ansible使用5-Variables

变量命名

支持数字、字母、下划线

有效：foo_port, foo5

无效：foo-port, foo port, foo.port, 12

playbook定义

- hosts: webservers

  vars:

    http_port: 80

jinja2模板使用变量

My amp goes to {{ max_amp_value }}

template: src=foo.cfg.j2 dest={{ remote_install_path }}/foo.cfg

Jinja2 Filters

格式化数据

{{ some_variable | to_nice_json }}

{{ some_variable | to_nice_yaml }}

使用条件表达式

tasks:

  - shell: /usr/bin/foo

    register: result

    ignore_errors: True

  - debug: msg="it failed"

    when: result|failed

  # in most cases you'll want a handler, but if you want to do something right now, this is nice

  - debug: msg="it changed"

    when: result|changed

  - debug: msg="it succeeded"

    when: result|success

  - debug: msg="it was skipped"

    when: result|skipped

强制变量定义

{{ variable | mandatory }}

变量默认值

{{ some_variable | default(5) }}

变量省略值

- name: touch files with an optional mode

  file: dest={{item.path}} state=touch mode={{item.mode|default(omit)}}

  with_items:

    - path: /tmp/foo

    - path: /tmp/bar

    - path: /tmp/baz

      mode: "0444"

列表

# 最小值

{{ list1 | min }}

# 最大值

{{ [3, 4, 2] | max }}

# 唯一值

{{ list1 | unique }}

# 并集

{{ list1 | union(list2) }}

# 交集

{{ list1 | intersect(list2) }}

# 补集（存在list1,不存在list2）

{{ list1 | difference(list2) }}

# 对称差集 (不同时存在每个列表)

{{ list1 | symmetric_difference(list2) }}

版本比较

{{ ansible_distribution_version | version_compare('12.04', '>=') }}

# <, lt, <=, le, >, gt, >=, ge, ==, =, eq, !=, <>, ne

# 版本分析strict=True，默认值false

随机数

{{ ['a','b','c']|random }} => 'c'

{{ 59 |random}} * * * * root /script/from/cron

{{ 100 |random(step=10) }}  => 70

{{ 100 |random(1, 10) }}    => 31

{{ 100 |random(start=1, step=10) }}    => 51

洗牌(shuffle)

{{ ['a','b','c']|shuffle }} => ['c','a','b']

{{ ['a','b','c']|shuffle }} => ['b','c','a']

其他

# 列表转字符串

{{ list | join(" ") }}

# 文件全路径

{{ path | basename }}

# 目录全路径

{{ path | dirname }}

# 用户目录（～）全路径

{{ path | expanduser }}

#　link的路径

{{ path | readlink }}

#　Base64加解密

{{ encoded | b64decode }}

{{ decoded | b64encode }}

# 文件的sha1sum

{{ filename | sha1 }}

bool

- debug: msg=test

  when: some_string_value | bool

正则

vars:

  url: "http://example.com/users/foo/resources/bar"

tasks:

    - shell: "msg='matched pattern 1'"

      when: url | match("http://example.com/users/.*/resources/.*")

    - debug: "msg='matched pattern 2'"

      when: url | search("/users/.*/resources/.*")

# convert "ansible" to "able"

{{ 'ansible' | regex_replace('^a.*i(.*)$', 'a\\1') }}

# convert "foobar" to "bar"

{{ 'foobar' | regex_replace('^f.*o(.*)$', '\\1') }}

- hosts: app_servers

  vars:

       app_path: "{{ base_path }}/22"

Facts

'''bash

ansible hostname -m setup

{{ ansible_devices.sda.model }}

{{ ansible_hostname }}

'''

Turning Off Facts

- hosts: whatever

  gather_facts: no

本地facts(自定义facts)

# /etc/ansible/facts.d/preferences.fact

[general]

asdf=1

bar=2

# 命令

ansible <hostname> -m setup -a "filter=ansible_local"

# API

"ansible_local": {

        "preferences": {

            "general": {

                "asdf" : "1",

                "bar"  : "2"

