[AMBARI-22883] A new REST API: GET /api/v1/hosts?format=summary or /api/v1/clusters/…

ambari-server/src/main/java/org/apache/ambari/server/api/handlers/ReadHandler.java

@@ -121,4 +121,5 @@ private void addFieldsToQuery(Request request, Query query) {
       query.addProperty(propertyId, entry.getValue());
     }
   }
+
 }

ambari-server/src/main/java/org/apache/ambari/server/api/query/render/HostSummaryRenderer.java

@@ -0,0 +1,99 @@
+/*
+ * 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.ambari.server.api.query.render;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.apache.ambari.server.api.services.Result;
+import org.apache.ambari.server.api.services.ResultImpl;
+import org.apache.ambari.server.api.util.TreeNode;
+import org.apache.ambari.server.controller.internal.HostResourceProvider;
+import org.apache.ambari.server.controller.internal.ResourceImpl;
+import org.apache.ambari.server.controller.spi.Resource;
+import org.apache.commons.lang.StringUtils;
+
+/**
+ * HostSummaryRenderere
+ *
+ * This renderer is to summarize the properties of all hosts within a cluster and returns
+ * a list of proerpties summary information: i.e
+ *
+ * summary:[
+ *  {
+ *    "operating_systems" : {
+ *      "centos6" : 5,
+ *      "centos7" : 10
+ *    }
+ *  }
+ * ]
+ *
+ */
+public class HostSummaryRenderer extends DefaultRenderer {
+
+  // A list of host properties to be summarized
+  enum HostSummaryProperties {
+    OPERATINGSYSTEMS("operating_systems");
+
+    private final String property;
+    HostSummaryProperties(String property) {
+      this.property = property;
+    }
+    public String getProperty() {
+      return property;
+    }
+  }
+
+  @Override
+  public Result finalizeResult(Result queryResult) {
+    TreeNode<Resource> queryResultTree = queryResult.getResultTree();
+    // Iterate over all returned flattened hosts and build the summary info
+    List<Object> summary = new ArrayList<>();
+    // Build all summary info
+    buildFinalizedSummary(queryResultTree, summary);
+    // Create finalized result
+    return buildFinalizedResult(summary);
+  }
+
+  private void buildFinalizedSummary(TreeNode<Resource> queryResultTree, List<Object> summary) {
+    // Build osSummary info at this time
+    Map<String, Map<String, Integer>> osSummary = new HashMap<>();
+    summary.add(osSummary);
+    Map<String, Integer> osTypeCount = new HashMap<>();
+    osSummary.put(HostSummaryProperties.OPERATINGSYSTEMS.getProperty(), osTypeCount);
+    for (TreeNode<Resource> node : queryResultTree.getChildren()) {
+      Resource resource = node.getObject();
+      String osType = (String) resource.getPropertyValue(HostResourceProvider.HOST_OS_TYPE_PROPERTY_ID);
+      if (StringUtils.isNotBlank(osType)) {
+        osTypeCount.put(osType, osTypeCount.getOrDefault(osTypeCount, 0) + 1);
+      }
+    }
+  }
+
+  private Result buildFinalizedResult(List<Object> summary) {
+    Result result = new ResultImpl(true);
+    Resource resource = new ResourceImpl(Resource.Type.Host);
+    TreeNode<Resource> summaryTree = result.getResultTree();
+    summaryTree.addChild(resource, HostResourceProvider.SUMMARY_PROPERTY_ID);
+    resource.setProperty(HostResourceProvider.SUMMARY_PROPERTY_ID, summary);
+    return result;
+  }
+}

ambari-server/src/main/java/org/apache/ambari/server/api/resources/DetachedHostResourceDefinition.java

@@ -19,6 +19,8 @@
 
 package org.apache.ambari.server.api.resources;
 
+import org.apache.ambari.server.api.query.render.HostSummaryRenderer;
+import org.apache.ambari.server.api.query.render.Renderer;
 import org.apache.ambari.server.controller.spi.Resource;
 
 
@@ -40,4 +42,13 @@ public String getPluralName() {
   public String getSingularName() {
     return "host";
   }
+
+  @Override
+  public Renderer getRenderer(String name) {
+    if (name.equals("summary")) {
+      return new HostSummaryRenderer();
+    }
+    return super.getRenderer(name);
+  }
+
 }

ambari-server/src/main/java/org/apache/ambari/server/api/resources/HostResourceDefinition.java

