json_query过滤器错误-模板字符串时模板错误:预期标记'，‘

Question

我正在尝试使用json_query过滤器来解析所需的JSON数据。

可供选择的剧本任务：

- name: Print items in option
  ansible.builtin.debug:
    msg: "{{ clust_opts | community.general.json_query('defaultReplicaSet.topology.\"dc1-indb-tst1:3306\" | [].option['memberWeight']')' }}"

我还在我的剧本中尝试了以下几点--这导致了同样的错误：

- name: Print items in option
  ansible.builtin.debug:
    msg: "{{ clust_opts | community.general.json_query('defaultReplicaSet.topology.[?option == 'memberWeight']')' }}"

错误信息：

TASK [Print items in option] **************************************************************************************************
fatal: [dc1-indb-tst1]: FAILED! => {"msg": "template error while templating string: expected token ',', got 'memberWeight'. String: {{ clust_opts | json_query('defaultReplicaSet.topology.[?option == 'memberWeight']')' }}"}

JSON来解析以下数据：

{
    "clusterName": "idb_test",
    "defaultReplicaSet": {
        "globalOptions": [
            {
                "option": "groupName",
                "value": "8f9e6040-F10s-11ec-b244-005056a4645c",
                "variable": "group_replication_group_name"
            },
            {
                "option": "memberSslMode",
                "value": "REQUIRED",
                "variable": "group_replication_ssl_mode"
            },
            {
                "option": "disableClone",
                "value": false
            }
        ],
        "tags": {
            "dc1-indb-tst1:3306": [],
            "dc1-indb-tst2:3306": [],
            "dc1-indb-tst3:3306": [],
            "global": []
        },
        "topology": {
            "dc1-indb-tst1:3306": [
                {
                    "option": "autoRejoinTries",
                    "value": "3",
                    "variable": "group_replication_autorejoin_tries"
                },
                {
                    "option": "consistency",
                    "value": "EVENTUAL",
                    "variable": "group_replication_consistency"
                },
                {
                    "option": "exitStateAction",
                    "value": "READ_ONLY",
                    "variable": "group_replication_exit_state_action"
                },
                {
                    "option": "expelTimeout",
                    "value": "5",
                    "variable": "group_replication_member_expel_timeout"
                },
                {
                    "option": "groupSeeds",
                    "value": "dc1-indb-tst2:33061,dc1-indb-tst3:33061",
                    "variable": "group_replication_group_seeds"
                },
                {
                    "option": "ipAllowlist",
                    "value": "AUTOMATIC",
                    "variable": "group_replication_ip_allowlist"
                },
                {
                    "option": "ipWhitelist",
                    "value": "AUTOMATIC",
                    "variable": "group_replication_ip_whitelist"
                },
                {
                    "option": "localAddress",
                    "value": "dc1-indb-tst1:33061",
                    "variable": "group_replication_local_address"
                },
                {
                    "option": "memberWeight",
                    "value": "50",
                    "variable": "group_replication_member_weight"
                },
                {
                    "value": "WRITESET",
                    "variable": "binlog_transaction_dependency_tracking"
                },
                {
                    "value": "LOGICAL_CLOCK",
                    "variable": "replica_parallel_type"
                },
                {
                    "value": "4",
                    "variable": "replica_parallel_workers"
                },
                {
                    "value": "ON",
                    "variable": "replica_preserve_commit_order"
                },
                {
                    "value": "XXHASH64",
                    "variable": "transaction_write_set_extraction"
                }
            ],
            "dc1-indb-tst2:3306": [
                {
                    "option": "autoRejoinTries",
                    "value": "3",
                    "variable": "group_replication_autorejoin_tries"
                },
                {
                    "option": "consistency",
                    "value": "EVENTUAL",
                    "variable": "group_replication_consistency"
                },
                {
                    "option": "exitStateAction",
                    "value": "READ_ONLY",
                    "variable": "group_replication_exit_state_action"
                },
                {
                    "option": "expelTimeout",
                    "value": "5",
                    "variable": "group_replication_member_expel_timeout"
                },
                {
                    "option": "groupSeeds",
                    "value": "dc1-indb-tst1:33061,dc1-indb-tst3:33061",
                    "variable": "group_replication_group_seeds"
                },
                {
                    "option": "ipAllowlist",
                    "value": "AUTOMATIC",
                    "variable": "group_replication_ip_allowlist"
                },
                {
                    "option": "ipWhitelist",
                    "value": "AUTOMATIC",
                    "variable": "group_replication_ip_whitelist"
                },
                {
                    "option": "localAddress",
                    "value": "dc1-indb-tst2:33061",
                    "variable": "group_replication_local_address"
                },
                {
                    "option": "memberWeight",
                    "value": "50",
                    "variable": "group_replication_member_weight"
                },
                {
                    "value": "WRITESET",
                    "variable": "binlog_transaction_dependency_tracking"
                },
                {
                    "value": "LOGICAL_CLOCK",
                    "variable": "replica_parallel_type"
                },
                {
                    "value": "4",
                    "variable": "replica_parallel_workers"
                },
                {
                    "value": "ON",
                    "variable": "replica_preserve_commit_order"
                },
                {
                    "value": "XXHASH64",
                    "variable": "transaction_write_set_extraction"
                }
            ],
            "dc1-indb-tst3:3306": [
                {
                    "option": "autoRejoinTries",
                    "value": "3",
                    "variable": "group_replication_autorejoin_tries"
                },
                {
                    "option": "consistency",
                    "value": "EVENTUAL",
                    "variable": "group_replication_consistency"
                },
                {
                    "option": "exitStateAction",
                    "value": "READ_ONLY",
                    "variable": "group_replication_exit_state_action"
                },
                {
                    "option": "expelTimeout",
                    "value": "5",
                    "variable": "group_replication_member_expel_timeout"
                },
                {
                    "option": "groupSeeds",
                    "value": "dc1-indb-tst1:33061,dc1-indb-tst2:33061",
                    "variable": "group_replication_group_seeds"
                },
                {
                    "option": "ipAllowlist",
                    "value": "AUTOMATIC",
                    "variable": "group_replication_ip_allowlist"
                },
                {
                    "option": "ipWhitelist",
                    "value": "AUTOMATIC",
                    "variable": "group_replication_ip_whitelist"
                },
                {
                    "option": "localAddress",
                    "value": "dc1-indb-tst3:33061",
                    "variable": "group_replication_local_address"
                },
                {
                    "option": "memberWeight",
                    "value": "50",
                    "variable": "group_replication_member_weight"
                },
                {
                    "value": "WRITESET",
                    "variable": "binlog_transaction_dependency_tracking"
                },
                {
                    "value": "LOGICAL_CLOCK",
                    "variable": "replica_parallel_type"
                },
                {
                    "value": "4",
                    "variable": "replica_parallel_workers"
                },
                {
                    "value": "ON",
                    "variable": "replica_preserve_commit_order"
                },
                {
                    "value": "XXHASH64",
                    "variable": "transaction_write_set_extraction"
                }
            ]
        }
    }
}

