This project contains a Spring Boot Starter that registers HTTP endpoints on a Spring Cloud Eureka server to support Prometheus's discovery mechanism for Consul (<consul_sd_config>)
This adapter does not support everything of Consul's HTTP API but only those endpoints and attributes that are required for Prometheus' service discovery mechanism.
This starter adds the following HTTP endpoints:
/v1/agent/self
Returns the name of the datacenter in use (Consul API: https://www.consul.io/api/agent.html#read-configuration). In Eureka, this can be set using thearchaius.deployment.datacenter
configuration property./v1/catalog/services
Returns the names of the deployed applications (Consul API: https://www.consul.io/api/catalog.html#list-services). No service tags service will be returned as Eureka does not support this concept./v1/catalog/service/{service}
Returns all available details for the particular application (instances, host names, ports, meta data, service tags). No service tags service will be returned as Eureka does not support this concept.
Consul HTTP API offers long-polling on some of its endpoints. Prometheus' client uses this functionality to get
notified about changes in the registry (i.e. service de-/registrations). Prometheus adds the wait
parameter
(e.g. https://service-registry/v1/catalog/service/MY-SERVICE?wait=30000ms ), which causes the response
to be delayed by specified time passed or returns immediately if the service itself changes within this time range.
This behaviour has the benefit, that services changes are detected at once whithout have to wait the whole polling interval.
Prometheus opens one long-polling request for each service. In order not to block one thread for each call, this adapter
uses the async capabilities of Spring MVC. The default timeout for async requests is by default lower than 30 seconds
and can cause AsyncRequestTimeoutExceptions
. To prevent this you need to set spring.mvc.async.request-timeout
to
at least 35000 (35 seconds).
Simply add this dependency the your Spring Cloud Eureka Server (https://github.com/spring-cloud-samples/eureka):
<dependency>
<groupId>at.twinformatics</groupId>
<artifactId>eureka-consul-adapter</artifactId>
<version>${eureka-consul-adapter.version}<version>
</dependency>
dependencies {
compile 'at.twinformatics:eureka-consul-adapter:${eureka-consul-adapter.version}'
}
- Java 1.8+
- Spring Boot 2.0
- Spring Cloud Finchley
- Spring Boot 1.5
- Spring Cloud Edgware