Playframework application + prometheus + grafana

This is just an example of how to monitor a playframework application using:

prometheus client
prometheus
grafana

Prerequisites

To run everything you just need docker.

How to starting everything?

Before running this command be aware that the docker files are quite heavy, so this could take a while

docker-compose up -d

....and everything should be up and running. Something similar to this image

Which means that we have now 4 running containers:

Grafana
CAdvisor
Our play application
Prometheus

The play application

The play application is available at http://localhost:9000/.

The general idea is that the application has a count metric for a particular url

val requests = Counter.build()
  .name("play_requests_total")
  .help("Total requests.")
  .register()

which gets increased each time a user navigates to /

@Singleton
class HomeController @Inject()(visitsCounter: IndexAccessCounter) extends Controller {

  def index = Action {
    visitsCounter.requests.inc()
    Ok(views.html.index("Your new application is ready."))
  }

}

Just in case, don't forget to add the following script to your build.sbt

javaOptions in Universal ++= Seq(
  "-Dpidfile.path=/dev/null"
)

This is a workaroung as the application inside the container is no able to restart because the play app always has the same PID.

Prometheus targets

In order to verify that prometheus was able to connect to out application you can check http://localhost:9090/targets

Theoretically you should have:

a target for our play application
a target for prometheus itself

Before testing the integration between prometheus and grafana you can verify your metrics by going to http://localhost:9090/graph.

You should be able to get something like this

Grafana

The Dashboard is now available at http://localhost:3000 using the following credentials

username: admin
password: admin

The password is stored in the config.monitoring env file.

Once logged in you need to:

Create a data source

Now we need to create the Prometheus Datasource in order to connect Grafana to Prometheus

Go to Grafana Menu at the top left corner (looks like a fireball)
Go to Data Sources
Enter the following data

Import the Dashboard

Import the file Grafana_Dashboard.json

Result

Your resulting Dashboard should be similar to this

Don't forget to go to http://localhost:9000/ and check how your dashboards changes.

malaman / play-prometheus