Java tutorial
/* * Copyright 2013 Twitter, 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.twitter.aurora.scheduler.http; import java.util.List; import java.util.Map; import java.util.Map.Entry; import java.util.Set; import javax.inject.Inject; import javax.ws.rs.DELETE; import javax.ws.rs.GET; import javax.ws.rs.POST; import javax.ws.rs.PUT; import javax.ws.rs.Path; import javax.ws.rs.PathParam; import javax.ws.rs.Produces; import javax.ws.rs.core.Context; import javax.ws.rs.core.MediaType; import javax.ws.rs.core.Response; import javax.ws.rs.core.Response.Status; import javax.ws.rs.core.UriBuilder; import javax.ws.rs.core.UriInfo; import com.google.common.annotations.VisibleForTesting; import com.google.common.base.Optional; import com.google.common.collect.ImmutableMap; import com.google.common.collect.ImmutableSet; import com.google.common.collect.Iterables; import com.twitter.aurora.scheduler.base.JobKeys; import com.twitter.aurora.scheduler.base.Query; import com.twitter.aurora.scheduler.storage.Storage; import com.twitter.aurora.scheduler.storage.entities.IAssignedTask; import com.twitter.aurora.scheduler.storage.entities.IScheduledTask; import static javax.ws.rs.core.Response.Status.NOT_FOUND; import static com.google.common.base.Preconditions.checkNotNull; import static com.twitter.aurora.gen.ScheduleStatus.RUNNING; /** * Simple redirector from the canonical name of a task to its configured HTTP port. * * <p>Forwards for GET, PUT, POST and DELETE requests using HTTP 307 allowing compliant clients to * seamlessly perform re-directed mutations. */ @Path("/mname") public class Mname { private static final Set<String> HTTP_PORT_NAMES = ImmutableSet.of("health", "http", "HTTP", "web"); private final Storage storage; @Inject public Mname(Storage storage) { this.storage = checkNotNull(storage); } @GET @Produces(MediaType.TEXT_HTML) public Response getUsage() { return Response.status(Status.BAD_REQUEST) .entity("<html>Usage: /mname/{role}/{env}/{job}/{instance}</html>").build(); } @GET @Path("/{role}/{env}/{job}/{instance}/{forward:.+}") @Produces(MediaType.TEXT_HTML) public Response getWithForwardRequest(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @PathParam("forward") String forward, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.of(forward)); } @PUT @Path("/{role}/{env}/{job}/{instance}/{forward:.+}") @Produces(MediaType.TEXT_HTML) public Response putWithForwardRequest(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @PathParam("forward") String forward, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.of(forward)); } @POST @Path("/{role}/{env}/{job}/{instance}/{forward:.+}") @Produces(MediaType.TEXT_HTML) public Response postWithForwardRequest(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @PathParam("forward") String forward, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.of(forward)); } @DELETE @Path("/{role}/{env}/{job}/{instance}/{forward:.+}") @Produces(MediaType.TEXT_HTML) public Response deleteWithForwardRequest(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @PathParam("forward") String forward, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.of(forward)); } @GET @Path("/{role}/{env}/{job}/{instance}") @Produces(MediaType.TEXT_HTML) public Response get(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.<String>absent()); } @PUT @Path("/{role}/{env}/{job}/{instance}") @Produces(MediaType.TEXT_HTML) public Response put(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.<String>absent()); } @POST @Path("/{role}/{env}/{job}/{instance}") @Produces(MediaType.TEXT_HTML) public Response post(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.<String>absent()); } @DELETE @Path("/{role}/{env}/{job}/{instance}") @Produces(MediaType.TEXT_HTML) public Response delete(@PathParam("role") String role, @PathParam("env") String env, @PathParam("job") String job, @PathParam("instance") int instanceId, @Context UriInfo uriInfo) { return get(role, env, job, instanceId, uriInfo, Optional.<String>absent()); } private Response get(String role, String env, String job, int instanceId, UriInfo uriInfo, Optional<String> forwardRequest) { IScheduledTask task = Iterables.getOnlyElement(Storage.Util.consistentFetchTasks(storage, Query.instanceScoped(JobKeys.from(role, env, job), instanceId).active()), null); if (task == null) { return respond(NOT_FOUND, "No such live instance found."); } if (task.getStatus() != RUNNING) { return respond(NOT_FOUND, "The selected instance is currently in state " + task.getStatus()); } IAssignedTask assignedTask = task.getAssignedTask(); Optional<Integer> port = getRedirectPort(assignedTask); if (!port.isPresent()) { return respond(NOT_FOUND, "The task does not have a registered http port."); } UriBuilder redirect = UriBuilder.fromPath(forwardRequest.or("/")).scheme("http") .host(assignedTask.getSlaveHost()).port(port.get()); for (Entry<String, List<String>> entry : uriInfo.getQueryParameters().entrySet()) { for (String value : entry.getValue()) { redirect.queryParam(entry.getKey(), value); } } return Response.temporaryRedirect(redirect.build()).build(); } @VisibleForTesting static Optional<Integer> getRedirectPort(IAssignedTask task) { Map<String, Integer> ports = task.isSetAssignedPorts() ? task.getAssignedPorts() : ImmutableMap.<String, Integer>of(); for (String httpPortName : HTTP_PORT_NAMES) { Integer port = ports.get(httpPortName); if (port != null) { return Optional.of(port); } } return Optional.absent(); } private Response respond(Status status, String message) { return Response.status(status).entity(message).build(); } }