ansible使用7-Loops

Standard Loops

with_items

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

Nested Loops(with_nested)

- 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', 'providerdb' ]
- name: here, 'users' contains the above list of employees
  mysql_user: name={{ item[0] }} priv={{ item[1] }}.*:ALL append_privs=yes password=foo
  with_nested:
    - users
    - [ 'clientdb', 'employeedb', 'providerdb' ]

Looping over Hashes(with_dict)

---
users:
  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

Looping over Fileglobs(with_fileglob)

---
- hosts: all
  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/*

Looping over Parallel Sets of Data

---
alpha: [ 'a', 'b', 'c', 'd' ]
numbers:  [ 1, 2, 3, 4 ]
tasks:
    - debug: msg="{{ item.0 }} and {{ item.1 }}"
      with_together:
        - alpha
        - numbers
# ('a',1), ('b',2), ('c',3)

Looping over Subelements(with_subelements)

# group_vars/all
---
users:
  - name: alice
    authorized:
      - /tmp/alice/onekey.pub
      - /tmp/alice/twokey.pub
  - name: bob
    authorized:
      - /tmp/bob/id_rsa.pub
- user: name={{ item.name }} state=present generate_ssh_key=yes
  with_items: users
- authorized_key: "user={{ item.0.name }} key='{{ lookup('file', item.1) }}'"
  with_subelements:
     - users
     - authorized

Looping over Integer Sequences(with_sequence)

---
- hosts: all
  tasks:
    # create groups
    - group: name=evens state=present
    - group: name=odds state=present
    # create some test users
    - user: name={{ item }} state=present groups=evens
      with_sequence: start=0 end=32 format=testuser%02x
    # create a series of directories with even numbers for some reason
    - file: dest=/var/stuff/{{ item }} state=directory
      with_sequence: start=4 end=16 stride=2
    # a simpler way to use the sequence plugin
    # create 4 groups
    - group: name=group{{ item }} state=present
      with_sequence: count=4

Random Choices(with_random_choice)

- debug: msg={{ item }}
  with_random_choice:
     - "go through the door"
     - "drink from the goblet"
     - "press the red button"
     - "do nothing"

Do-Until Loops

- action: shell /usr/bin/foo
  register: result
  until: result.stdout.find("all systems go") != -1
  retries: 5
  delay: 10
# retried for 5 times with a delay of 10 seconds

Finding First Matched Files(with_first_found)

- name: INTERFACES | Create Ansible header for /etc/network/interfaces
  template: src={{ item }} dest=/etc/foo.conf
  with_first_found:
    - "{{ansible_virtualization_type}}_foo.conf"
    - "default_foo.conf"
- name: some configuration template
  template: src={{ item }} dest=/etc/file.cfg mode=0444 owner=root group=root
  with_first_found:
    - files:
       - "{{inventory_hostname}}/etc/file.cfg"
      paths:
       - ../../../templates.overwrites
       - ../../../templates
    - files:
        - etc/file.cfg
      paths:
        - templates

Iterating Over The Results of a Program Execution(with_lines)

- name: Example of looping over a command result
  shell: /usr/bin/frobnicate {{ item }}
  with_lines: /usr/bin/frobnications_per_host --param {{ inventory_hostname }}
- name: Example of looping over a REMOTE command result
  shell: /usr/bin/something
  register: command_result
- name: Do something with each result
  shell: /usr/bin/something_else --param {{ item }}
  with_items: command_result.stdout_lines

Looping Over A List With An Index(with_indexed_items)

- name: indexed loop demo
  debug: msg="at array position {{ item.0 }} there is a value {{ item.1 }}"
  with_indexed_items: some_list

Flattening A List

# file: roles/foo/vars/main.yml
packages_base:
  - [ 'foo-package', 'bar-package' ]
packages_apps:
  - [ ['one-package', 'two-package' ]]
  - [ ['red-package'], ['blue-package']]
to 
- name: flattened loop demo
  yum: name={{ item }} state=installed
  with_flattened:
     - packages_base
     - packages_apps

Using register with a loop

- shell: echo "{{ item }}"
  with_items:
    - one
    - two
  register: echo
{
    "changed": true,
    "msg": "All items completed",
    "results": [
        {
            "changed": true,
            "cmd": "echo \"one\" ",
            "delta": "0:00:00.003110",
            "end": "2013-12-19 12:00:05.187153",
            "invocation": {
                "module_args": "echo \"one\"",
                "module_name": "shell"
            },
            "item": "one",
            "rc": 0,
            "start": "2013-12-19 12:00:05.184043",
            "stderr": "",
            "stdout": "one"
        },
        {
            "changed": true,
            "cmd": "echo \"two\" ",
            "delta": "0:00:00.002920",
            "end": "2013-12-19 12:00:05.245502",
            "invocation": {
                "module_args": "echo \"two\"",
                "module_name": "shell"
            },
            "item": "two",
            "rc": 0,
            "start": "2013-12-19 12:00:05.242582",
            "stderr": "",
            "stdout": "two"
        }
    ]
}
- name: Fail if return code is not 0
  fail:
    msg: "The command ({{ item.cmd }}) did not have a 0 return code"
  when: item.rc != 0
  with_items: echo.results