最终目标是能够在option字段中查找数据并返回与其关联的value。

因此，在我的示例中，我希望找到特定系统的memberWeight并返回value。

我正在查看dc1-indb-tst1:3306，特别是memberWeight，它应该返回50 -但是我得到了上面的错误。

Answer 1

TL;DR；

在这个用例中，一个有效的调试任务是：

- ansible.builtin.debug:
    msg: >-
      {{
        clust_opts | community.general.json_query('
          defaultReplicaSet
            .topology
            ."dc1-indb-tst1:3306"[?
              option == `memberWeight`
            ].value | [0]
        ')
      }}

这意味着：

ok: [localhost] => 
  msg: '50'

您所收到的错误是因为您忘记在'查询中转义单引号JMESPath。

用引号转义来缓解你自己的生活的一个想法是使用YAML折叠块表示法

- ansible.builtin.debug:
    msg: >-
      I don't have to escape single (')
      nor double (") quote in this string,
      it is delimited only by the fact that it is further indented
      than the block where the folded block starts.

现在，对于您的JMESPath查询，在这两个查询中都有部分解决方案，因此，如果将两者混合在一起，您几乎可以得到预期的结果。

一个小小的解释词，地图的性质被询问用点.符号。而数组的元素是通过方括号符号[]查询的。

所以，从你的第一次尝试，这部分是正确的：

defaultReplicaSet.topology."dc1-indb-tst1:3306"

在第二部分，这一部分是正确的：

[?option == 'memberWeight']

你们在一起

defaultReplicaSet
  .topology
  ."dc1-indb-tst1:3306"[?
    option == 'memberWeight'
  ]

它给出了整个对象：

[
  {
    "option": "memberWeight",
    "value": "50",
    "variable": "group_replication_member_weight"
  }
]

现在只需查询该值，并返回它的第一个结果，因此添加：

.value | [0]

管道表达式是用来停止投影的，有关这方面的更多资料，请参阅有关文件。。

因此，您的查询结果是：

defaultReplicaSet
  .topology
  ."dc1-indb-tst1:3306"[?
    option == `memberWeight`
  ].value | [0]

--请注意：我把单引号'换成了后面的`，这是json_query中的提议。

在上面的例子中，使用backticks引用文字可以避免转义引号并保持可读性。

实际上，在JMESPath中，它们都代表文字。在这两者之间有一个细微的区别，单引号是一个文字表达式。和背包表示原始的文字字符串。，但在手头的情况下，is将采取相同的行动。

您的debug任务应该是：

- ansible.builtin.debug:
    msg: >-
      {{
        clust_opts | community.general.json_query('
          defaultReplicaSet
            .topology
            ."dc1-indb-tst1:3306"[?
              option == `memberWeight`
            ].value | [0]
        ')
      }}

这将产生：

TASK [ansible.builtin.debug] *********************************************
ok: [localhost] => 
  msg: '50'