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如果文件有模式,如何在Ansible中跳过模板副本?

ansible

croceldon · 技术社区 · 4 年前

如果目标文件中没有字符串,则仅尝试复制Nginx配置文件。

我认为这会奏效:

- name: Copy nginx config file
  template:
    src: templates/nginx.conf
    dest: /etc/nginx/sites-enabled/default
    validate: grep -l 'managed by Certbot' %s

但是,如果“由Certbot管理”不在文件中,则此任务会失败,并停止运行剧本。

如果目标文件已经具有该模式,我如何跳过模板复制?也许有更好的方法得到同样的结果?

0 回复 | 直到 4 年前

croceldon 4 年前

灵感来自 this other answer

您可以使用以下命令检查文件中是否存在内容 lineinfile module 在检查模式下。然后,您可以将结果用作模板任务的条件。这个 default 条件是应对文件不存在的情况 found 属性不在注册结果中。

---
- name: Check for presence of "managed by Certbot" in file
  lineinfile:
    path: /etc/nginx/sites-enabled/default
    regexp: ".*# managed by Certbot.*"
    state: absent
  check_mode: yes
  changed_when: false
  register: certbot_managed

- name: Copy nginx config file when not certbot managed
  template:
    src: templates/nginx.conf
    dest: /etc/nginx/sites-enabled/default
  when: certbot_managed.found | default(0) == 0

Î².ÎµÎ·Î¿Î¹Ï.Î²Îµ grigorevp 4 年前

你可以用 failed_when 根据失败消息进行条件和基础设置 validate 生成 failed to validate 采取行动:

- name: Copy nginx config file
  template:
    src: templates/nginx.conf
    dest: /etc/nginx/sites-enabled/default
    validate: grep -l 'managed by Certbot' %s
  failed_when: 
    - copy_config_file.failed
    - copy_config_file.msg != 'failed to validate'
  register: copy_config_file

^{注:in

when

和

*_when

,列出一系列条件就像做

list.0 and list.1 and ...}

根据剧本:

- hosts: all
  gather_facts: no

  tasks:
    - copy:
        dest: templates/nginx.conf
        content: "{{ content | default('some random content') }}"

    - copy:
        dest: /etc/nginx/sites-enabled/default
        content: "blank"

    - template:
        src: templates/nginx.conf
        dest: /etc/nginx/sites-enabled/default
        validate: grep -l 'managed by Certbot' %s
      failed_when: 
        - copy_config_file.failed
        - copy_config_file.msg != 'failed to validate'
      register: copy_config_file

    - shell: cat templates/nginx.conf
      register: template_content
      failed_when: false

    - shell: cat /etc/nginx/sites-enabled/default
      register: file_content
      failed_when: false

    - debug:
        var: template_content.stdout
    
    - debug:
        var: file_content.stdout

当通过运行时:

ansible-playbook play.yml

它给出了:

PLAY [all] *******************************************************************************************************

TASK [copy] ******************************************************************************************************
changed: [localhost]

TASK [copy] ******************************************************************************************************
changed: [localhost]

TASK [template] **************************************************************************************************
ok: [localhost]

TASK [shell] *****************************************************************************************************
changed: [localhost]

TASK [shell] *****************************************************************************************************
changed: [localhost]

TASK [debug] *****************************************************************************************************
ok: [localhost] => {
    "template_content.stdout": "some random content"
}

TASK [debug] *****************************************************************************************************
ok: [localhost] => {
    "file_content.stdout": "blank"
}

PLAY RECAP *******************************************************************************************************
localhost                  : ok=7    changed=4    unreachable=0    failed=0     skipped=0    rescued=0    ignored=0

现在,当跑步时

ansible-playbook play.yml -e "content='managed by Certbot\nsome other content'"

通过一个额外的参数来修改模板的内容,它给出了:

PLAY [all] *******************************************************************************************************

TASK [copy] ******************************************************************************************************
ok: [localhost]

TASK [copy] ******************************************************************************************************
changed: [localhost]

TASK [template] **************************************************************************************************
changed: [localhost]

TASK [shell] *****************************************************************************************************
changed: [localhost]

TASK [shell] *****************************************************************************************************
changed: [localhost]

TASK [debug] *****************************************************************************************************
ok: [localhost] => {
    "template_content.stdout": "managed by Certbot\nsome other content"
}

TASK [debug] *****************************************************************************************************
ok: [localhost] => {
    "file_content.stdout": "managed by Certbot\nsome other content"
}

PLAY RECAP *******************************************************************************************************
localhost                  : ok=7    changed=4    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0