條件判斷
When 語句
在when 後面使用Jinja2 表達式，結果爲True則執行任務。javascript
tasks:
- name: "shut down Debian flavored systems" command: /sbin/shutdown -t now when: ansible_os_family == "Debian"
若操做系統是Debian 時就執行關機操做php
能夠對條件進行分組在比較。java
tasks:
- name: "shut down CentOS 6 and Debian 7 systems" command: /sbin/shutdown -t now when: (ansible_distribution == "CentOS" and ansible_distribution_major_version == "6") or (ansible_distribution == "Debian" and ansible_distribution_major_version == "7")
能夠使用列表形式來表示條件爲and的關係python
tasks:
- name: "shut down CentOS 6 systems" command: /sbin/shutdown -t now when: - ansible_distribution == "CentOS" - ansible_distribution_major_version == "6"
使用jinja2過濾器mysql
tasks:
- command: /bin/false register: result ignore_errors: True - command: /bin/something when: result|failed - command: /bin/something_else when: result|succeeded - command: /bin/still/something_else when: result|skipped
忽略一個語句的錯誤，而後決定基於成功或失敗有條件地作一些事情。web
字符串轉換爲數字型再去比較sql
tasks:
- shell: echo "only on Red Hat 6, derivatives, and later" when: ansible_os_family == "RedHat" and ansible_lsb.major_release|int >= 6
使用變量進行判斷shell
vars:
epic: true tasks: - shell: echo "This certainly is epic!" when: epic tasks: - shell: echo "This certainly isn't epic!" when: not epic
判斷變量是否認義數據庫
tasks:
- shell: echo "I've got '{{ foo }}' and am not afraid to use it!" when: foo is defined - fail: msg="Bailing out. this play requires 'bar'" when: bar is undefined
與循環一塊兒使用ruby
tasks:
- command: echo {{ item }} with_items: [ 0, 2, 4, 6, 8, 10 ] when: item > 5
依次遍歷列表，當列表裏得數字大於5時執行任務
- command: echo {{ item }} with_items: "{{ mylist|default([]) }}" when: item > 5 - command: echo {{ item.key }} with_dict: "{{ mydict|default({}) }}" when: item.value > 5
當變量不存在時，直接跳過
使用自定義的facts值作判斷
tasks:
- name: gather site specific fact data
action: site_facts
- command: /usr/bin/thingy when: my_custom_fact_just_retrieved_from_the_remote_system == '1234'
角色包含使用when
- include: tasks/sometasks.yml when: "'reticulating splines' in output" - hosts: webservers roles: - { role: debian_stock_config, when: ansible_os_family == 'Debian' }
基於變量選擇文件和模板
- name: template a file template: src={{ item }} dest=/etc/myapp/foo.conf with_first_found: - files: - {{ ansible_distribution }}.conf - default.conf paths: - search_location_one/somedir/ - /opt/other_location/somedir/
使用註冊變量判斷
- name: test play hosts: all tasks: - shell: cat /etc/motd register: motd_contents - shell: echo "motd contains the word hi" when: motd_contents.stdout.find('hi') != -1
failed_when
知足條件時，使任務失敗
tasks:
- command: echo faild. register: command_result failed_when: "'faild' in command_result.stdout" - debug: msg="echo test"
還能夠寫成這樣
tasks:
- command: echo faild. register: command_result ignore_errors: True - name: fail the echo fail: msg="the command failed" when: "'faild' in command_result.stdout" - debug: msg="echo test"
changed_when
更改任務的狀態。
- name: Install dependencies via Composer.