@@ -24,6 +24,8 @@
 import java.util.HashSet;
 import java.util.Set;
 
+import org.apache.ambari.server.api.query.render.HostSummaryRenderer;
+import org.apache.ambari.server.api.query.render.Renderer;
 import org.apache.ambari.server.controller.spi.Request;
 import org.apache.ambari.server.controller.spi.Resource;
 
@@ -54,6 +56,14 @@ public Collection<String> getDeleteDirectives() {
     return Collections.singleton(Request.DIRECTIVE_DRY_RUN);
   }
 
+  @Override
+  public Renderer getRenderer(String name) {
+    if (name.equals("summary")) {
+      return new HostSummaryRenderer();
+    }
+    return super.getRenderer(name);
+  }
+
   @Override
   public Set<SubResourceDefinition> getSubResourceDefinitions() {
     Set<SubResourceDefinition> subs = new HashSet<>();

ambari-server/src/main/java/org/apache/ambari/server/api/services/HostService.java

@@ -28,6 +28,7 @@
 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.HttpHeaders;
 import javax.ws.rs.core.Response;
@@ -133,7 +134,8 @@ public Response getHost(String body, @Context HttpHeaders headers, @Context UriI
     @ApiResponse(code = HttpStatus.SC_FORBIDDEN, message = MSG_PERMISSION_DENIED),
     @ApiResponse(code = HttpStatus.SC_INTERNAL_SERVER_ERROR, message = MSG_SERVER_ERROR),
   })
-  public Response getHosts(String body, @Context HttpHeaders headers, @Context UriInfo ui) {
+  public Response getHosts(String body, @Context HttpHeaders headers, @Context UriInfo ui,
+                           @ApiParam(value = "summary", required = false) @QueryParam("format") String format) {
     return handleRequest(headers, body, ui, Request.Type.GET,
         createHostResource(m_clusterName, null));
   }

ambari-server/src/main/java/org/apache/ambari/server/controller/HostResponse.java

@@ -146,6 +146,29 @@ public class HostResponse {
 
   private MaintenanceState maintenanceState;
 
+  /**
+   * Summary information of all hosts in a cluster or multiple clusters
+   *
+   * The response json schema is:
+   * {
+   * "Hosts" : {
+   *     "cluster_name" : "c1",
+   *     "summary" : [
+   *       {
+   *         "operating_systems" : [
+   *           {
+   *             "centos6" : 2
+   *           },
+   *           {
+   *             "centos7" : 5
+   *           }
+   *         ]
+   *       }
+   *     ]
+   * }
+   */
+  private List<Object> hostsSummary;
+
   public HostResponse(String hostname, String clusterName,
                       String ipv4, int cpuCount, int phCpuCount, String osArch, String osType,
                       long totalMemBytes,
@@ -421,6 +444,21 @@ public RecoveryReport getRecoveryReport() {
     return recoveryReport;
   }
 
+  /**
+   * Set the hostsSummary
+   */
+  public void setHostsSummary(List<Object> hostsSummary) {
+    this.hostsSummary = hostsSummary;
+  }
+
+  /**
+   * Get the aggregation info of hosts in a cluster or in multiple clusters
+   */
+  @ApiModelProperty(name = HostResourceProvider.SUMMARY_PROPERTY_ID)
+  public List<Object> getHostsSummary() {
+    return hostsSummary;
+  }
+
   /**
    * Set the detailed recovery report
    */

ambari-server/src/main/java/org/apache/ambari/server/controller/internal/DefaultProviderModule.java

@@ -132,6 +132,8 @@ protected ResourceProvider createResourceProvider(Resource.Type type) {
         return new ArtifactResourceProvider(managementController);
       case RemoteCluster:
         return new RemoteClusterResourceProvider();
+      case Host:
+        return new HostResourceProvider(managementController);
       default:
         LOGGER.debug("Delegating creation of resource provider for: {} to the AbstractControllerResourceProvider", type.getInternalType());
         return AbstractControllerResourceProvider.getResourceProvider(type, managementController);

ambari-server/src/main/java/org/apache/ambari/server/controller/internal/HostResourceProvider.java

