change a.b.c.d to match the remote host’s address:

# while true; do
    kpi-get fp-cpu-usage -o http-json:host=a.b.c.d:port=8000:path=write
    sleep 10
  done

On the web server, you should see POST requests every 10 seconds or so:

{"sixwind-router:monitoring": {"fp:fp-cpu-usage": [{"cpu": "cpu1", "busy": 0}, {"cpu": "cpu2", "busy": 0}, {"cpu": "cpu3", "busy": 0}]}}
127.0.0.1 - - [13/Dec/2017 16:04:37] "POST /write HTTP/1.1" 200 -
{"sixwind-router:monitoring": {"fp:fp-cpu-usage": [{"cpu": "cpu1", "busy": 0}, {"cpu": "cpu2", "busy": 0}, {"cpu": "cpu3", "busy": 0}]}}
127.0.0.1 - - [13/Dec/2017 16:04:48] "POST /write HTTP/1.1" 200 -
{"sixwind-router:monitoring": {"fp:fp-cpu-usage": [{"cpu": "cpu1", "busy": 0}, {"cpu": "cpu2", "busy": 0}, {"cpu": "cpu3", "busy": 0}]}}
127.0.0.1 - - [13/Dec/2017 16:04:59] "POST /write HTTP/1.1" 200 -
{"sixwind-router:monitoring": {"fp:fp-cpu-usage": [{"cpu": "cpu1", "busy": 0}, {"cpu": "cpu2", "busy": 0}, {"cpu": "cpu3", "busy": 0}]}}
127.0.0.1 - - [13/Dec/2017 16:05:09] "POST /write HTTP/1.1" 200 -