content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.kafka.connect.runtime.rest.resources;
  
  import org.apache.kafka.common.utils.Time;
  import org.apache.kafka.connect.runtime.Herder;
  import org.apache.kafka.connect.runtime.rest.RestRequestTimeout;
  import org.apache.kafka.connect.runtime.rest.entities.ServerInfo;
  import org.apache.kafka.connect.runtime.rest.entities.WorkerStatus;
  import org.apache.kafka.connect.util.FutureCallback;
  import org.apache.kafka.connect.util.StagedTimeoutException;
  
  import java.util.concurrent.ExecutionException;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.TimeoutException;
  
  import io.swagger.v3.oas.annotations.Operation;
  import jakarta.inject.Inject;
  import jakarta.ws.rs.GET;
  import jakarta.ws.rs.Path;
  import jakarta.ws.rs.Produces;
  import jakarta.ws.rs.core.MediaType;
  import jakarta.ws.rs.core.Response;
  
  @Path("/")
  @Produces(MediaType.APPLICATION_JSON)
  public class RootResource {
  
      private final Herder herder;
      private final RestRequestTimeout requestTimeout;
      private final Time time;
  
      @Inject
      public RootResource(Herder herder, RestRequestTimeout requestTimeout) {
          this(herder, requestTimeout, Time.SYSTEM);
      }
  
      // For testing only
      RootResource(Herder herder, RestRequestTimeout requestTimeout, Time time) {
          this.herder = herder;
          this.requestTimeout = requestTimeout;
          this.time = time;
      }
  
      @GET
      @Operation(summary = "Get details about this Connect worker and the ID of the Kafka cluster it is connected to")
      public ServerInfo serverInfo() {
          return new ServerInfo(herder.kafkaClusterId());
      }
  
      @GET
      @Path("/health")
      @Operation(summary = "Health check endpoint to verify worker readiness and liveness")
      public Response healthCheck() throws Throwable {
          WorkerStatus workerStatus;
          int statusCode;
          try {
              FutureCallback<Void> cb = new FutureCallback<>();
              herder.healthCheck(cb);
  
              long timeoutNs = TimeUnit.MILLISECONDS.toNanos(requestTimeout.healthCheckTimeoutMs());
              long deadlineNs = timeoutNs + time.nanoseconds();
              time.waitForFuture(cb, deadlineNs);
  
              statusCode = Response.Status.OK.getStatusCode();
              workerStatus = WorkerStatus.healthy();
          } catch (TimeoutException e) {
              String statusDetails = e instanceof StagedTimeoutException
                      ? ((StagedTimeoutException) e).stage().summarize()
                      : null;
              if (!herder.isReady()) {
                  statusCode = Response.Status.SERVICE_UNAVAILABLE.getStatusCode();
                  workerStatus = WorkerStatus.starting(statusDetails);
              } else {
                  statusCode = Response.Status.INTERNAL_SERVER_ERROR.getStatusCode();
                  workerStatus = WorkerStatus.unhealthy(statusDetails);
              }
          } catch (ExecutionException e) {
              throw e.getCause();
          }
  
          return Response.status(statusCode).entity(workerStatus).build();
      }
  
  }
  