從URI輸出的JSON輸出的Ansible循環調用

Question

我一直試圖讓它工作一段時間，但我無法這樣做。我希望這是我很想念的東西。

我想解析使用with_items的任務的JSON輸出。我知道最終組件的變量列表將會在結果數組中出現。

- name: Get list of components for each host 
     uri: url="http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/{{ hostvars[item].ansible_host_fqdn }}" 
     method=GET 
     force_basic_auth=yes 
     user=admin 
     password=admin 
     HEADER_X-Requested-By="ambari" 
     status_code=200,201,202 
     return_content=yes 
     register: list_of_components 
     with_items: "{{ groups['hadoop_cluster'] }}" 

# - debug: msg="Components are {{ (list_of_components.results|from_json)|json_query('content.host_components[*].HostRoles.component_name') }}" 
    #- debug: var=list_of_components 
# - debug: msg="Components are {{ list_of_components.results[0].item.content.host_components[*].HostRoles.component_name }}" 
    - debug: msg="Components are {{ item }}" 
     with_items: "{{ list_of_components.results|from_json }}" 

從「獲取每個主機的組件列表」任務的示例調試輸出顯示在下面。我試圖得到（主機，component_name）的元組，我可以通過循環在下一個任務

我有沒有提到，我對Ansible的理解是相當有限的。

ok: [localhost] => (item=slave2) => { 
    "changed": false, 
    "connection": "close", 
    "content": "{\n \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster\",\n \"Hosts\" : {\n \"cluster_name\" : \"pstl-cluster\",\n \"cpu_count\" : 1,\n \"disk_info\" : [\n  {\n  \"available\" : \"36725348\",\n  \"device\" : \"/dev/mapper/centos-root\",\n  \"used\" : \"2540208\",\n  \"percent\" : \"7%\",\n  \"size\" : \"39265556\",\n  \"type\" : \"xfs\",\n  \"mountpoint\" : \"/\"\n  },\n  {\n  \"available\" : \"932372\",\n  \"device\" : \"devtmpfs\",\n  \"used\" : \"0\",\n  \"percent\" : \"0%\",\n  \"size\" : \"932372\",\n  \"type\" : \"devtmpfs\",\n  \"mountpoint\" : \"/dev\"\n  },\n  {\n  \"available\" : \"942088\",\n  \"device\" : \"tmpfs\",\n  \"used\" : \"0\",\n  \"percent\" : \"0%\",\n  \"size\" : \"942088\",\n  \"type\" : \"tmpfs\",\n  \"mountpoint\" : \"/dev/shm\"\n  },\n  {\n  \"available\" : \"933636\",\n  \"device\" : \"tmpfs\",\n  \"used\" : \"8452\",\n  \"percent\" : \"1%\",\n  \"size\" : \"942088\",\n  \"type\" : \"tmpfs\",\n  \"mountpoint\" : \"/run\"\n  },\n  {\n  \"available\" : \"341996\",\n  \"device\" : \"/dev/sda1\",\n  \"used\" : \"166592\",\n  \"percent\" : \"33%\",\n  \"size\" : \"508588\",\n  \"type\" : \"xfs\",\n  \"mountpoint\" : \"/boot\"\n  },\n  {\n  \"available\" : \"75495164\",\n  \"device\" : \"vagrant\",\n  \"used\" : \"168429828\",\n  \"percent\" : \"70%\",\n  \"size\" : \"243924992\",\n  \"type\" : \"vboxsf\",\n  \"mountpoint\" : \"/vagrant\"\n  },\n  {\n  \"available\" : \"75495164\",\n  \"device\" : \"vagrant_data\",\n  \"used\" : \"168429828\",\n  \"percent\" : \"70%\",\n  \"size\" : \"243924992\",\n  \"type\" : \"vboxsf\",\n  \"mountpoint\" : \"/vagrant_data\"\n  }\n ],\n \"host_health_report\" : \"\",\n \"host_name\" : \"slave2.mycluster\",\n \"host_state\" : \"HEALTHY\",\n \"host_status\" : \"UNHEALTHY\",\n \"ip\" : \"192.168.0.22\",\n \"last_agent_env\" : {\n  \"stackFoldersAndFiles\" : [ ],\n  \"alternatives\" : [ ],\n  \"existingUsers\" : [ ],\n  \"existingRepos\" : [ ],\n  \"installedPackages\" : [ ],\n  \"hostHealth\" : {\n  \"activeJavaProcs\" : [ ],\n  \"agentTimeStampAtReporting\" : 1481214773737,\n  \"serverTimeStampAtReporting\" : 1481214771036,\n  \"liveServices\" : [\n   {\n   \"desc\" : \"● ntpd.service - Network Time Service\\n Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)\\n Active: inactive (dead)\\n\\nDec 07 20:16:57 slave2.mycluster systemd[1]: Stopped Network Time Service.\\n\",\n   \"status\" : \"Unhealthy\",\n   \"name\" : \"ntpd\"\n   }\n  ]\n  },\n  \"umask\" : 18,\n  \"transparentHugePage\" : \"\",\n  \"firewallRunning\" : false,\n  \"firewallName\" : \"iptables\",\n  \"reverseLookup\" : true\n },\n \"last_heartbeat_time\" : 1481214800798,\n \"last_registration_time\" : 1481160539338,\n \"maintenance_state\" : \"OFF\",\n \"os_arch\" : \"x86_64\",\n \"os_family\" : \"redhat7\",\n \"os_type\" : \"centos7\",\n \"ph_cpu_count\" : 1,\n \"public_host_name\" : \"slave2.mycluster\",\n \"rack_info\" : \"/default-rack\",\n \"recovery_report\" : {\n  \"summary\" : \"RECOVERABLE\",\n  \"component_reports\" : [ ]\n },\n \"recovery_summary\" : \"RECOVERABLE\",\n \"total_mem\" : 1884176,\n \"desired_configs\" : {\n  \"ams-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-grafana-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-grafana-ini\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-hbase-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-hbase-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-hbase-policy\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-hbase-security-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-hbase-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-ssl-client\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ams-ssl-server\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"capacity-scheduler\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"cluster-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"core-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"falcon-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"falcon-runtime.properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"falcon-startup.properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hadoop-