/*
* 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 java.util.Arrays;
import javax.annotation.Nullable;
import javax.ws.rs.GET;
import javax.ws.rs.HeaderParam;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.QueryParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.Response.Status;
import javax.ws.rs.core.UriInfo;
import com.netflix.eureka.CurrentRequestVersion;
import com.netflix.eureka.EurekaServerConfig;
import com.netflix.eureka.EurekaServerConfigurationManager;
import com.netflix.eureka.PeerAwareInstanceRegistry;
import com.netflix.eureka.Version;
import com.netflix.eureka.resources.ResponseCache.Key;
import com.netflix.eureka.resources.ResponseCache.KeyType;
import com.netflix.eureka.util.EurekaMonitors;
/**
* A <em>jersey</em> resource that handles request related to all
* {@link com.netflix.discovery.shared.Applications}.
*
* @author Karthik Ranganathan, Greg Kim
*
*/
@Path("/{version}/apps")
@Produces({ "application/xml", "application/json" })
public class ApplicationsResource {
private static final String HEADER_ACCEPT = "Accept";
private static final String HEADER_ACCEPT_ENCODING = "Accept-Encoding";
private static final String HEADER_CONTENT_ENCODING = "Content-Encoding";
private static final String HEADER_GZIP_VALUE = "gzip";
private static final String HEADER_JSON_VALUE = "json";
private final EurekaServerConfig eurekaConfig = EurekaServerConfigurationManager
.getInstance().getConfiguration();
/**
* Gets information about a particular {@link com.netflix.discovery.shared.Application}.
*
* @param version
* the version of the request.
* @param appId
* the unique application identifier (which is the name) of the
* application.
* @return information about a particular application.
*/
@Path("{appId}")
public ApplicationResource getApplicationResource(
@PathParam("version") String version,
@PathParam("appId") String appId) {
CurrentRequestVersion.set(Version.toEnum(version));
return new ApplicationResource(appId);
}
/**
* Get information about all {@link com.netflix.discovery.shared.Applications}.
*
* @param version
* the version of the request.
* @param acceptHeader
* the accept header of the request to indicate whether to serve
* JSON or XML data.
*
* @param acceptEncoding
* the accept header of the request to indicate whether to serve
* compressed or uncompressed data.
* @param uriInfo
* the {@link java.net.URI} information of the request made.
* @param regionsStr A comma separated list of remote regions from which the
* instances will also be returned. The applications returned
* from the remote region can be limited to the applications
* returned by {@link EurekaServerConfig#getRemoteRegionAppWhitelist(String)}
* @return response containing information about all {@link com.netflix.discovery.shared.Applications}
* from the {@link com.netflix.eureka.InstanceRegistry}.
*/
@GET
public Response getContainers(@PathParam("version") String version,
@HeaderParam(HEADER_ACCEPT) String acceptHeader,
@HeaderParam(HEADER_ACCEPT_ENCODING) String acceptEncoding,
@Context UriInfo uriInfo, @Nullable @QueryParam("regions") String regionsStr) {
boolean isRemoteRegionRequested = null != regionsStr && !regionsStr.isEmpty();
String[] regions = null;
if (!isRemoteRegionRequested) {
EurekaMonitors.GET_ALL.increment();
} else {
regions = regionsStr.toLowerCase().split(",");
Arrays.sort(regions); // So we don't have different caches for same regions queried in different order.
EurekaMonitors.GET_ALL_WITH_REMOTE_REGIONS.increment();
}
// Check if the server allows the access to the registry. The server can
// restrict access if it is not
// ready to serve traffic depending on various reasons.
if (!PeerAwareInstanceRegistry.getInstance().shouldAllowAccess(isRemoteRegionRequested)) {
return Response.status(Status.FORBIDDEN).build();
}
CurrentRequestVersion.set(Version.toEnum(version));
KeyType keyType = KeyType.JSON;
if (acceptHeader == null || !acceptHeader.contains(HEADER_JSON_VALUE)) {
keyType = KeyType.XML;
}
Key cacheKey = new Key(Key.EntityType.Application, ResponseCache.ALL_APPS, regions, keyType,
CurrentRequestVersion.get());
if (acceptEncoding != null
&& acceptEncoding.contains(HEADER_GZIP_VALUE)) {
return Response.ok(ResponseCache.getInstance().getGZIP(cacheKey))
.header(HEADER_CONTENT_ENCODING, HEADER_GZIP_VALUE).build();
} else {
return Response.ok(ResponseCache.getInstance().get(cacheKey))
.build();
}
}
/**
* Get information about all delta changes in {@link com.netflix.discovery.shared.Applications}.
*
* <p>
* The delta changes represent the registry information change for a period
* as configured by
* {@link EurekaServerConfig#getRetentionTimeInMSInDeltaQueue()}. The
* changes that can happen in a registry include
* <em>Registrations,Cancels,Status Changes and Expirations</em>. Normally
* the changes to the registry are infrequent and hence getting just the
* delta will be much more efficient than getting the complete registry.
* </p>
*
* <p>
* Since the delta information is cached over a period of time, the requests
* may return the same data multiple times within the window configured by
* {@link EurekaServerConfig#getRetentionTimeInMSInDeltaQueue()}.The clients
* are expected to handle this duplicate information.
* <p>
*
* @param version
* the version of the request.
* @param acceptHeader
* the accept header of the request to indicate whether to serve
* JSON or XML data.
*
* @param acceptEncoding
* the accept header of the request to indicate whether to serve
* compressed or uncompressed data.
* @param uriInfo
* the {@link java.net.URI} information of the request made.
* @return response containing the delta information of the
* {@link com.netflix.eureka.InstanceRegistry}.
*/
@Path("delta")
@GET
public Response getContainerDifferential(
@PathParam("version") String version,
@HeaderParam(HEADER_ACCEPT) String acceptHeader,
@HeaderParam(HEADER_ACCEPT_ENCODING) String acceptEncoding,
@Context UriInfo uriInfo, @Nullable @QueryParam("regions") String regionsStr) {
boolean isRemoteRegionRequested = null != regionsStr && !regionsStr.isEmpty();
// If the delta flag is disabled in discovery or if the lease expiration
// has been disabled, redirect clients to get all instances
if ((eurekaConfig.shouldDisableDelta())
|| (!PeerAwareInstanceRegistry.getInstance().shouldAllowAccess(isRemoteRegionRequested))) {
return Response.status(Status.FORBIDDEN).build();
}
String[] regions = null;
if (!isRemoteRegionRequested) {
EurekaMonitors.GET_ALL_DELTA.increment();
} else {
regions = regionsStr.toLowerCase().split(",");
Arrays.sort(regions); // So we don't have different caches for same regions queried in different order.
EurekaMonitors.GET_ALL_DELTA_WITH_REMOTE_REGIONS.increment();
}
CurrentRequestVersion.set(Version.toEnum(version));
KeyType keyType = KeyType.JSON;
if (acceptHeader == null || !acceptHeader.contains(HEADER_JSON_VALUE)) {
keyType = KeyType.XML;
}
Key cacheKey = new Key(Key.EntityType.Application, ResponseCache.ALL_APPS_DELTA, regions, keyType,
CurrentRequestVersion.get());
if (acceptEncoding != null
&& acceptEncoding.contains(HEADER_GZIP_VALUE)) {
return Response.ok(ResponseCache.getInstance().getGZIP(cacheKey))
.header(HEADER_CONTENT_ENCODING, HEADER_GZIP_VALUE).build();
} else {
return Response.ok(ResponseCache.getInstance().get(cacheKey))
.build();
}
}
}