Ambari的API调用

　　GET api/v1/clusters/HDP/configurations可以获得所有的配置信息（例如，http://hdp0:8080/api/v1/clusters/HDP/configurations）；但是只是一级信息；

　　比如我想要获得yarn的scheduler的节点信息，将会找到：

{
      "href" : "http://hdp0:8080/api/v1/clusters/HDP/configurations?type=capacity-scheduler&tag=version1",
      "tag" : "version1",
      "type" : "capacity-scheduler",
      "version" : 1,
      "Config" : {
        "cluster_name" : "HDP",
        "stack_id" : "HDP-2.6"
      }
    }

　　这里注意，type就是配置页面的配置项的名称，在配置页面中该配置项为“Capacity Scheduler”，处理的时候，中间的空格处理为"-"，全字小写即使节点名称。然后，通过访问href指定的链接：http://hdp0:8080/api/v1/clusters/HDP/configurations?type=capacity-scheduler&tag=version1就可以看到该配置的详细信息

{
  "href" : "http://hdp0:8080/api/v1/clusters/HDP/configurations?type=capacity-scheduler&tag=version1",
  "items" : [
    {
      "href" : "http://hdp0:8080/api/v1/clusters/HDP/configurations?type=capacity-scheduler&tag=version1",
      "tag" : "version1",
      "type" : "capacity-scheduler",
      "version" : 1,
      "Config" : {
        "cluster_name" : "HDP",
        "stack_id" : "HDP-2.6"
      },
      "properties" : {
        "capacity-scheduler" : "null",
        "yarn.scheduler.capacity.default.minimum-user-limit-percent" : "100",
        "yarn.scheduler.capacity.maximum-am-resource-percent" : "0.2",
        "yarn.scheduler.capacity.maximum-applications" : "10000",
        "yarn.scheduler.capacity.node-locality-delay" : "40",
        "yarn.scheduler.capacity.resource-calculator" : "org.apache.hadoop.yarn.util.resource.DefaultResourceCalculator",
        "yarn.scheduler.capacity.root.accessible-node-labels" : "*",
        "yarn.scheduler.capacity.root.acl_administer_queue" : "*",
        "yarn.scheduler.capacity.root.capacity" : "100",
        "yarn.scheduler.capacity.root.default.acl_administer_jobs" : "*",
        "yarn.scheduler.capacity.root.default.acl_submit_applications" : "*",
        "yarn.scheduler.capacity.root.default.capacity" : "100",
        "yarn.scheduler.capacity.root.default.maximum-capacity" : "100",
        "yarn.scheduler.capacity.root.default.state" : "RUNNING",
        "yarn.scheduler.capacity.root.default.user-limit-factor" : "1",
        "yarn.scheduler.capacity.root.queues" : "default"
      }
    }
  ]
}

参考：https://github.com/apache/ambari/blob/trunk/ambari-server/docs/api/v1/configuration.md