ServiceInstance.java
/*
* 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
*
* https://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;
import io.micronaut.core.convert.value.ConvertibleValues;
import io.micronaut.core.util.StringUtils;
import io.micronaut.health.HealthStatus;
import io.micronaut.http.HttpHeaders;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import java.util.Optional;
/**
* <p>Represents a remote service discovered by the underlying discovery implementation.</p>
*
* @author Graeme Rocher
* @since 1.0
*/
public interface ServiceInstance {
/**
* Constant to represent the group of the service contained with {@link #getMetadata()}.
*/
String GROUP = "group";
/**
* Constant to represent the zone of the service contained with {@link #getMetadata()}.
*/
String ZONE = "zone";
/**
* Constant to represent the region of the service contained with {@link #getMetadata()}.
*/
String REGION = "region";
/**
* @return The identifier of the service used for purposes of service discovery
*/
String getId();
/**
* @return The service URI
*/
URI getURI();
/**
* @return The {@link HealthStatus} of the instance
*/
default HealthStatus getHealthStatus() {
return HealthStatus.UP;
}
/**
* @return The ID of the instance
*/
default Optional<String> getInstanceId() {
return Optional.empty();
}
/**
* Returns the availability zone to use. A zone is, for example, the AWS availability zone.
*
* @return The zone to use
*/
default Optional<String> getZone() {
return getMetadata().get(ZONE, String.class);
}
/**
* Returns the region to use. A region is, for example, the AWS region
*
* @return The region
*/
default Optional<String> getRegion() {
return getMetadata().get(REGION, String.class);
}
/**
* Returns the application group. For example, the AWS auto-scaling group.
*
* @return The group to use
*/
default Optional<String> getGroup() {
return getMetadata().get(GROUP, String.class);
}
/**
* @return The service metadata
*/
default ConvertibleValues<String> getMetadata() {
return ConvertibleValues.empty();
}
/**
* @return The service host
*/
default String getHost() {
return getURI().getHost();
}
/**
* @return Is the service instance available over a secure connection
*/
default boolean isSecure() {
String scheme = getURI().getScheme();
return scheme != null && scheme.equalsIgnoreCase("https");
}
/**
* @return The service port
*/
default int getPort() {
return getURI().getPort();
}
/**
* Resolve a URI relative to this service instance.
*
* @param relativeURI The relative URI
* @return The relative URI
*/
default URI resolve(URI relativeURI) {
URI thisUri = getURI();
// if the URI features credentials strip this out
if (StringUtils.isNotEmpty(thisUri.getUserInfo())) {
try {
thisUri = new URI(thisUri.getScheme(), null, thisUri.getHost(), thisUri.getPort(), thisUri.getPath(), thisUri.getQuery(), thisUri.getFragment());
} catch (URISyntaxException e) {
throw new IllegalStateException("ServiceInstance URI is invalid: " + e.getMessage(), e);
}
}
String rawQuery = thisUri.getRawQuery();
if (StringUtils.isNotEmpty(rawQuery)) {
return thisUri.resolve(relativeURI + "?" + rawQuery);
} else {
return thisUri.resolve(relativeURI);
}
}
/**
* Construct a new {@link ServiceInstance} for the given ID and URL.
*
* @param id The ID
* @param url The URL
* @return The instance
*/
static ServiceInstance of(String id, URL url) {
try {
URI uri = url.toURI();
return of(id, uri);
} catch (URISyntaxException e) {
throw new IllegalArgumentException("Invalid URI argument: " + url);
}
}
/**
* Construct a new {@link ServiceInstance} for the given ID and URL.
*
* @param id The ID
* @param uri The URI
* @return The instance
*/
static ServiceInstance of(String id, URI uri) {
return new ServiceInstance() {
@Override
public String getId() {
return id;
}
@Override
public URI getURI() {
return uri;
}
@Override
public ConvertibleValues<String> getMetadata() {
String userInfo = uri.getUserInfo();
if (userInfo == null) {
return ServiceInstance.super.getMetadata();
} else {
var metadata = new HashMap<String, String>(1);
metadata.put(HttpHeaders.AUTHORIZATION_INFO, userInfo);
return ConvertibleValues.of(metadata);
}
}
};
}
/**
* Construct a new {@link ServiceInstance} for the given ID, host and port using the HTTP scheme.
*
* @param id The ID
* @param host The host
* @param port The port
* @return The instance
*/
static ServiceInstance of(String id, String host, int port) {
return new ServiceInstance() {
@Override
public String getId() {
return id;
}
@Override
public URI getURI() {
return URI.create("http://" + host + ":" + port);
}
};
}
/**
* A builder to builder a {@link ServiceInstance}.
*
* @param id The id
* @param uri The URI
* @return The builder
*/
static Builder builder(String id, URI uri) {
return new DefaultServiceInstance(id, uri);
}
/**
* A builder for building {@link ServiceInstance} references.
*/
interface Builder {
/**
* Sets the instance id.
*
* @param id The instance id
* @return This builder
*/
Builder instanceId(String id);
/**
* Sets the zone.
*
* @param zone The zone
* @return This builder
*/
Builder zone(String zone);
/**
* Sets the region.
*
* @param region The region
* @return This builder
*/
Builder region(String region);
/**
* Sets the application group.
*
* @param group The group
* @return This builder
*/
Builder group(String group);
/**
* Sets the application status.
*
* @param status The status
* @return This builder
*/
Builder status(HealthStatus status);
/**
* Sets the application metadata.
*
* @param metadata The metadata
* @return This builder
*/
Builder metadata(Map<String, String> metadata);
/**
* @return The instance
*/
ServiceInstance build();
}
}