ansible - 如何在 vars 中使用注册的 ansible 变量的字典？

Question

我想使用 vars 将多个变量传递给任务。目前，我正在这样做

vars:
    var1_name: "var1_value"
    var2_name: "var2_value"

随着变量数量的增加，我宁愿使用 vars 将变量字典传递给任务。我构建了一个变量字典，如下所示

- name: set fact
  hosts: localhost
  tasks:
  - set_fact:
      variables: "{{ variables|default({}) | combine( {item.variable: item.value} ) }}"
    with_items:
    - variable: var1_name
      value: "var1_value"
    - variable: var2_name
      value: "var2_name"

字典看起来像这样:

"variables": {
    "var1_name": "var1_value",
    "var2_name": "var2_value",
}

现在，我想让该字典中的变量可供在其他主机上执行的角色使用。

但是，当我尝试将字典传递给 vars 时，如下所示

vars: "{{ variables }}"

Ansible 抛出错误:

ERROR! Vars in a Play must be specified as a dictionary, or a list of dictionaries

如何在vars中传递字典变量？

Answer 1

在对 Ansible 源代码进行一些搜索后，看起来这甚至是 Ansible 开发人员也面临的问题。在某些集成测试中，有一些特定的测试由于同样的错误而被注释掉。

https://github.com/ansible/ansible/blob/devel/test/integration/targets/include_import/role/test_include_role.yml#L96

## FIXME Currently failing with
## ERROR! Vars in a IncludeRole must be specified as a dictionary, or a list of dictionaries
# - name: Pass all variables in a variable to role
#   include_role:
#     name: role1
#     tasks_from: vartest.yml
#   vars: "{{ role_vars }}"

我还发现这是被调用以包含变量的底层函数:

https://github.com/ansible/ansible/blob/devel/lib/ansible/playbook/base.py#L681

    def _load_vars(self, attr, ds):
        '''
        Vars in a play can be specified either as a dictionary directly, or
        as a list of dictionaries. If the later, this method will turn the
        list into a single dictionary.
        '''

        def _validate_variable_keys(ds):
            for key in ds:
                if not isidentifier(key):
                    raise TypeError("'%s' is not a valid variable name" % key)

        try:
            if isinstance(ds, dict):
                _validate_variable_keys(ds)
                return combine_vars(self.vars, ds)
            elif isinstance(ds, list):
                all_vars = self.vars
                for item in ds:
                    if not isinstance(item, dict):
                        raise ValueError
                    _validate_variable_keys(item)
                    all_vars = combine_vars(all_vars, item)
                return all_vars
            elif ds is None:
                return {}
            else:
                raise ValueError
        except ValueError as e:
            raise AnsibleParserError("Vars in a %s must be specified as a dictionary, or a list of dictionaries" % self.__class__.__name__,
                                     obj=ds, orig_exc=e)
        except TypeError as e:
            raise AnsibleParserError("Invalid variable name in vars specified for %s: %s" % (self.__class__.__name__, e), obj=ds, orig_exc=e)

似乎由于“{{ }}”实际上只是一个 YAML 字符串，Ansible 不会将其识别为字典，这意味着 vars 属性没有通过 Jinja2 引擎传递，而是被评估为什么确实如此。

传递 YAML 对象的唯一方法是使用 anchor ，但这需要整个对象定义而不是动态定义。

    var: &_anchored_var 
      attr1: "test"
      att2: "bar"
    
    vars:
      <<: *_anchored_var