Question

Loop循环

标准循环

为了保持简洁,重复的任务可以用以下简写的方式:

- name: add several users
  user: name={{ item }} state=present groups=wheel
  with_items:
     - testuser1
     - testuser2

如果你在变量文件中或者 ‘vars’ 区域定义了一组YAML列表,你也可以这样做:

vars:
  somelist: ["testuser1", "testuser2"]
tasks:
  -name: add several user
   user: name={{ item }} state=present groups=wheel
   with_items: "{{somelist}}"

使用 ‘with_items’ 用于迭代的条目类型不仅仅支持简单的字符串列表.如果你有一个哈希列表,那么你可以用以下方式来引用子项:

- name: add several users
  user: name={{ item.name }} state=present groups={{ item.groups }}
  with_items:
    - { name: 'testuser1', groups: 'wheel' }
    - { name: 'testuser2', groups: 'root' }

注意：如果同时使用 when 和 with_items （或其它循环声明）,when声明会为每个条目单独执行.请参见 the_when_statement 示例.

嵌套循环

循环也可以嵌套:

- name: give users access to multiple databases
  mysql_user: name={{ item[0] }} priv={{ item[1] }}.*:ALL append_privs=yes password=foo
  with_nested:
    - [ 'alice', 'bob' ]
    - [ 'clientdb', 'employeedb', 'providerd']

或者

- name: give users access to multiple databases
  mysql_user: name={{ item.0 }} priv={{ item.1 }}.*:ALL append_privs=yes password=foo
  with_nested:
    - [ 'alice', 'bob' ]
    - [ 'clientdb', 'employeedb', 'providerd']

对哈希表使用循环

---
vars:
  alice:
    name: Alice Appleworth
    telephone: 123-456-7890
  bob:
    name: Bob Bananarama
    telephone: 987-654-3210
tasks:
  - name: Print phone records
    debug: msg="User {{ item.key }} is {{ item.value.name }} ({{ item.value.telephone }})"
    with_dict: "{{users}}"

对文件列表使用循环

with_fileglob 可以以非递归的方式来模式匹配单个目录中的文件.如下面所示:

tasks:

    # first ensure our target directory exists
    - file: dest=/etc/fooapp state=directory

    # copy each file over that matches the given pattern
    - copy: src={{ item }} dest=/etc/fooapp/ owner=root mode=600
      with_fileglob:
        - /playbooks/files/fooapp/*