CODEWITHSUNDEEP
javaspring-bootprometheus
Daniela
Daniela

Reputation: 71

Use prometheus metrics servlet in management port of springboot

I'm using prometheus metric servlet to expose my metrics, with the java client api prometheus supply.

I registered the servlet the same way of registering any servelt, see below:

 @Bean
public ServletRegistrationBean registerPrometheusExporterServlet(CollectorRegistry metricRegistry) {
    return new ServletRegistrationBean(new MetricsServlet(metricRegistry), "/metrics");
}

However, I would like to add this servlet to the management port or if it is possible that the prometheus version will replace the default /metrics service of springboot. Can something like this can be done? and how?

Thanks, Daniela

Upvotes: 3

Views: 7655

Answers (1)

riccardo.cardin
riccardo.cardin

Reputation: 8353

I don't know if you were able to integrate Spring Boot with Prometheus, but now there is a dedicated connector in the official Prometheus client-java project.

The Github page of the project is the following: simpleclient_spring_boot

You can use it adding the following dependency to you pom.xml

<dependency>
    <groupId>io.prometheus</groupId>
    <artifactId>simpleclient_spring_boot</artifactId>
    <version>0.0.17</version>
</dependency>

To use it, add a Spring Boot configuration to your project, like the following.

@Configuration
public class MetricsConfiguration {

    @Bean
    public ServletRegistrationBean servletRegistrationBean() {
        DefaultExports.initialize();
        return new ServletRegistrationBean(new MetricsServlet(), "/prometheus");
    }

    @Bean
    public SpringBootMetricsCollector springBootMetricsCollector(Collection<PublicMetrics> publicMetrics) {
        SpringBootMetricsCollector springBootMetricsCollector = new SpringBootMetricsCollector(
            publicMetrics);
        springBootMetricsCollector.register();
        return springBootMetricsCollector;
    }
}

Now on, the metrics exposed by Spring Boot Actuator will be available as Prometheus Counters and Gauges.

The information are published to the path /prometheus of your application. Then you have to instruct Prometheus to consume this information, with a configuration like the following.

# my global config
global:
  scrape_interval:     15s # By default, scrape targets every 15 seconds.
  evaluation_interval: 15s # By default, scrape targets every 15 seconds.

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
- job_name: 'your-application-name'

  scrape_interval: 5s

  metrics_path: '/prometheus'

  static_configs:
    - targets: ['localhost:8080']

If you point your browser to /metrics you will continue to see information in Spring Boot format. But, pointing the browser to http://localhost:9090/graph you will query into such information directly into Prometheus query browser.

Try to have a look also to this Github pull-request.

UPDATE
In the next release of the simpleclient_spring_boot, 0.0.18, it will be sufficient to add the annotation @EnablePrometheusEndpoint to the configuration class of Spring Boot to automagically configure the Prometheus adapter (have a look to this test)!

Hope it helps.

Upvotes: 6

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