Ansible之roles

1.Roles介绍

ansible自1.2版本引入的新特性,用于层次性、结构化地组织playbook。roles能够根据层次型结构自动装载变量文件、tasks以及handlers等。要使用roles只需要在playbook中使用include指令引入即可。简单来讲,roles就是通过分别将变量、文件、任务、模板及处理器放置于单独的目录中,并可以便捷的include它们的一种机制。角色一般用于基于主机构建服务的场景中,但也可以是用于构建守护进程等场景中。playbook局限在于如果文件较多的情况,不清楚哪些主机执行了哪些状态的yml文件,roles能清楚哪些主机应用哪些角色,主要使用场景代码复用度较高的情况下。

2.Roles目录结构

目录介绍
roles:          <--所有的角色必须放在roles目录下,这个目录可以自定义位置,默认的位置在/etc/ansible/roles
  project:      <---具体的角色项目名称,比如nginx、tomcat、php
    files:     <--用来存放由copy模块或script模块调用的文件。
    templates: <--用来存放jinjia2模板,template模块会自动在此目录中寻找jinjia2模板文件。
    tasks:     <--此目录应当包含一个main.yml文件,用于定义此角色的任务列表,此文件可以使用include包含其它的位于此目录的task文件。
      main.yml
    handlers:  <--此目录应当包含一个main.yml文件,用于定义此角色中触发条件时执行的动作。
      main.yml
    vars:      <--此目录应当包含一个main.yml文件,用于定义此角色用到的变量。
      main.yml
    defaults:  <--此目录应当包含一个main.yml文件,用于为当前角色设定默认变量。
      main.yml
    meta:      <--此目录应当包含一个main.yml文件,用于定义此角色的特殊设定及其依赖关系。
      main.yml

3.ansible roles举例

示例1

#playbook安装tomcat
[root@m01 /project1]# ll
total 202624
-rw-r--r-- 1 root root  12326996 Apr  5 16:45 apache-tomcat-9.0.26.tar.gz
-rwxr-x--- 1 root root     23689 Apr  5 18:08 catalina.sh
-rw-r--r-- 1 root root        17 Apr  4 22:23 hosts
-rw-r--r-- 1 root root 195094741 Apr  5 16:45 jdk-8u221-linux-x64.tar.gz
-rw-r--r-- 1 root root      1617 Apr  5 18:13 server.xml.j2
-rw-r--r-- 1 root root       126 Apr  5 18:08 setenv.sh
-rw-r--r-- 1 root root       290 Apr  5 18:08 tomcat.service
-rw-r--r-- 1 root root      2353 Apr  6 10:54 tomcat.yml
[root@m01 /project1]# vim tomcat.yml
---
- hosts: web
  vars:
    - tomcat_version: 9.0.26
    - jdk_packages: 8u221
    - jdk_version: jdk1.8.0_221
  tasks:
    - name: add group
      group:
        name: www
        gid: 666
        state: present

    - name: add user
      user:
        name: www
        uid: 666
        group: www
        create_home: no
    - name: mkdir directory
      file:
        path: /usr/java
        state: directory

    - name: unarchive jdk-{{ jdk_packages }}-linux-x64.tar.gz
      unarchive:
        src: ./jdk-{{ jdk_packages }}-linux-x64.tar.gz
        dest: /usr/java

    - name: add java environment
      lineinfile:
        path: /etc/profile
        regexp: "{{ item.re }}"
        line: "{{ item.li }}"
      loop:
        - { re: '^export JAVA_HOME=', li: 'export JAVA_HOME=/usr/java/{{ jdk_version }}' }
        - { re: '^export PATH=', li: 'export PATH=$JAVA_HOME/bin:$PATH' }
        - { re: '^export CLASSPATH=', li: 'export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar:$JA
VA_HOME/lib' }

    - name: reloade profile
      shell: source /etc/profile

   - name: unarchive apache-tomcat-{{ tomcat_version }}.tar.gz
      unarchive:
        src: ./apache-tomcat-{{ tomcat_version }}.tar.gz
        dest: /usr/local

    - name: rename tomacat
       shell: cd /usr/local/;mv apache-tomcat-{{tomcat_version}} /usr/local/tomcat;chown -R www.www /usr/local/
tomcat

    - name: copy tomact server rename tomacat
      template:
        src: ./server.xml.j2
        dest: /usr/local/tomcat/conf/server.xml
        backup: yes

    - name: copy file
      copy:
        src: "./{{ item.src }}"
        dest: "{{ item.dest }}"
      loop:
        - { src: 'setenv.sh', dest: '/usr/local/tomcat/bin/' }
        - { src: 'tomcat.service', dest: '/lib/systemd/system/' }
        - { src: 'catalina.sh', dest: '/usr/local/tomcat/bin/' }
      notify: restart tomcat

    - name: ln -s enable
      file:
        src: /lib/systemd/system/tomcat.service
        dest: /etc/systemd/system/multi-user.target.wants/tomcat.service
        state: link

    - name: start tomcat
      systemd:
        daemon_reload: yes
        name: tomcat
        state: started
        enabled: yes

  handlers:
    - name: restart tomcat
      service:
        name: tomcat
        state: restarted              
将playbook改写为rolse
#目录结构
[root@m01 /etc/ansible/roles]# tree tomcat
tomcat
├── files
│   ├── catalina.sh
│   ├── setenv.sh
│   └── tomcat.service
├── handlers
│   └── main.xml
├── tasks
│   └── main.yml
├── templates
│   └── server.xml.j2
└── vars
    └── main.yml
#模块详细类容
1.files
[root@m01 /etc/ansible/roles/tomcat/files]# ll
total 32
-rwxr-x--- 1 root root 23689 Apr  2 21:20 catalina.sh
-rw-r--r-- 1 root root   126 Apr  2 21:23 setenv.sh
-rw-r--r-- 1 root root   290 Apr  2 21:20 tomcat.service
2.tasks
[root@m01 /etc/ansible/roles/tomcat/tasks]# cat main.yml
- name: add group
      group:
        name: www
        gid: 666
        state: present
- name: add user
  user:
     name: www
     uid: 666
     group: www
     create_home: no