command: "/usr/local/bin/composer global require phpunit/phpunit --prefer-dist" register: composer changed_when: "'Nothing to install or update' not in composer.stdout"
當使用PHP Composer做爲安裝項目依賴項的命令時，知道何時是有用的Composer安裝了一些東西，或什麼都沒有改變。
循環
標準循環
添加多個用戶
- name: add several users
user: name={{ item }} state=present groups=wheel
with_items:
- testuser1
- testuser2
添加多個用戶，並將用戶加入不一樣的組內。
- name: add several users
user: name={{ item.name }} state=present groups={{ item.groups }}
with_items:
- { name: 'testuser1', groups: 'wheel' } - { name: 'testuser2', groups: 'root' }
嵌套循環
分別給用戶授予3個數據庫的全部權限
- 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' ]
遍歷字典
輸出用戶的姓名和電話
tasks:
- name: Print phone records debug: msg="User {{ item.key }} is {{ item.value.name }} ({{ item.value.telephone }})" with_dict: {'alice':{'name':'Alice Appleworth', 'telephone':'123-456-789'},'bob':{'name':'Bob Bananarama', 'telephone':'987-654-3210'} }
並行遍歷列表
tasks:
- debug: "msg={{ item.0 }} and {{ item.1 }}" with_together: - [ 'a', 'b', 'c', 'd','e' ] - [ 1, 2, 3, 4 ]
若是列表數目不匹配，用None補全
遍歷列表和索引
- name: indexed loop demo
debug: "msg='at array position {{ item.0 }} there is a value {{ item.1 }}'" with_indexed_items: [1,2,3,4]
item.0 爲索引，item.1爲值
遍歷文件列表的內容
---
- hosts: all
tasks:
- debug: "msg={{ item }}" with_file: - first_example_file - second_example_file
遍歷目錄文件
with_fileglob匹配單個目錄中的全部文件，非遞歸匹配模式。
---
- hosts: all
tasks:
- file: dest=/etc/fooapp state=directory - copy: src={{ item }} dest=/etc/fooapp/ owner=root mode=600 with_fileglob: - /playbooks/files/fooapp/*
當在role中使用with_fileglob的相對路徑時，Ansible解析相對於roles/<rolename>/files目錄的路徑。
遍歷ini文件
lookup.ini [section1] value1=section1/value1 value2=section1/value2 [section2] value1=section2/value1 value2=section2/value2
- debug: msg="{{ item }}" with_ini: value[1-2] section=section1 file=lookup.ini re=true
獲取section1 裏的value1和value2的值
重試循環 until
- action: shell /usr/bin/foo
register: result until: result.stdout.find("all systems go") != -1 retries: 5 delay: 10
"重試次數retries" 的默認值爲3，"delay"爲5。
查找第一個匹配文件
tasks:
- debug: "msg={{ item }}" with_first_found: - "/tmp/a" - "/tmp/b" - "/tmp/default.conf"
依次尋找列表中的文件，找到就返回。若是列表中的文件都找不到，任務會報錯。
隨機選擇with_random_choice
隨機選擇列表中得一個值
- debug: msg={{ item }}
with_random_choice:
- "go through the door" - "drink from the goblet" - "press the red button" - "do nothing"
循環程序的結果
tasks:
- debug: "msg={{ item }}" with_lines: ps aux
循環子元素
定義好變量
#varfile --- users: - name: alice authorized: - /tmp/alice/onekey.pub - /tmp/alice/twokey.pub mysql: password: mysql-password hosts: - "%" - "127.0.0.1" - "::1" - "localhost" privs: - "*.*:SELECT" - "DB1.*:ALL" - name: bob authorized: - /tmp/bob/id_rsa.pub mysql: password: other-mysql-password hosts: - "db1" privs: - "*.*:SELECT" - "DB2.*:ALL"
---
- hosts: web
vars_files: varfile
tasks:
- 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 - name: Setup MySQL users mysql_user: name={{ item.0.name }} password={{ item.0.mysql.password }} host={{ item.1 }} priv={{ item.0.mysql.privs | join('/') }} with_subelements: - "{{ users }}" - mysql.hosts
{{ lookup('file', item.1) }} 是查看item.1文件的內容
with_subelements 遍歷哈希列表，而後遍歷列表中的給定（嵌套）的鍵。
在序列中循環with_sequence
with_sequence以遞增的數字順序生成項序列。 您能夠指定開始，結束和可選步驟值。
參數應在key = value對中指定。 'format'是一個printf風格字符串。
數字值能夠以十進制，十六進制（0x3f8）或八進制（0600）指定。 不支持負數。
---
- hosts: all
tasks:
# 建立組 - group: name=evens state=present - group: name=odds state=present # 建立格式爲testuser%02x 的0-32 序列的用戶 - user: name={{ item }} state=present groups=evens with_sequence: start=0 end=32 format=testuser%02x # 建立4-16之間得偶數命名的文件 - file: dest=/var/stuff/{{ item }} state=directory with_sequence: start=4 end=16 stride=2 # 簡單實用序列的方法：建立4 個用戶組分表是組group1 group2 group3 group4 - group: name=group{{ item }} state=present with_sequence: count=4
隨機選擇with_random_choice
隨機選擇列表中得一個值
- debug: msg={{ item }}
with_random_choice:
- "go through the door" - "drink from the goblet" - "press the red button" - "do nothing"
合併列表
# 安裝全部列表中的軟件 - name: flattened loop demo yum: name={{ item }} state=installed with_flattened: - [ 'foo-package', 'bar-package' ] - [ ['one-package', 'two-package' ]] - [ ['red-package'], ['blue-package']]
註冊變量使用循環
- shell: echo "{{ item }}" with_items: - one - two register: echo - 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 }}"
循環主機清單
# 輸出全部主機清單裏的主機 - debug: msg={{ item }} with_items: "{{ groups['all'] }}" # 輸出全部執行的主機 - debug: msg={{ item }} with_items: play_hosts #輸出全部主機清單裏的主機 - debug: msg={{ item }} with_inventory_hostnames: all # 輸出主機清單中不在www中的全部主機 - debug: msg={{ item }} with_inventory_hostnames: all:!www
改變循環的變量項
# main.yml - include: inner.yml with_items: - 1 - 2 - 3 loop_control: loop_var: outer_item # inner.yml - debug: msg="outer item={{ outer_item }} inner item={{ item }}" with_items: - a - b - c