Question

我正在运行Ansible剧本。在YAML文件“ jinja.yaml”中，我具有以下jinja2模板。

{% set cnt = 0 %} 
{% for x in range(4, 20) %}
    {% for y in range(1, 251) %}
        - pool_name: pool_{{ cnt }}
          {% set cnt = cnt + 1 %}
          pool_member: 10.30.{{ x }}.{{ y }}
{% endfor %} {% endfor %}

以下是Ansilbe代码中的代码段：

tasks:
    - name: XXX
      set_fact:
        members: "{{ lookup('template', 'jinja.yaml') | from_yaml}}"

运行Ansible剧本时，出现以下错误消息：

 return loader.get_single_data()
  File "/usr/lib/python2.7/dist-packages/yaml/constructor.py", line 37, in get_single_data
    node = self.get_single_node()
  File "/usr/lib/python2.7/dist-packages/yaml/composer.py", line 36, in get_single_node
    document = self.compose_document()
  File "/usr/lib/python2.7/dist-packages/yaml/composer.py", line 55, in compose_document
    node = self.compose_node(None, None)
  File "/usr/lib/python2.7/dist-packages/yaml/composer.py", line 82, in compose_node
    node = self.compose_sequence_node(anchor)
  File "/usr/lib/python2.7/dist-packages/yaml/composer.py", line 111, in compose_sequence_node
    node.value.append(self.compose_node(node, index))
  File "/usr/lib/python2.7/dist-packages/yaml/composer.py", line 84, in compose_node
    node = self.compose_mapping_node(anchor)
  File "/usr/lib/python2.7/dist-packages/yaml/composer.py", line 127, in compose_mapping_node
    while not self.check_event(MappingEndEvent):
  File "/usr/lib/python2.7/dist-packages/yaml/parser.py", line 98, in check_event
    self.current_event = self.state()
  File "/usr/lib/python2.7/dist-packages/yaml/parser.py", line 428, in parse_block_mapping_key
    if self.check_token(KeyToken):
  File "/usr/lib/python2.7/dist-packages/yaml/scanner.py", line 116, in check_token
    self.fetch_more_tokens()
  File "/usr/lib/python2.7/dist-packages/yaml/scanner.py", line 220, in fetch_more_tokens
    return self.fetch_value()
  File "/usr/lib/python2.7/dist-packages/yaml/scanner.py", line 576, in fetch_value
    self.get_mark())
ScannerError: mapping values are not allowed here
  in "<unicode string>", line 2, column 32:
                        pool_member: 10.30.4.1
                                   ^

fatal: [10.6.177.160]: FAILED! => {
    "msg": "Unexpected failure during module execution.",
    "stdout": ""
}

我有99％的把握是jinja.yaml中的语法错误，但我只是没有解决。任何帮助都会欣赏它。

Answer 1

您正在解决错误的问题；如果您想要list[dict]，则不要尝试使用jinja模板来构建yaml文本，而只是稍后将其转换为所需的实际数据结构：只需构建所需的list[dict]，而无需中间序列化：

- name: XXX
  set_fact:
    members: >-
     {%- set cnt_holder = {"cnt": 0} -%}
     {%- set results = [] -%} 
     {%- for x in range(4, 20) -%}
     {%- for y in range(1, 251) -%}
     {%- set _ = results.append({
        "pool_name": ("pool_%d" | format(cnt_holder.cnt)),
        "pool_member": ("10.30.%d.%d"|format(x, y)),
        }) -%}
     {%- set _ = cnt_holder.update({"cnt": cnt_holder.cnt + 1}) -%}
     {%- endfor -%}
     {%- endfor -%}
     {{ results }}

正如您将看到的那样，您的原始代码块有一个错误：无法重新分配变量（这种情况在for循环之类的词法块中成倍增加）； jinja2的“功能”实际上记录在the fine manual

中

但是，您可以更改现有的数据结构（实际上，这就是results.append的重点）。因此，我们回避了jinja2的set行为，并将可变的cnt存储在全局字典中，以便我们对其进行突变。这就是为什么我的{% set cnt_holder与您的语法不同

与Jinja模板相关的“ ScannerError：此处不允许使用映射值”

1 个答案: