ansible - roles roles

I. Overview

1.roles role introduction

Roles are used to organize playbooks hierarchically and structurally. Roles can automatically load variable files, tasks, handlers, etc. according to the hierarchical structure. To use roles, you only need to use the include directive in the playbook to introduce them.
Simply put, roles are a mechanism that places variables, files, tasks, templates, and processors in separate directories and can easily include them. Roles are generally used in scenarios where services are built based on hosts, but they can also be used in scenarios such as building daemons. Mainly used in scenarios where code reuse is high.

2.roles The role of roles

Treat each play in the playbook as a role, and combine the tasks, vars variables, templates, and files of each role

3. Explanation of the meaning of each directory within roles

• files: used to store files called by the copy module or script module.
• templates: used to store jinjia2 templates. The template module will automatically search for jinjia2 template files in this directory.
• tasks: This directory should contain a main.yml file to define the task list of this role. This file can use include to include other task files located in this directory.
• handlers: This directory should contain a main.yml file that defines the actions to be performed when a condition is triggered in this role.
• vars: This directory should contain a main.yml file that defines the variables used by this role.
• defaults: This directory should contain a main.yml file to set default variables for the current role. These variables have the lowest priority of all available variables and can be easily overridden by any other variable. Therefore, we generally do not define variables here in production.
• meta: This directory should contain a main.yml file that defines the metadata information of this role and its dependencies.

2. Create lnmp using roles in playbook

1. Preparation

1.1Create a directory named after roles

mkdir /etc/ansible/roles/ -p    #yum装完默认就有

1.2 Create directories named after each role in the roles directory.

mkdir /etc/ansible/roles/nginx
mkdir /etc/ansible/roles/mysql
mkdir /etc/ansible/roles/php

1.3 Create files, handlers, tasks, templates, meta, defaults and vars directories in the directory named by each role. Unused directories can be created as empty directories or not created at all.

mkdir /etc/ansible/roles/nginx/{files,templates,tasks,handlers,vars,defaults,meta}
mkdir /etc/ansible/roles/mysql/{files,templates,tasks,handlers,vars,defaults,meta}
mkdir /etc/ansible/roles/php/{files,templates,tasks,handlers,vars,defaults,meta}

1.4 Create the main.yml file in the handlers, tasks, meta, defaults, and vars directories of each role. Do not customize the file name.

touch /etc/ansible/roles/nginx/{defaults,vars,tasks,meta,handlers}/main.yml
touch /etc/ansible/roles/mysql/{defaults,vars,tasks,meta,handlers}/main.yml
touch /etc/ansible/roles/php/{defaults,vars,tasks,meta,handlers}/main.yml

2. Use roles to create nginx

2.1 Edit nginx tasks

cd /etc/ansible/roles/nginx/tasks
vim main.yml
#引用该目录下的init.yml
- include: init.yml

- name: nginx.repo
  copy: src=nginx.repo dest=/etc/yum.repos.d/

- name: install nginx
  yum: name={
   
   {pkg}} state=latest

- name: nginx congrustion file
  template: src=default.conf.j2 dest=/etc/nginx/conf.d/default.conf
  notify: "reload nginx"         #以上操作后为changed的状态时，会通过notify指定的名称触发对应名称的handlers操作

- name: index.php
  copy: src=index.php dest={
   
   {root_dir}}

- name: start nginx
  service: name={
   
   {svc}} state=started enabled=yes

#编写关闭防火墙任务
vim init.yml
- name: disable firewalld
  service: name=firewalld state=started enabled=no

- name: stop selinux
  shell: "/usr/sbin/setenforce 0"
  ignore_errors: true

2.2 Define actions to be performed when triggering conditions

#handlers目录用于定义此角色中触发条件时执行的动作。
cd /etc/ansible/roles/nginx/handlers
vim main.yml
- name: reload nginx
  service: name={
   
   {svc}} state=reloaded

2.3 Edit nginx template file

准备default.conf文件
cp default.conf /etc/ansible/roles/nginx/templates/default.conf.j2
cd /etc/ansible/roles/nginx/templates
vim default.conf.j2
--2行--
listen       {
   