            }

        }

 }

# 引用

{{ ansible_local.preferences.general.asdf }}

# 部署

- hosts: webservers

  tasks:

    - name: create directory for ansible custom facts

      file: state=directory recurse=yes path=/etc/ansible/facts.d

    - name: install custom impi fact

      copy: src=ipmi.fact dest=/etc/ansible/facts.d

    - name: re-read facts after adding custom fact

      setup: filter=ansible_local

Fact Caching

{{ hostvars['asdf.example.com']['ansible_os_family'] }}

# /etc/ansible/ansible.cfg

[defaults]

fact_caching = redis

fact_caching_timeout = 86400

# seconds

yum install redis

service redis start

pip install redis

Registered Variables

- hosts: web_servers

  tasks:

     - shell: /usr/bin/foo

       register: foo_result

       ignore_errors: True

     - shell: /usr/bin/bar

       when: foo_result.rc == 5

Accessing Complex Variable Data

{{ ansible_eth0["ipv4"]["address"] }}

{{ ansible_eth0.ipv4.address }}

{{ foo[0] }}

Magic Variables, and How To Access Information About Other Hosts

{{ hostvars['test.example.com']['ansible_distribution'] }}

{% if 'webserver' in group_names %}

   # some part of a configuration file that only applies to webservers

{% endif %}

{% for host in groups['app_servers'] %}

   # something that applies to all app servers.

{% endfor %}

# example

{% for host in groups['app_servers'] %}

   {{ hostvars[host]['ansible_eth0']['ipv4']['address'] }}

{% endfor %}

Variable File Separation

---

- hosts: all

  remote_user: root

  vars:

    favcolor: blue

  vars_files:

    - /vars/external_vars.yml

  tasks:

  - name: this is just a placeholder

    command: /bin/echo foo

---

# in the above example, this would be vars/external_vars.yml

somevar: somevalue

password: magic

Passing Variables On The Command Line

ansible-playbook release.yml --extra-vars "version=1.23.45 other_variable=foo"

#example

---

- hosts: '{{ hosts }}'

  remote_user: '{{ user }}'

  tasks:

     - ...

ansible-playbook release.yml --extra-vars "hosts=vipers user=starbuck"

or

--extra-vars '{"pacman":"mrs","ghosts":["inky","pinky","clyde","sue"]}'

or

--extra-vars "@some_file.json"

Variable Precedence: Where Should I Put A Variable?

#组变量默认值在group_vars/all

---

# file: /etc/ansible/group_vars/all

# this is the site wide default

ntp_server: default-time.example.com

# 组变量，覆盖组默认变量

---

# file: /etc/ansible/group_vars/boston

ntp_server: boston-time.example.com

# 主机变量，覆盖组变量

---

# file: /etc/ansible/host_vars/xyz.boston.example.com

ntp_server: override.example.com

role variable precedence

---

# file: roles/x/defaults/main.yml

# if not overridden in inventory or as a parameter, this is the value that will be used

http_port: 80

# 不能覆盖默认值

---

# file: roles/x/vars/main.yml

# this will absolutely be used in this role

http_port: 80

# 使用这种方式覆盖默认值

roles:

   - { name: apache, http_port: 8080 }

roles:

   - { role: app_user, name: Ian    }

   - { role: app_user, name: Terry  }

   - { role: app_user, name: Graham }

   - { role: app_user, name: John   }

# roles/common/vars/main.yml

roles:

   - { role: common_settings }

   - { role: something, foo: 12 }

   - { role: something_else }

巴特西

ansible使用5-Variables

变量命名

playbook定义

jinja2模板使用变量

Jinja2 Filters

版本比较

随机数

洗牌(shuffle)

其他

Facts

Turning Off Facts

本地facts(自定义facts)

Fact Caching

Registered Variables

Accessing Complex Variable Data

Magic Variables, and How To Access Information About Other Hosts

Variable File Separation

Passing Variables On The Command Line

Variable Precedence: Where Should I Put A Variable?

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