第5天：Ansible-Playbook

Ansible中的每个模块专注于某一方面的功能。虽然每个模块实现的功能都比较简单，但是，将各个模块结合起来就可以实现比较复杂的功能。在Ansible中，将各个模块组合起来的文件是一个YAML格式的配置文件。这个配置文件，在Ansible中称为Playbook。

 Nginx示例

---
- hosts: webservers #指定执行任务的主机，可以是一个或多个由冒号分割的主机组
  vars: #定义变量
    worker_processes: 4
    num_cpus: 4
    max_open_file: 65506
    root: /data/www
  remote_user: heboan #指定远程主机上执行任务的用户
  sudo: yes
  tasks:  #定义任务，任务列表中的各任务按次序逐个在hosts指定的主机上执行，即在所有主机上完成一个任务后再开始第二个，如果中途出错，所有已执行的任务都回滚
    - name: install depend packages
      command: yum install -y gcc gcc-c++ openssl-devel pcre-devel
    - name:  unarchive nginx-1.12.2.tar.gz
      unarchive: src=/etc/ansible/templates/nginx/nginx-1.12.2.tar.gz dest=/home/heboan/tools
    - name: create nginx user
      user: name=nginx shell=/sbin/nologin
    - name: install nginx
      shell: cd /home/heboan/tools/nginx-1.12.2 && ./configure --prefix=/opt/app/nginx --user=nginx --group=nginx && make && make install
    - name: cp nginx.service
      copy: src=/etc/ansible/templates/nginx/nginx.service dest=/usr/lib/systemd/system/nginx.service
    - name: copy index.html
      copy: src=/etc/ansible/templates/nginx/index.html dest=/data/www/index.html
    - name: start nginx
      service: name=nginx state=started
    - name: write the nginx config file
      template: src=/etc/ansible/templates/nginx/nginx2.conf dest=/opt/app/nginx/conf/nginx.conf #这是模板，里面可以识别上面定义的变量
      notify:  #执行完任务(write the nginx config file)的关联操作
        - reload nginx  #触发此操作，下面需要定义操作内容
  handlers:  #定义关联操作
    - name: reload nginx  #关联操作任务
      service: name=nginx state=restarted

user  nginx;
worker_processes  {{worker_processes}};

error_log  logs/error.log;
pid        logs/nginx.pid;


events {
    worker_connections  1024;
}

worker_rlimit_nofile {{max_open_file}};

http {
    include       mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    tcp_nopush     on;

    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       80;
        server_name  localhost;
        root {{root}};

        location / {
        }

    }

}

[Unit]
 Description=nginx - high performance web server
 Documentation=http://nginx.org/en/docs/
 After=network.target remote-fs.target nss-lookup.target
  
 [Service]
 Type=forking
 PIDFile=/opt/app/nginx/logs/nginx.pid
 ExecStartPre=/opt/app/nginx/sbin/nginx -t -c /opt/app/nginx/conf/nginx.conf
 ExecStart=/opt/app/nginx/sbin/nginx -c /opt/app/nginx/conf/nginx.conf
 ExecReload=/bin/kill -s HUP $MAINPID
 ExecStop=/bin/kill -s QUIT $MAINPID
 PrivateTmp=true
  
 [Install]
 WantedBy=multi-user.target