# Push metrics to Prometheus

This how-to guide shows you how to push metrics from your application using the Prometheus Pushgateway.
This is typically used in Nais jobs, which by it's nature often is short-lived and cannot effectively be scraped by Prometheus.

Prometheus has further explanations and examples [here](https://prometheus.io/docs/instrumenting/pushing/)

## Add pushgateway and accessPolicy to your manifest

> **.nais/naisjob.yaml**
> ```yaml
> apiVersion: nais.io/v1
> kind: Naisjob
> metadata:
>   name: <MY-JOB>
>   namespace: <MY-TEAM>
> spec:
>   image: {{image}}
>   schedule: "*/1 * * * *"
>   env:
>     - name: PUSH_GATEWAY_ADDRESS
>       value: prometheus-pushgateway.nais-system:9091
>   accessPolicy:
>     outbound:
>       rules:
>         - application: prometheus-pushgateway
>           namespace: nais-system
> ```

## Send metrics to your application

```java
package io.prometheus.client.it.pushgateway;

import io.prometheus.client.CollectorRegistry;
import io.prometheus.client.Gauge;
import io.prometheus.client.exporter.BasicAuthHttpConnectionFactory;
import io.prometheus.client.exporter.PushGateway;

public class ExampleBatchJob {
    public static void main(String[] args) throws Exception {
        String jobName = "my_batch_job";
        String pushGatewayAddress = System.getenv("PUSH_GATEWAY_ADDRESS");

        CollectorRegistry registry = new CollectorRegistry();
        Gauge duration = Gauge.build()
                .name("my_batch_job_duration_seconds")
                .help("Duration of my batch job in seconds.")
                .register(registry);
        Gauge.Timer durationTimer = duration.startTimer();
        try {
            Gauge lastSuccess = Gauge.build()
                    .name("my_batch_job_last_success")
                    .help("Last time my batch job succeeded, in unixtime.")
                    .register(registry);
            lastSuccess.setToCurrentTime();
        } finally {
            durationTimer.setDuration();
            PushGateway pg = new PushGateway(pushGatewayAddress);
            pg.pushAdd(registry, jobName);
        }
    }
}
```