Metric in micrometer in URI template . Some path variable needs to be replaced from URL - spring-micrometer

Question

I want to collect metrics for particular REST API
Suppose I have a URL like /company/{companyName}/person/{id}
Is it possible to collect metrics across
/company/test/person/{id}
/compaby/test2/person/{id}

Answer 1

There's no out-of-the-box support for it but you can provide your own WebMvcTagsProvider to implement it via a Spring bean.
Note that it could lead to tag explosion and end up with OOM if there's any possibility to companyName path variable explosion by a mistake or attack.

Answer 2

In case you are using Spring and RestTemplate for http call, you can register MetricsClientHttpRequestInterceptor with your RestTemplate .
import javax.annotation.PostConstruct;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.actuate.autoconfigure.metrics.MetricsAutoConfiguration;
import org.springframework.boot.actuate.metrics.web.client.MetricsRestTemplateCustomizer;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;
import org.springframework.web.client.RestTemplate;
#Component
#AutoConfigureAfter({MetricsAutoConfiguration.class})
public class RestClientMetricConfiguration {
private final ApplicationContext applicationContext;
#Autowired
public RestClientMetricConfiguration(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
#PostConstruct
public void init() {
MetricsRestTemplateCustomizer restTemplateCustomizer =
applicationContext.getBean(MetricsRestTemplateCustomizer.class);
applicationContext.getBeansOfType(RestTemplate.class).values().forEach(restTemplateCustomizer::customize);
}
}
And use Below method provided by spring RestTemplate to make http call.
public <T> ResponseEntity<T> exchange(String url, HttpMethod method, #Nullable HttpEntity<?> requestEntity, ParameterizedTypeReference<T> responseType, Map<String, ?> uriVariables) throws RestClientException {
Type type = responseType.getType();
RequestCallback requestCallback = this.httpEntityCallback(requestEntity, type);
ResponseExtractor<ResponseEntity<T>> responseExtractor = this.responseEntityExtractor(type);
return (ResponseEntity)nonNull(this.execute(url, method, requestCallback, responseExtractor, uriVariables));
}