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hadoop-policy\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hbase-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hbase-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hbase-policy\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hbase-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hcat-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hdfs-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hdfs-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hive-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hive-exec-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hive-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hive-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"hiveserver2-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"kafka-broker\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"kafka-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"kafka-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"mapred-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"mapred-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"oozie-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"oozie-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"oozie-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"pig-env\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"pig-log4j\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"pig-properties\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"ranger-hbase-audit\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hbase-plugin-properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hbase-policymgr-ssl\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hbase-security\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hdfs-audit\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hdfs-plugin-properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hdfs-policymgr-ssl\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hdfs-security\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hive-audit\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hive-plugin-properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hive-policymgr-ssl\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-hive-security\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-kafka-audit\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-kafka-plugin-properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-kafka-policymgr-ssl\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-kafka-security\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-yarn-audit\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-yarn-plugin-properties\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-yarn-policymgr-ssl\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ranger-yarn-security\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"slider-client\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"slider-env\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"slider-log4j\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-defaults\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-env\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-hive-site-override\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-log4j-properties\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-metrics-properties\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-thrift-fairscheduler\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"spark-thrift-sparkconf\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"ssl-client\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"ssl-server\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"tez-env\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"tez-site\" : {\n  \"default\" : \"INITIAL\"\n  },\n  \"webhcat-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"webhcat-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"webhcat-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"yarn-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"yarn-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"yarn-site\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"zoo.cfg\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"zookeeper-env\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  },\n  \"zookeeper-log4j\" : {\n  \"default\" : \"TOPOLOGY_RESOLVED\"\n  }\n }\n },\n \"alerts_summary\" : {\n \"CRITICAL\" : 3,\n \"MAINTENANCE\" : 0,\n \"OK\" : 2,\n \"UNKNOWN\" : 0,\n \"WARNING\" : 0\n },\n \"kerberos_identities\" : [\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/kerberos_identities/HTTP%2Fslave2.mycluster%40%24%7Bkerberos-env%2Frealm%7D\",\n  \"KerberosIdentity\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"principal_name\" : \"HTTP/slave2.mycluster@${kerberos-env/realm}\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/kerberos_identities/ambari-qa-pstl-cluster%40%24%7Bkerberos-env%2Frealm%7D\",\n  \"KerberosIdentity\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"principal_name\" : \"ambari-qa-pstl-cluster@${kerberos-env/realm}\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/kerberos_identities/kafka%2Fslave2.mycluster%40%24%7Bkerberos-env%2Frealm%7D\",\n  \"KerberosIdentity\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"principal_name\" : \"kafka/slave2.mycluster@${kerberos-env/realm}\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/kerberos_identities/zookeeper%2Fslave2.mycluster%40%24%7Bkerberos-env%2Frealm%7D\",\n  \"KerberosIdentity\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"principal_name\" : \"zookeeper/slave2.mycluster@${kerberos-env/realm}\"\n  }\n }\n ],\n \"alerts\" : [\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/alerts/1\",\n  \"Alert\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"definition_id\" : 70,\n  \"definition_name\" : \"ambari_agent_disk_usage\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"id\" : 1,\n  \"service_name\" : \"AMBARI\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/alerts/6\",\n  \"Alert\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"definition_id\" : 71,\n  \"definition_name\" : \"ambari_server_agent_heartbeat\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"id\" : 6,\n  \"service_name\" : \"AMBARI\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/alerts/8\",\n  \"Alert\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"definition_id\" : 52,\n  \"definition_name\" : \"ams_metrics_monitor_process\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"id\" : 8,\n  \"service_name\" : \"AMBARI_METRICS\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/alerts/9\",\n  \"Alert\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"definition_id\" : 63,\n  \"definition_name\" : \"kafka_broker_process\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"id\" : 9,\n  \"service_name\" : \"KAFKA\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/alerts/7\",\n  \"Alert\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"definition_id\" : 69,\n  \"definition_name\" : \"zookeeper_server_process\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"id\" : 7,\n  \"service_name\" : \"ZOOKEEPER\"\n  }\n }\n ],\n \"stack_versions\" : [\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/stack_versions/1\",\n  \"HostStackVersions\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"host_name\" : \"slave2.mycluster\",\n  \"id\" : 1,\n  \"repository_version\" : 1,\n  \"stack\" : \"HDP\",\n  \"version\" : \"2.4\"\n  }\n }\n ],\n \"host_components\" : [\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/host_components/KAFKA_BROKER\",\n  \"HostRoles\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"component_name\" : \"KAFKA_BROKER\",\n  \"host_name\" : \"slave2.mycluster\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/host_components/METRICS_MONITOR\",\n  \"HostRoles\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"component_name\" : \"METRICS_MONITOR\",\n  \"host_name\" : \"slave2.mycluster\"\n  }\n },\n {\n  \"href\" : \"http://192.168.0.11:8080/api/v1/clusters/pstl-cluster/hosts/slave2.mycluster/host_components/ZOOKEEPER_SERVER\",\n  \"HostRoles\" : {\n  \"cluster_name\" : \"pstl-cluster\",\n  \"component_name\" : \"ZOOKEEPER_SERVER\",\n  \"host_name\" : \"slave2.mycluster\"\n  }\n }\n ]\n}", 
    "content_type": "text/plain", 
    "expires": "Thu, 01 Jan 1970 00:00:00 GMT", 
    "invocation": { 
     "module_args": { 
      "HEADER_X-Requested-By": "ambari", 
      "backup": null, 
      "body": null, 
      "body_format": "raw", 
      "content": null, 
      "creates": null, 
      "delimiter": null, 
      "dest": null, 
      "directory_mode": null, 
      "follow": false, 
      "follow_redirects": "safe", 
      "force": false, 
      "force_basic_auth": true, 
      "group": null, 
      "headers": { 
       "Authorization": "Basic YWRtaW46YWRtaW4=", 
       "X-Requested-By": "ambari" 
      }, 
      "http_agent": "ansible-httpget", 
      "method": "GET", 
      "mode": null, 
      "owner": null, 
      "password": "admin", 
      "regexp": null, 
      "remote_src": null, 
      "removes": null, 
      "return_content": true, 
      "selevel": null, 
      "serole": null, 
      "setype": null, 
      "seuser": null, 
      "src": null, 
      "status_code": [ 
       "200", 
       "201", 
       "202", 
       "404" 
      ], 
      "timeout": 30, 
      "unsafe_writes": null, 
      "url": "<link_to_url>", 
      "url_password": "admin", 
      "url_username": "admin", 
      "use_proxy": true, 
      "user": "admin", 
      "validate_certs": true 
     }, 
     "module_name": "uri" 
    }, 
    "item": "slave2", 
    "msg": "OK (unknown bytes)", 
    "redirected": false, 
    "server": "Jetty(8.1.17.v20150415)", 
    "set_cookie": "AMBARISESSIONID=1izzm1ej0m6baujfzms48zhau;Path=/;HttpOnly", 
    "status": 200, 
    "url": "<link_to_uri>", 
    "user": "admin", 
    "vary": "Accept-Encoding, User-Agent", 
    "x_frame_options": "DENY", 
    "x_xss_protection": "1; mode=block" 
} 

Answer 1

嘗試：

- debug: msg="{{ item.host_name }} {{ item.component_name }}" 
    with_items: "{{ list_of_components.results | map(attribute='content') | map('from_json') | map(attribute='host_components') | sum(start=[]) | map(attribute='HostRoles') | list }}" 

代碼沒有進行測試！

的理念是：採取list_of_components.results，只需要content出來的，適用from_json過濾器，只需要host_components列表出來的，扁平化的組件列表列表插入一個列表與sum，採取HostRoles出來，轉換爲list（來自地圖結果）。

所以這個代碼應該給你這樣的項目清單：

{ 
    "cluster_name" : "pstl-cluster", 
    "component_name" : "METRICS_MONITOR", 
    "host_name" : "slave2.mycluster" 
}