Nginx 无法通过 Ansible 重新启动

我在剧本中有一个任务，尝试像往常一样通过处理程序重新启动 nginx：

- name: run migrations
  command: bash -lc "some command"
  notify: restart nginx

然而，剧本因这个错误而中断：

NOTIFIED: [deploy | restart nginx] ******************************************** 
failed: [REDACTED] => {"failed": true}
msg: failure 1 running systemctl show for 'nginx.service': Failed to get D-Bus connection: No connection to service manager.

处理程序是标准的：

- name: restart nginx
  service: name=nginx state=restarted enabled=yes

我设置 nginx 的方式也很平常：

- name: install nginx
  apt: name=nginx state=present
  sudo: yes

- name: copy nginx.conf to the server
  template: src=nginx.conf.j2 dest=/etc/nginx/nginx.conf
  sudo: yes

- name: delete default virtualhost
  file: path=/etc/nginx/sites-enabled/default state=absent
  sudo: yes

- name: add mysite site-available
  template: src=mysite.conf.j2 dest=/etc/nginx/sites-available/mysite.conf
  sudo: yes

- name: link mysite site-enabled
  file: path=/etc/nginx/sites-enabled/mysite src=/etc/nginx/sites-available/mysite.conf state=link
  sudo: yes

这是在一个ubuntu-14-04-x64 VPS.

处理程序是：

- name: restart nginx
  service: name=nginx state=restarted enabled=yes

看来状态和启用标志不能同时存在。通过将上面的内容修剪为以下内容，它起作用了。

- name: restart nginx
  service: name=nginx state=restarted

我不知道为什么会这样，为什么它突然开始破裂。