This is the basic ITU_MiniTwit application (Python 3 and SQLite) with added support for monitoring with Prometheus and Grafana as a Dashboard.

The application is Dockerized. To build the application and a client which simulates users clicking around the front page you have to:

• Build the application:

$ docker build -f docker/minitwit/Dockerfile -t <youruser>/webserver .

• Build the test client:

$ docker build -f docker/minitwit_client/Dockerfile -t <youruser>/minitwitclient .

• Start the application:

$ docker-compose up

Alternatively, you can build and run the application in one step:

$ docker-compose up --build

To stop the application again run:

$ docker-compose down -v

After starting the entire application, you can reach:

• ITU-MiniTwit at http://localhost:5000
• ITU-MiniTwit metrics for this node at http://localhost:5000/metrics
• The Prometheus web-client at http://localhost:9090
• Grafana at http://localhost:3000 (default login and password: admin)

Starting Grafana and Instantiating a Dashboard

Navigate your browser to http://localhost:3000 and login with the default credentials admin/admin. Remember later to change the password for your projects!

Now, do the following:

• Add data source

• Set the Name to a name that you deem suitable
• Under Config choose the Type Prometheus
• Under Http settings set the Url to http://prometheus:9090
• Finally, click Add

Now, Create your first dashboard:

Add a SingleStat click on the Panel Title and choose Edit.

Keep Data Source as default and add the PromQL query minitwit_http_responses_total to the field below.

Now, play and customize the dashboard a bit to your liking and add some other metrics.

Installing new Panels

In case you need another panel type for example a gauge for the CPU load and in case you are running Grafana via Docker follow the steps below.

• Navigate to https://grafana.com/plugins?type=panel
• Choose a panel of your liking, e.g., https://grafana.com/plugins/briangann-gauge-panel/installation
• Copy the installation command, which has to be run on the Grafana server (machine)

$ docker exec -it itu-minitwit-monitoring_grafana_1 /bin/bash
root@9c17c8757ffb:/# grafana-cli plugins install briangann-gauge-panel
installing briangann-gauge-panel @ 0.0.6
from url: https://grafana.com/api/plugins/briangann-gauge-panel/versions/0.0.6/download
into: /var/lib/grafana/plugins

✔ Installed briangann-gauge-panel successfully

Restart grafana after installing plugins . <service grafana-server restart>

root@9c17c8757ffb:/# exit
exit
$ docker restart itu-minitwit-monitoring_grafana_1
itu-minitwit-monitoring_grafana_1

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This minitwit.py application was adapted to be monitored with Prometheus with the help of this blog post.