使用 jinja 的 Ansible set_fact 列表

Question

我正在尝试学习 jinja 和 Ansible。这是在 RHEL 7.9 上，

ansible 2.9.27
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /bin/ansible
  python version = 2.7.5 (default, May 27 2022, 11:27:32) [GCC 4.8.5 20150623 (Red Hat 4.8.5-44)]

我进行此练习的唯一原因是学习。但我很困惑。为什么这不会从 found_route_list (这是一个列表)中生成一个列表？

    - name: Populate appended route list
      set_fact:
        found_added_routes: |- 
          {%- set blah = [] %}
            {%- for line in found_route_list %}
              {%- set _ = blah.append(line) %}
            {%- endfor %} 
          {{ blah }}

我的剧本首先收集服务器上的路由:

- name: Get route info
  shell: /usr/sbin/ip route show | sed -e 's/ proto.*//' 
  register: cmdtmp
  changed_when:
    - cmdtmp.stdout | length == 0

- name: Get route list
  set_fact:
    found_route_list: "{{ cmdtmp.stdout.split('\n') }}"

虽然只是产生几行输出，如下所示:

default via 10.13.99.1 dev bond0.99
10.13.101.0/23 dev p1p1.101
128.1.66.227 via 10.13.101.1 dev p1p1.101

我使用 set_fact 对 found_added_routes 执行上述附加操作。然后我调试:

- name: Debug found_route_list
  debug:
    msg: "Found route list: {{ item }}"
  loop: "{{ found_route_list }}"

- name: Debug found_added_routes
  debug:
    msg: "Found: {{ item }}"
  loop: "{{ found_added_routes }}"

这是我的输出:

TASK [networks : Debug found_route_list] **********************************************************************************************************************
ok: [server01.example.com] => (item=default via 10.13.99.1 dev bond0.99) => {
    "msg": "Found route list: default via 10.13.99.1 dev bond0.99"
}
ok: [server01.example.com] => (item=10.13.101.0/24 dev p1p1.101) => {
    "msg": "Found route list: 10.13.101.0/24 dev p1p1.101"
}
ok: [server01.example.com] => (item=128.1.66.227 via 10.13.101.1 dev p1p1.101) => {
    "msg": "Found route list: 128.1.66.227 via 10.13.101.1 dev p1p1.101"
}

TASK [networks : Debug found_added_routes] ********************************************************************************************************************
fatal: [server01.example.com]: FAILED! => {"msg": "Invalid data passed to 'loop', it requires a list, got this instead:  [u'default via 10.13.99.1 dev bond0.99', u'10.13.101.0/24 dev p1p1.101', u'128.1.66.227 via 10.13.101.1 dev p1p1.101']. Hint: If you passed a list/dict of just one element, try adding wantlist=True to your lookup invocation or use q/query instead of lookup."}

我尝试像这样创建列表，但得到相同的输出:

- name: Populate appended route list
  set_fact:
    found_added_routes: "{%- set blah = [] %}
        {%- for line in found_route_list %}
          {%- set _ = blah.append(line) %}
        {%- endfor %} 
      {{ blah }}"

此外，我在 set_fact 中看到了语法，您可以在其中执行以下操作: set_fact: |- 但我一生都找不到任何文档或对其的引用。你能给我指出一些可以解释它的东西吗？

谢谢。

Answer 1

模板的结果始终是字符串。 Quoting :

Jinja can generate any text-based format ...

看一下变量的类型found_added_routes

    - debug:
        var: found_added_routes|type_debug

给出

  found_added_routes|type_debug: str

该字符串是有效的 YAML。使用过滤器 from_yaml 并将字符串转换为列表。例如，

    - debug:
        var: item
      loop: "{{ found_added_routes|from_yaml }}"

给出(删节)

  item: default via 10.13.99.1 dev bond0.99
  item: 10.13.101.0/24 dev p1p1.101
  item: 128.1.66.227 via 10.13.101.1 dev p1p1.101