如何获得以逗号分隔的名字列表？

Question

这是我在 YAML 文件中的地址列表：

addresses:
  person1:
    firstname: Maria
    lastname:  Smith
  person2:
    firstname: July
    lastname:  Weber
  person3:
    firstname: John
    lastname:  Kurt
  person4:
    firstname: Simon
    lastname:  Gates

我需要的是逗号分隔的字符串，例如 Maria, July, John, Simon

我尝试了以下方法：

firstnames: >-
  {% set lastnames_list= [] %}
  {% for name in addresses %}
      {{ name.firstname | join(",")}}
  {% endfor %}
  {{ lastnames_list }} 

firstnames: >-
  {% set lastnames_list= [] %}
  {% for name in addresses %}
      {{ name | map(attribute="firstname") | join(",") }}
  {% endfor %}
  {{ lastnames_list }} 

firstnames: '{{ addresses | map(attribute="firstname") | join(",") }}'

但是 Ansible 给出了以下输出：

The task includes an option with an undefined variable. The error was: 'unicode object' has no attribute 'firstname'

Answer 1

map 过滤器实际上对一系列对象应用过滤器或查找属性。

但是在这里，您确实有一个字典，既不是对象序列，也不是仅具有属性的对象。

为了实现您正在寻找的东西，有两条路：

如果你坚持使用实际的 YAML 结构，你可以使用 Ansible dict2items 过滤器将你的字典返回到规范化列表中：
```
firstnames: "{{ addresses | dict2items | map(attribute='value') | map(attribute='firstname') | join(',') }}"
```

您可以将您的字典转换为列表，以这种方式更改您的地址列表的结构，然后您的 Jinja 就会工作：

addresses:
  - firstname: Maria
    lastname:  Smith
  - firstname: July
    lastname:  Weber
  - firstname: John
    lastname:  Kurt
  - firstname: Simon
    lastname:  Gates

将与

合作

firstnames: "{{ addresses | map(attribute='firstname') | join(',') }}"

以下是工作示例及其相应的概述。

剧本使用dict2items：

- hosts: local
  gather_facts: no
  vars:
    addresses:
      person1:
        firstname: Maria
        lastname:  Smith
      person2:
        firstname: July
        lastname:  Weber
      person3:
        firstname: John
        lastname:  Kurt
      person4:
        firstname: Simon
        lastname:  Gates

  tasks:
    - debug:
        msg: "{{ addresses | dict2items | map(attribute='value') | map(attribute='firstname') | join(',') }}"

回顾一下：

PLAY [local]    **************************************************************************************************************

TASK [debug]    **************************************************************************************************************
ok: [local] => {
    "msg": "Maria,July,John,Simon"
}

PLAY RECAP    ****************************************************************************************************************
local                      : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

更改 YAML 地址结构的剧本：

- hosts: local
  gather_facts: no
  vars:
    addresses:
      - firstname: Maria
        lastname:  Smith
      - firstname: July
        lastname:  Weber
      - firstname: John
        lastname:  Kurt
      - firstname: Simon
        lastname:  Gates

  tasks:
    - debug:
        msg: "{{ addresses | map(attribute='firstname') | join(',') }}"

回顾一下：

PLAY [local]    **************************************************************************************************************

TASK [debug]    **************************************************************************************************************
ok: [local] => {
    "msg": "Maria,July,John,Simon"
}

PLAY RECAP    ****************************************************************************************************************
local                      : ok=1    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Answer 2

简单json_query filter即可实现结果

- debug:
    msg: '{{ addresses | json_query("@.*.firstname") | join(", ") }}'

给予

ok: [localhost] => 
  msg: Maria, July, John, Simon

如何获得以逗号分隔的名字列表？

How can I get a comma separated list of firstnames?

yaml

jinja2

ansible

ansible-template