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一 点睛
本实战有两个角色，一个是web角色，一个是公共类角色common。
common角色是从角色全局作用域中抽取出公共的部分，一般为系统的基础服务，比如ntp、iptables、selinux、sysctl等。本实战是针对ntp服务的管理。
二 playbook目录结构
playbook目录包括变量定义目录group_vars、主机组定义文件 hosts、全局配置文件site.yml、角色功能目录。
[root@localhost nginx]# tree
.
├── group_vars
│ ├── all
│ └── webservers
├── hosts
├── roles
│ ├── common
│ │ ├── handlers
│ │ │ └── main.yml
│ │ ├── tasks
│ │ │ └── main.yml
│ │ ├── templates
│ │ │ └── ntp.conf.j2
│ │ └── vars
│ │ └── main.yml
│ └── web
│ ├── handlers
│ │ └── main.yml
│ ├── tasks
│ │ └── main.yml
│ └── templates
│ └── nginx2.conf
└── site.yml
11 directories, 11 files三 定义主机组
以下定义了一个业务组webservers，成员为两台主机。
[webservers]
192.168.0.101
192.168.0.102非必选配置，默认将引用/etc/ansible/hosts的参数，角色中自定义组与主机文件将通过“-i file”命令行参数调用，如ansible-playbook -i hosts 来调用。
四 定义主机或组变量
1 点睛
group_vars为定义组变量目录，目录当中的文件名要与组名保持一致，组变量文件定义的变量作为域只受限于该组，all代表所有主机。
2 示例
nginx/group_vars/all
[root@localhost group_vars]# cat all
---
# Variables listed here are applicable to all host groups
ntpserver: ntp.sjtu.edu.cnnginx/group_vars/webservers
[root@localhost group_vars]# cat webservers
---
worker_processes: 4
num_cpus: 4
max_open_file: 65536
root: /data五 全局配置文件site.yml
1 点睛
下面的全局配置文件引用了两个角色块，角色的应用范围及实现功能都不一样：
nginx/site.yml
[root@localhost nginx]# cat site.yml
---
- name: apply common configuration to all nodes
hosts: all
roles:
- common
- name: configure and deploy the webservers and application code
hosts: webservers
roles:
- web全局配置文件site.yml引用了两个角色，一个为公共类的common， 另一个为web类，分别对应nginx/common、nginx/web目录。以此类推， 可以引用更多的角色，如db、nosql、hadoop等，前提是我们先要进行定义，通常情况下一个角色对应着一个特定功能服务。通过hosts参数来绑定角色对应的主机或组。
六 角色common的定义
角色common定义了handlers、tasks、templates、vars 4个功能类， 分别存放处理程序、任务列表、模板、变量的配置文件main.yml，需要注意的是，vars/main.yml中定义的变量优先级高于/nginx/group_vars/all。
handlers/main.yml
[root@localhost handlers]# cat main.yml
- name: restart ntp
service: name=ntpd state=restartedtasks/main.yml
[root@localhost tasks]# cat main.yml
- name: Install ntp
yum: name=ntp state=present
# tags: ntp
- name: Configure ntp file
template: src=ntp.conf.j2 dest=/etc/ntp.conf
# tags: ntp
notify: restart ntp
- name: Start the ntp service
service: name=ntpd state=started enabled=true
# tags: ntp
- name: test to see if selinux is running
command: getenforce
register: sestatus
changed_when: false其中template：src=ntp.conf.j2引用模板时无需写路径，默认在上级 的templates目录中查找。
templates/ntp.conf.j2
driftfile /var/lib/ntp/drift
restrict 127.0.0.1
restrict -6 ::1
server {{ ntpserver }}
includefile /etc/ntp/crypto/pw
keys /etc/ntp/keys此处{{ntpserver}}将引用vars/main.yml定义的ntpserver变量。
vars/main.yml
[root@localhost vars]# cat main.yml
---
# Variables listed here are applicable to all host groups
ntpserver: 210.72.145.44七 角色web的定义
角色web定义了handlers、tasks、templates三个功能类。
handlers/main.yml
[root@localhost handlers]# cat main.yml
- name: restart nginx
service: name=nginx state=restartedtasks/main.yml
[root@localhost web]# cat tasks/main.yml
- name: ensure nginx is at the latest version
yum: pkg=nginx state=latest
- name: write the nginx config file
template: src=nginx2.conf dest=/etc/nginx/nginx.conf
notify:
- restart nginx
- name: ensure nginx is running
service: name=nginx state=startedtemplates/nginx2.conf
[root@localhost templates]# cat nginx2.conf
#version 1.1.4
# For more information on configuration, see:
# * Official English Documentation: http://nginx.org/en/docs/
# * Official Russian Documentation: http://nginx.org/ru/docs/
user nginx;