@@ -116,6 +116,7 @@ public class HostResourceProvider extends AbstractControllerResourceProvider {
   public static final String STATE_PROPERTY_ID = "host_state";
   public static final String TOTAL_MEM_PROPERTY_ID = "total_mem";
   public static final String ATTRIBUTES_PROPERTY_ID = "attributes";
+  public static final String SUMMARY_PROPERTY_ID = "summary";
 
   public static final String HOST_CLUSTER_NAME_PROPERTY_ID = RESPONSE_KEY + PropertyHelper.EXTERNAL_PATH_SEP + CLUSTER_NAME_PROPERTY_ID;
   public static final String HOST_CPU_COUNT_PROPERTY_ID = RESPONSE_KEY + PropertyHelper.EXTERNAL_PATH_SEP + CPU_COUNT_PROPERTY_ID;
@@ -139,7 +140,7 @@ public class HostResourceProvider extends AbstractControllerResourceProvider {
   public static final String HOST_RECOVERY_SUMMARY_PROPERTY_ID = RESPONSE_KEY + PropertyHelper.EXTERNAL_PATH_SEP + RECOVERY_SUMMARY_PROPERTY_ID;
   public static final String HOST_STATE_PROPERTY_ID = RESPONSE_KEY + PropertyHelper.EXTERNAL_PATH_SEP + STATE_PROPERTY_ID;
   public static final String HOST_TOTAL_MEM_PROPERTY_ID = RESPONSE_KEY + PropertyHelper.EXTERNAL_PATH_SEP + TOTAL_MEM_PROPERTY_ID;
-  public static final String HOST_ATTRIBUTES_PROPERTY_ID = PropertyHelper.getPropertyId(RESPONSE_KEY,ATTRIBUTES_PROPERTY_ID);
+  public static final String HOST_ATTRIBUTES_PROPERTY_ID = PropertyHelper.getPropertyId(RESPONSE_KEY, ATTRIBUTES_PROPERTY_ID);
 
   public static final String BLUEPRINT_PROPERTY_ID = "blueprint";
   public static final String HOST_GROUP_PROPERTY_ID = "host_group";
@@ -154,6 +155,7 @@ public class HostResourceProvider extends AbstractControllerResourceProvider {
   public static Map<Resource.Type, String> keyPropertyIds = ImmutableMap.<Resource.Type, String>builder()
       .put(Resource.Type.Host, HOST_HOST_NAME_PROPERTY_ID)
       .put(Resource.Type.Cluster, HOST_CLUSTER_NAME_PROPERTY_ID)
+      .put(Resource.Type.HostComponent, HOST_OS_TYPE_PROPERTY_ID)
       .build();
 
   /**
@@ -195,7 +197,7 @@ public class HostResourceProvider extends AbstractControllerResourceProvider {
   /**
    * Create a  new resource provider for the given management controller.
    *
-   * @param managementController  the management controller
+   * @param managementController the management controller
    */
   @AssistedInject
   HostResourceProvider(@Assisted AmbariManagementController managementController) {
@@ -214,9 +216,9 @@ public class HostResourceProvider extends AbstractControllerResourceProvider {
   @Override
   protected RequestStatus createResourcesAuthorized(final Request request)
       throws SystemException,
-          UnsupportedPropertyException,
-          ResourceAlreadyExistsException,
-          NoSuchParentResourceException {
+      UnsupportedPropertyException,
+      ResourceAlreadyExistsException,
+      NoSuchParentResourceException {
 
     RequestStatusResponse createResponse = null;
     if (isHostGroupRequest(request)) {
@@ -238,6 +240,11 @@ public Void invoke() throws AmbariException, AuthorizationException {
   @Override
   protected Set<Resource> getResourcesAuthorized(Request request, Predicate predicate)
       throws SystemException, UnsupportedPropertyException, NoSuchResourceException, NoSuchParentResourceException {
+    return getHostResource(request, predicate);
+  }
+
+  private Set<Resource> getHostResource(Request request, Predicate predicate)
+      throws SystemException, UnsupportedPropertyException, NoSuchResourceException, NoSuchParentResourceException {
 
     final Set<HostRequest> requests = new HashSet<>();