io.micronaut.discovery.registration.AutoRegistration Maven / Gradle / Ivy
/*
* Copyright 2017-2020 original authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.micronaut.discovery.registration;
import io.micronaut.context.event.ApplicationEventListener;
import io.micronaut.discovery.ServiceInstance;
import io.micronaut.discovery.event.AbstractServiceInstanceEvent;
import io.micronaut.discovery.event.ServiceStoppedEvent;
import io.micronaut.discovery.event.ServiceReadyEvent;
import io.micronaut.discovery.exceptions.DiscoveryException;
import io.micronaut.health.HealthStatus;
import io.micronaut.health.HeartbeatEvent;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.regex.Pattern;
/**
* A base class for classes that automatically register the server with discovery services.
*
* @author Graeme Rocher
* @since 1.0
*/
public abstract class AutoRegistration implements ApplicationEventListener {
protected static final Logger LOG = LoggerFactory.getLogger(AutoRegistration.class);
private static final Pattern APPLICATION_NAME_PATTERN = Pattern.compile("^[a-zA-Z][\\w\\d-]*[a-zA-Z\\d]$");
protected final AtomicBoolean registered = new AtomicBoolean(false);
private final RegistrationConfiguration registrationConfiguration;
/**
* Initialize given configurations.
*
* @param registrationConfiguration Common configurations for registration
*/
protected AutoRegistration(RegistrationConfiguration registrationConfiguration) {
this.registrationConfiguration = registrationConfiguration;
}
@Override
public void onApplicationEvent(AbstractServiceInstanceEvent event) {
if (registrationConfiguration.isEnabled()) {
if (event instanceof ServiceReadyEvent) {
register(event.getSource());
} else if (event instanceof ServiceStoppedEvent) {
if (registrationConfiguration.isDeregister()) {
deregister(event.getSource());
}
} else if (event instanceof HeartbeatEvent) {
HeartbeatEvent heartbeatEvent = (HeartbeatEvent) event;
pulsate(event.getSource(), heartbeatEvent.getStatus());
}
}
}
/**
* This method will be invoked each time a {@link HeartbeatEvent} occurs allowing the implementation to perform any necessary callbacks to the service discovery server.
*
* @param instance The instance
* @param status The {@link HealthStatus}
*/
protected abstract void pulsate(ServiceInstance instance, HealthStatus status);
/**
* Deregister the {@link ServiceInstance} from service discovery services.
*
* @param instance The {@link ServiceInstance}
*/
protected abstract void deregister(ServiceInstance instance);
/**
* Register the {@link ServiceInstance} with discovery services.
*
* @param instance The {@link ServiceInstance}
*/
protected abstract void register(ServiceInstance instance);
/**
* Validate the given application name.
*
* @param name The application name
*/
protected void validateApplicationName(String name) {
String typeDescription = "Application name";
validateName(name, typeDescription);
}
/**
* Validate the given application name.
*
* @param name The application name
* @param typeDescription The detailed information about name
*/
protected void validateName(String name, String typeDescription) {
if (!APPLICATION_NAME_PATTERN.matcher(name).matches()) {
throw new DiscoveryException(typeDescription + " [" + name + "] must start with a letter, end with a letter or digit and contain only letters, digits or hyphens. Example: foo-bar");
}
}
}