- name: mkdir dir
  file:
    path: /usr/java
    state: directory  

- name: unarchive jdk-8u221-linux-x64.tar.gz
  unarchive:
    src: /root/jdk-8u221-linux-x64.tar.gz
    dest: /usr/java

- name: add java environment
  lineinfile:
    path: /etc/profile
    regexp: "{{item.re}}"
    line: "{{item.li}}"
  loop:
    - { re: '^export JAVA_HOME=', li: 'export JAVA_HOME=/usr/java/jdk1.8.0_221' }
    - { re: '^export PATH=', li: 'export PATH=$JAVA_HOME/bin:$PATH' }
    - { re: '^export CLASSPATH=', li: 'export CLASSPATH=$JAVA_HOME/lib/tools.jar:$JAVA_HOME/lib/dt.jar:$JAVA_HOME/lib' }

  
- name: reloade profile
  shell: source /etc/profile


- name: unarchive tomcat-{{tomcat_version}}.tar.gz
  unarchive:
    src: /root/apache-tomcat-{{tomcat_version}}.tar.gz
    dest: /usr/local

- name: rename tomacat
  shell: cd /usr/local/;mv apache-tomcat-{{tomcat_version}} /usr/local/tomcat;chown -R www.www /usr/local/tomcat
 
- name: copy  tomcat server.xml start file
  template:
    src: "{{ item.src }}"
    dest: "{{ item.dest }}"
    backup: yes
  loop:
    - { src: 'server.xml.j2', dest: '/usr/local/tomcat/conf/server.xml' }

- name: copy file
  copy:
    src: "{{ item.src }}"
    dest: "{{ item.dest }}"
  loop:
    - { src: 'setenv.sh', dest: '/usr/local/tomcat/bin/' }
    - { src: 'tomcat.service', dest: '/lib/systemd/system/' }
    - { src: 'catalina.sh', dest: '/usr/local/tomcat/bin/' }

- name: ln -s enable
  file:
    src: /lib/systemd/system/tomcat.service
    dest: /etc/systemd/system/multi-user.target.wants/tomcat.service
    state: link

- name: start tomcat
  systemd:
    daemon_reload: yes
    name: tomcat
    state: started
    enabled: yes
3.template
[root@m01 /etc/ansible/roles/tomcat/templates]# ls
server.xml.j2
4.vars
[root@m01 /etc/ansible/roles/tomcat/vars]# cat main.yml 
tomcat_version: 9.0.26
jdk_packages: 8u221
jdk_version: jdk1.8.0_221
5.handlers
[root@m01 /etc/ansible/roles/tomcat/handlers]# cat main.yml
 - name: restart tomcat
      service:
        name: tomcat
        state: restarted      

示例2
Ansible安装keepalive实现主/备模式高可用

#目录结构
[root@m01 /etc/ansible/roles/keepalived]# ll
total 0
drwxr-xr-x 2 root root 24 Oct 21 20:44 files
drwxr-xr-x 2 root root 22 Apr  6 09:45 handlers
drwxr-xr-x 2 root root 22 Apr  6 10:53 tasks
drwxr-xr-x 2 root root 55 Apr  6 10:29 templates
#rolse详情
1.tasks
[root@m01 /etc/ansible/roles/keepalived/tasks]# vim main.yml
- name: install keepalived server
  yum:
    name: keepalived
    state: present

- name: configure keepalived server
  template:
    src: keepalived.conf.j2
    dest: /etc/keepalived/keepalived.conf
    backup: yes
  notify: restart keepalived

- name: create dir
  file:
    path: /server/scripts/
    state: directory

- name: copy check_web.sh
  template:
    src: check_web.sh.j2
    dest: /server/scripts/check_web.sh
    mode: '0755'

- name: start keepalived server
  systemd:
    name: keepalived
    state: started
    enabled: yes
2.files
[root@m01 /etc/ansible/roles/keepalived/files]# ll
total 4
-rw-r--r-- 1 root root 65 Oct 21 20:44 local.repo
3.templates
[root@m01 /etc/ansible/roles/keepalived/templates]# ls
check_web.sh.j2  keepalived.conf.j2
4.handlers
[root@m01 /etc/ansible/roles/keepalived/handlers]# cat main.yml 
- name: restart keepalived
  systemd:
    name: keepalived
    state: restarted

4.ansible roles总结

1、编写任务(task)的时候,里面不需要写需要执行的主机,单纯的写某个任务是干什么的即可,装软件的就是装软件的,启动的就是启动的。单独做某一件事即可,最后通过main.yml将这些单独的任务安装执行顺序include进来即可,这样方便维护且一目了然。
2、定义变量时候直接安装k:v格式将变量写在vars/main.yml文件即可,然后task或者template直接调用即可,会自动去vars/main.yml文件里面去找。
3、定义handlers时候,直接在handlers/main.yml文件中写需要做什么事情即可,多可的话可以全部写在该文件里面,也可以像task那样分开来写,通过include引入一样的可以。在task调用notify时直接写与handlers名字对应即可(二者必须高度一直)。
4、模板文件一样放在templates目录下即可,task调用的时后直接写文件名字即可,会自动去到templates里面找。
注意:如果是一个角色调用另外一个角色的单个task时后,那么task中如果有些模板或者文件,就得写绝对路径了。

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