本文將結合例子介紹模塊,條件測試和循環語句的使用
2 模板
模塊和模板的區別,template模塊是將模板文件裏的變量以實際的值重新生成後文件後,複製到遠程主機上
模塊:template
基於模板(以後綴.j2結尾的文件)方式生成一個文件複製到遠程主機,調用ansible的收集到的內建變量,變量的嵌入代碼的標誌是雙花括號
*src=
*dest=
owner=
group=
mode=
模板:templates
文本文件,嵌套有腳本(使用模板編程語言Jinja2編寫)
字面量:
字符串:使用單引號或雙引號;
數字:整數,浮點數;
列表:[item1, item2, ...]
元組:(item1, item2, ...)
字典:{key1:value1, key2:value2, ...}
布爾型:true/false
算術運算:
+, -, *, /, //, %, **
比較操作:
==, !=, >, >=, <, <=
邏輯運算:
and, or, not
例一:
安裝redis軟件,配置redis的配置文件爲模板
修改配置模板文件,以.j2結尾
vim /root/redis.conf.j2
maxmemory {{ ansible_memtotal_mb / 2 }}mb
注意,template不能再命令行執行,即不能在命令裏用-m指定模塊爲template執行,需要定義在腳本里,用playbook執行腳本
vim /root/ansible/installvar.yml
- hosts: websrvs
remote_user: root
vars:- pkgname: redis
tasks: - name: install package
yum: name={{ pkgname }} state=latest - name: install redis conf
template: src=/root/redis.conf.j2 dest=/etc/redis.conf owner=redis group=root mode=644
- pkgname: redis
執行腳本如下
ansible-playbook installvar.yml
則websrvs組裏的主機安裝redis後配置文件配置的maxmemory爲ansible_memtotal_mb / 2 的值
例二:
安裝nginx,把nginx配置文件配置爲模板
vim /root/ansible/instnginx.yml
- hosts: websrvs
remote_user: root
tasks: - name: install nginx
yum: name=nginx state=present - name: install conf file
template: src=/root/nginx.conf.j2 dest=/etc/nginx/nginx.conf
notify: restart nginx
tags: instconf - name: start nginx service
service: name=nginx state=started
handlers: - name: restart nginx
service: name=nginx state=restarted
模板配置文件 :nginx.conf.j2
worker_processes {{ ansible_processor_vcpus }};
server_name {{ ansible_fqdn }};
3 條件測試
如被管控的主機系統不一樣,執行的語句可能會不一樣,需要做條件的判定
when語句:在task中使用,jinja2的語法格式
例子:
在centos6和centos7上安裝nginx,判斷對應主機系統版本,實現不一樣的配置
vim instnginx.yml
- hosts: nginx
remote_user: root
tasks:- name: install nginx package
yum: name=nginx state=latest
tags: instpkg - name: install conf file6
template: src=/root/nginx.conf.c6.j2 dest=/etc/nginx/nginx.conf
when: ansible_distribution_major_version == "6"
notify: restart nginx - name: install conf file7
template: src=/root/nginx.conf.c7.j2 dest=/etc/nginx/nginx.conf
when: ansible_distribution_major_version == "7"
notify: restart nginx - name: start nginx service
service: name=nginx enabled=true state=started
handlers: - name: restart nginx
service: name=nginx state=restarted
- name: install nginx package
運行
1
ansible-playbook instnginx.yml
例子:
根據主機的ip,拷貝不同的文件到對應的主機
vim cpfile.yml
- hosts: nginx
remote_user: root
tasks:- name: copy file6
copy: src=/root/nginx.conf.c6.j2 dest=/tmp/
when: ansible_default_ipv4['address'] == '172.18.50.63' - name: copy file7
copy: src=/root/nginx.conf.c7.j2 dest=/tmp/
when: ansible_default_ipv4['address'] == '172.18.50.75'
- name: copy file6
執行
1
ansible-playbook cpfile.yml
4 循環
迭代,需要重複執行的任務;
1 對迭代項的引用,固定變量名爲”item“
2 然後在task中使用with_items給定要迭代的元素列表;
列表方法:
字符串
字典:元素可以是字典,複製多個文件時,可以直接使用copy模塊
例子:
通過迭代的方法安裝服務包和創建用戶
vim iteration.yml
- hosts: dbsrvs
remote_user: root
vars:- jdk_version: 1.8.0
tasks: - name: install {{ item }} package
yum: name={{ item.name }}-{{ item.version }} state=latest
with_items: - { name: 'nginx',version: '1.10.2' }
- { name: 'tree',version: '1.5.3' }
- name: copy nginx conf
copy: src={{ item.file }} dest={{ item.conf }}
with_items: - { file: '/root/nginx.conf.os6',conf: '/etc/nginx.conf' }
- name: install {{ item }} package
yum: name={{ item }} state=latest
with_items: - java-{{ jdk_version }}-openjdk
- tomcat
- tomcat-webapps
- tomcat-docs-webapp
- tomcat-admin-webapps
- name: add some groups
group: name={{ item }} state=present
with_items: - ansigrp1
- ansigrp2
- name: add some users
user: name={{ item.name }} group={{ item.group }} state=present
with_items: - { name: 'ansiuser1', group: 'ansigrp1' }
- { name: 'ansiuser2', group: 'ansigrp2' }
- jdk_version: 1.8.0