   {nginxip_port}};
--8行--
root   {
   
   {root_dir}};
--29行--
 location ~ \.php$ {
          root           {
   
   {root_dir}};
          fastcgi_pass   {
   
   {passip_port}};
          fastcgi_index  index.php;
          fastcgi_param  SCRIPT_FILENAME  {
   
   {root_dir}}$fastcgi_script_name;
          include        fastcgi_params;
      }

2.4 Define variables

#变量放在vars目录下
cd /etc/ansible/roles/nginx/vars
vim main.yml
pkg: nginx
svc: nginx
nginxip_port: 192.168.88.20:80
nginx_servername: www.web.com
root_dir: /usr/share/nginx/html
passip_port: 192.168.88.30:9000

2.5 Prepare to copy files

#files目录存放由 copy 模块或 script 模块调用的文件
cd /etc/ansible/roles/nginx/files
vim index.php
<?php
phpinfo();
?>

vim nginx.repo
[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/7/$basearch/
gpgcheck=0
enabled=1

3. Use roles to create php

3.1 Edit php tasks

cd /etc/ansible/roles/php/tasks
vim main.yml
- name: rpm -Uvh php
  shell: rpm -Uvh https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm && rpm -Uvh https://mirror.webtatic.com/yum/el7/webtatic-release.rpm

- name: install php
  yum: name={
   
   {pkg}} state=latest

- name: create user
  user: name=php shell=/sbin/nologin create_home=no

- name: create directory
  file: name=/usr/share/nginx/html state=directory

- name: copy index.php
  copy: src=index.php dest=/usr/share/nginx/html

- name: php.ini
  replace: path=/etc/php.ini regexp=";date.timezone =" replace="date.timezone = Asia/Shanghai"
  notify: "reload php"

- name: user group
  replace: path=/etc/php-fpm.d/www.conf regexp="apache" replace="php"
  notify: "reload php"

- name: listen
  replace: path=/etc/php-fpm.d/www.conf regexp="listen = 127.0.0.1:9000" replace="listen = 192.168.88.30:9000"
  notify: "reload php"

- name:  allow_clients
  replace: path=/etc/php-fpm.d/www.conf regexp="listen.allowed_clients = 127.0.0.1" replace="listen.allowed_clients = 192.168.88.20"
  notify: "reload php"

- name: start php-fpm
  service: name=php-fpm state=started enabled=yes

3.2 Define actions to be performed when triggering conditions

vim /etc/ansible/roles/php/handlers/main.yml
- name: reload php
  service: name=php-fpm state=reloaded

4. Use roles to create mysql

4.1 Edit mysql script

vim /etc/ansible/roles/mysql/tasks/main.yml
- name: remove mariadb*
  yum: name=mariadb* state=absent

- name: rpm -ivh mysql
  shell: rpm -ivh https://repo.mysql.com/mysql57-community-release-el7-11.noarch.rpm
  ignore_errors: true

- name: mysql.repo
  shell: sed -i 's/gpgcheck=1/gpgcheck=0/' /etc/yum.repos.d/mysql-community.repo

- name: install mysql
  yum: name=mysql-server

- name: start mysql
  service: name=mysqld.service state=started enabled=yes

- name: password.sh
  script: password.sh

- name: remove mysql57
  yum: name=mysql57-community-release-el7-10.noarch state=absent

4.2 Edit script

vim /etc/ansible/roles/mysql/files/password.sh

passd=$(grep "password" /var/log/mysqld.log | awk '{print $NF}')
mysql -uroot -p"$passd" --connect-expired-password -e "ALTER USER 'root'@'localhost' IDENTIFIED BY 'Admin@123';"
mysql -uroot -pAdmin@123 -e "grant all privileges on *.* to root@'%' identified by 'Admin@123' with grant option;"

chmod +x roles/mysql/files/password.sh

5. Modify hosts file

vim /etc/ansible/hosts
[webservers]
192.168.88.20

[dbservers]
192.168.88.30

[mysql]
192.168.88.40

6. Edit the lnmp playbook and execute it

cd /etc/ansible
vim lnmp2.yml
- name: nginx
  hosts: webservers
  roles:
  - nginx

- name: php
  hosts: dbservers
  roles:
  - php

- name: mysql
  hosts: mysql
  roles:
  - mysql

ansible-playbook lnmp2.yml