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Accepted
dutsnekcirf
Asked: 2022-02-01 15:57:41 +0800 CST

使用 Jinja2 模板遍历嵌套列表/字典

  • 772

我正在尝试通过使用 Ansible 生成 /etc/exports 文件来动态配置系统中的多个 NFS 服务器。我希望能够使用 jinja2 模板来做到这一点。这是我根据导出列表无法确定的 jinja2 模板。

我在我的 nfs 角色中定义了以下变量：

site_nfs_servers: ['ansibletarget1', 'ansibletarget2']

exports:
  - server: "ansibletarget1"
    shares:
      - path: "/my/first/share/path"
        client: "*"
        options: "rw,sync"
      - path: "/my/second/share/path"
        client: "*"
        options: "rw,sync,root_squash"
  - server: "ansibletarget2"
    shares:
      - path: "/another/shared/path/different/server"
        client: "*"
        options: "ro,sync"

然后我有以下 ansible play 来生成模板：

- name: Generate the exports file.
  template:
    src: exports.j2
    dest: /etc/exports
    owner: root
    group: root
    mode: '0750'

我的模板目前看起来像这样：

{% for export in exports %}
{% if ansible_hostname in export.server %}
{% for share in shares %}
{{ share.path }} {{ share.client }} {{ share.options }}
{% endfor %}
{% endif %}
{% endfor %}

我认为我离正确的模板结构还差得很远。到底是如何遍历这个列表的？

ansible ansible-playbook jinja2

2 个回答

  1. export您在第二个循环中缺少对 the 的引用。

    {% for export in exports %}
{% if ansible_hostname in export.server %}
{% for share in export.shares %}
{{ share.path }} {{ share.client }} {{ share.options }}
{% endfor %}
{% endif %}
{% endfor %}

    但是，最好在主机变量中定义共享，如 Vladimir 的回答所示。

    • 3
  2. Best Answer

    创建库存

    shell> cat hosts
[site_nfs_servers]
ansibletarget1
ansibletarget2

    并将股份放入host_vars

    shell> cat host_vars/ansibletarget1.yml 
shares:
  - path: "/my/first/share/path"
    client: "*"
    options: "rw,sync"
  - path: "/my/second/share/path"
    client: "*"
    options: "rw,sync,root_squash"

    shell> cat host_vars/ansibletarget2.yml 
shares:
  - path: "/another/shared/path/different/server"
    client: "*"
    options: "ro,sync"

    为测试创建一个简化的角色

    shell> tree roles/my_nfs_role/
roles/my_nfs_role/
├── tasks
│   └── main.yml
└── templates
    └── exports.j2

2 directories, 2 files

    shell> cat roles/my_nfs_role/tasks/main.yml 
- template:
    src: exports.j2
    dest: /etc/exports.test

    shell> cat roles/my_nfs_role/templates/exports.j2 
{% for share in shares %}
{{ share.path }} {{ share.client }} {{ share.options }}
{% endfor %}

    然后，使用清单组和剧本中的角色

    shell> cat playbook.yml
- hosts: site_nfs_servers
  roles:
    - my_nfs_role

    运行剧本并创建文件

    shell> ansible-playbook -i hosts playbook.yml

PLAY [site_nfs_servers] ************************************************

TASK [my_nfs_role : template] ******************************************
changed: [ansibletarget1]
changed: [ansibletarget2]
 ...

    shell> ssh admin@ansibletarget1 cat /etc/exports.test
/my/first/share/path * rw,sync
/my/second/share/path * rw,sync,root_squash

shell> ssh admin@ansibletarget2 cat /etc/exports.test
/another/shared/path/different/server * ro,sync

    请参阅示例 Ansible 设置。

    如果您想将共享保留在一个对象中，请将列表放入groups_vars中。为了简化代码，将列表转换为字典。例如，您可以使用community.general.groupby_as_dict

    shell> cat group_vars/all.yml
exports:
  - server: "ansibletarget1"
    shares:
      - path: "/my/first/share/path"
        client: "*"
        options: "rw,sync"
      - path: "/my/second/share/path"
        client: "*"
        options: "rw,sync,root_squash"
  - server: "ansibletarget2"
    shares:
      - path: "/another/shared/path/different/server"
        client: "*"
        options: "ro,sync"

exports_dict: "{{ exports|community.general.groupby_as_dict('server') }}"

    给

      exports_dict:
    ansibletarget1:
      server: ansibletarget1
      shares:
      - client: '*'
        options: rw,sync
        path: /my/first/share/path
      - client: '*'
        options: rw,sync,root_squash
        path: /my/second/share/path
    ansibletarget2:
      server: ansibletarget2
      shares:
      - client: '*'
        options: ro,sync
        path: /another/shared/path/different/server

    然后修改模板。这应该创建与以前相同的文件。

    shell> cat roles/my_nfs_role/templates/exports.j2 
{% for share in exports_dict[inventory_hostname]['shares'] %}
{{ share.path }} {{ share.client }} {{ share.options }}
{% endfor %}
    • 2

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