worker_processes {{ worker_processes }};
{% if num_cpus == 2 %}
worker_cpu_affinity 01 10;
{% elif num_cpus == 4 %}
worker_cpu_affinity 1000 0100 0010 0001;
{% elif num_cpus >= 8 %}
worker_cpu_affinity 00000001 00000010 00000100 00001000 00010000 00100000 01000000 10000000;
{% else %}
worker_cpu_affinity 1000 0100 0010 0001;
{% endif %}
worker_rlimit_nofile {{ max_open_file }};
error_log /var/log/nginx/error.log;
#error_log /var/log/nginx/error.log notice;
#error_log /var/log/nginx/error.log info;
pid /var/run/nginx.pid;
events {
worker_connections {{ max_open_file }};
}
http {
include /etc/nginx/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 /var/log/nginx/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 75;
#gzip on;
# Load config files from the /etc/nginx/conf.d directory
# The default server is in conf.d/default.conf
#include /etc/nginx/conf.d/*.conf;
server {
listen 80 default_server;
server_name _;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
root {{ root }};
index index.html index.htm;
}
error_page 404 /404.html;
location = /404.html {
root /usr/share/nginx/html;
}
# redirect server error pages to the static page /50x.html
#
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
}
}八 运行角色
[root@localhost nginx]# pwd
/home/pyauto-master/9/ansible/playbooks/nginx
[root@localhost nginx]# ansible-playbook -i hosts site.yml -f 2
PLAY [apply common configuration to all nodes] *******************************************************
TASK [Gathering Facts] *******************************************************************************
ok: [192.168.0.102]
ok: [192.168.0.101]
TASK [common : Install ntp] **************************************************************************
changed: [192.168.0.102]
changed: [192.168.0.101]
TASK [common : Configure ntp file] *******************************************************************
changed: [192.168.0.102]
changed: [192.168.0.101]
TASK [common : Start the ntp service] ****************************************************************
changed: [192.168.0.102]
changed: [192.168.0.101]
TASK [common : test to see if selinux is running] ****************************************************
ok: [192.168.0.101]
ok: [192.168.0.102]
RUNNING HANDLER [common : restart ntp] ***************************************************************
changed: [192.168.0.102]
changed: [192.168.0.101]
PLAY [configure and deploy the webservers and application code] **************************************
TASK [Gathering Facts] *******************************************************************************
ok: [192.168.0.102]
ok: [192.168.0.101]
TASK [web : ensure nginx is at the latest version] ***************************************************
changed: [192.168.0.102]
changed: [192.168.0.101]
TASK [web : write the nginx config file] *************************************************************
changed: [192.168.0.102]
changed: [192.168.0.101]
TASK [web : ensure nginx is running] *****************************************************************
changed: [192.168.0.101]
changed: [192.168.0.102]
RUNNING HANDLER [web : restart nginx] ****************************************************************
changed: [192.168.0.101]
changed: [192.168.0.102]
PLAY RECAP *******************************************************************************************
192.168.0.101 : ok=11 changed=8 unreachable=0 failed=0
192.168.0.102 : ok=11 changed=8 unreachable=0 failed=0