/*
* Copyright 2012 Netflix, Inc.
*
* 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 com.netflix.eureka.resources;
import javax.ws.rs.Consumes;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import com.netflix.appinfo.AmazonInfo;
import com.netflix.appinfo.DataCenterInfo;
import com.netflix.appinfo.EurekaAccept;
import com.netflix.appinfo.InstanceInfo;
import com.netflix.appinfo.UniqueIdentifier;
import com.netflix.eureka.EurekaServerConfig;
import com.netflix.eureka.registry.PeerAwareInstanceRegistry;
import com.netflix.eureka.Version;
import com.netflix.eureka.cluster.PeerEurekaNode;
import com.netflix.eureka.registry.ResponseCache;
import com.netflix.eureka.registry.Key.KeyType;
import com.netflix.eureka.registry.Key;
import com.netflix.eureka.util.EurekaMonitors;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* A <em>jersey</em> resource that handles request related to a particular
* {@link com.netflix.discovery.shared.Application}.
*
* @author Karthik Ranganathan, Greg Kim
*
*/
@Produces({"application/xml", "application/json"})
public class ApplicationResource {
private static final Logger logger = LoggerFactory.getLogger(ApplicationResource.class);
private final String appName;
private final EurekaServerConfig serverConfig;
private final PeerAwareInstanceRegistry registry;
private final ResponseCache responseCache;
ApplicationResource(String appName,
EurekaServerConfig serverConfig,
PeerAwareInstanceRegistry registry) {
this.appName = appName.toUpperCase();
this.serverConfig = serverConfig;
this.registry = registry;
this.responseCache = registry.getResponseCache();
}
public String getAppName() {
return appName;
}
/**
* Gets information about a particular {@link com.netflix.discovery.shared.Application}.
*
* @param version
* the version of the request.
* @param acceptHeader
* the accept header of the request to indicate whether to serve
* JSON or XML data.
* @return the response containing information about a particular
* application.
*/
@GET
public Response getApplication(@PathParam("version") String version,
@HeaderParam("Accept") final String acceptHeader,
@HeaderParam(EurekaAccept.HTTP_X_EUREKA_ACCEPT) String eurekaAccept) {
if (!registry.shouldAllowAccess(false)) {
return Response.status(Status.FORBIDDEN).build();
}
EurekaMonitors.GET_APPLICATION.increment();
CurrentRequestVersion.set(Version.toEnum(version));
KeyType keyType = Key.KeyType.JSON;
if (acceptHeader == null || !acceptHeader.contains("json")) {
keyType = Key.KeyType.XML;
}
Key cacheKey = new Key(
Key.EntityType.Application,
appName,
keyType,
CurrentRequestVersion.get(),
EurekaAccept.fromString(eurekaAccept)
);
String payLoad = responseCache.get(cacheKey);
if (payLoad != null) {
logger.debug("Found: {}", appName);
return Response.ok(payLoad).build();
} else {
logger.debug("Not Found: {}", appName);
return Response.status(Status.NOT_FOUND).build();
}
}
/**
* Gets information about a particular instance of an application.
*
* @param id
* the unique identifier of the instance.
* @return information about a particular instance.
*/
@Path("{id}")
public InstanceResource getInstanceInfo(@PathParam("id") String id) {
return new InstanceResource(this, id, serverConfig, registry);
}
/**
* Registers information about a particular instance for an
* {@link com.netflix.discovery.shared.Application}.
*
* @param info
* {@link InstanceInfo} information of the instance.
* @param isReplication
* a header parameter containing information whether this is
* replicated from other nodes.
*/
@POST
@Consumes({"application/json", "application/xml"})
public Response addInstance(InstanceInfo info,
@HeaderParam(PeerEurekaNode.HEADER_REPLICATION) String isReplication) {
logger.debug("Registering instance {} (replication={})", info.getId(), isReplication);
// validate that the instanceinfo contains all the necessary required fields
if (isBlank(info.getId())) {
return Response.status(400).entity("Missing instanceId").build();
} else if (isBlank(info.getHostName())) {
return Response.status(400).entity("Missing hostname").build();
} else if (isBlank(info.getAppName())) {
return Response.status(400).entity("Missing appName").build();
} else if (!appName.equals(info.getAppName())) {
return Response.status(400).entity("Mismatched appName, expecting " + appName + " but was " + info.getAppName()).build();
} else if (info.getDataCenterInfo() == null) {
return Response.status(400).entity("Missing dataCenterInfo").build();
} else if (info.getDataCenterInfo().getName() == null) {
return Response.status(400).entity("Missing dataCenterInfo Name").build();
}
// handle cases where clients may be registering with bad DataCenterInfo with missing data
DataCenterInfo dataCenterInfo = info.getDataCenterInfo();
if (dataCenterInfo instanceof UniqueIdentifier) {
String dataCenterInfoId = ((UniqueIdentifier) dataCenterInfo).getId();
if (isBlank(dataCenterInfoId)) {
boolean experimental = "true".equalsIgnoreCase(serverConfig.getExperimental("registration.validation.dataCenterInfoId"));
if (experimental) {
String entity = "DataCenterInfo of type " + dataCenterInfo.getClass() + " must contain a valid id";
return Response.status(400).entity(entity).build();
} else if (dataCenterInfo instanceof AmazonInfo) {
AmazonInfo amazonInfo = (AmazonInfo) dataCenterInfo;
String effectiveId = amazonInfo.get(AmazonInfo.MetaDataKey.instanceId);
if (effectiveId == null) {
amazonInfo.getMetadata().put(AmazonInfo.MetaDataKey.instanceId.getName(), info.getId());
}
} else {
logger.warn("Registering DataCenterInfo of type {} without an appropriate id", dataCenterInfo.getClass());
}
}
}
registry.register(info, "true".equals(isReplication));
return Response.status(204).build(); // 204 to be backwards compatible
}
/**
* Returns the application name of a particular application.
*
* @return the application name of a particular application.
*/
String getName() {
return appName;
}
private boolean isBlank(String str) {
return str == null || str.isEmpty();
}
}