一 目錄結構圖
[root@localhost lamp_haproxy]# tree
.
├── group_vars
│ ├── all
│ ├── dbservers
│ ├── lbservers
│ └── webservers
├── hosts
├── roles
│ ├── base-apache
│ │ └── tasks
│ │ └── main.yml
│ ├── common
│ │ ├── files
│ │ │ ├── epel.repo
│ │ │ └── RPM-GPG-KEY-EPEL-6
│ │ ├── handlers
│ │ │ └── main.yml
│ │ ├── tasks
│ │ │ └── main.yml
│ │ └── templates
│ │ ├── iptables.j2
│ │ └── ntp.conf.j2
│ ├── db
│ │ ├── handlers
│ │ │ └── main.yml
│ │ ├── tasks
│ │ │ └── main.yml
│ │ └── templates
│ │ └── my.cnf.j2
│ ├── haproxy
│ │ ├── handlers
│ │ │ └── main.yml
│ │ ├── tasks
│ │ │ └── main.yml
│ │ └── templates
│ │ └── haproxy.cfg.j2
│ ├── nagios
│ │ ├── files
│ │ │ ├── ansible-managed-services.cfg
│ │ │ ├── localhost.cfg
│ │ │ └── nagios.cfg
│ │ ├── handlers
│ │ │ └── main.yml
│ │ ├── tasks
│ │ │ └── main.yml
│ │ └── templates
│ │ ├── dbservers.cfg.j2
│ │ ├── lbservers.cfg.j2
│ │ └── webservers.cfg.j2
│ └── web
│ └── tasks
│ └── main.yml
└── site.yml
二 設備環境說明
1 說明
兩臺Web主機、1臺數據庫主機、1臺負載均衡器主機、1臺監控主機。
2 hosts文件
[root@localhost lamp_haproxy]# cat hosts
[webservers]
web1
web2
[dbservers]
db1
[lbservers]
lb1
[monitoring]
nagios
三 入口文件
1 說明
需要注意的是base-apache角色，由於webservers及monitoring都需要部署Apache環境，爲提高複用性，將部署Apache獨立成base-apache角色。
2 Site.yml
[webservers]
web1
web2
[dbservers]
db1
[lbservers]
lb1
[monitoring]
nagios
[root@localhost lamp_haproxy]# cat site.yml
---
# This playbook deploys the whole application stack in this site.
# Apply common configuration to all hosts
- hosts: all
roles:
- common
# Configure and deploy database servers.
- hosts: dbservers
user: root
roles:
- db
# Configure and deploy the web servers. Note that we include two roles here,
# the 'base-apache' role which simply sets up Apache, and 'web' which includes
# our example web application.
- hosts: webservers
user: root
roles:
- base-apache
- web
# Configure and deploy the load balancer(s).
- hosts: lbservers
user: root
roles:
- haproxy
# Configure and deploy the Nagios monitoring node(s).
- hosts: monitoring
user: root
roles:
- base-apache
- nagios
四 定義組變量
1 全局變量
1.1 說明
變量作用域爲所有主機，all文件定義了匹配所有主機作用域的變量，一般爲系統公共類基 礎配置，如ntpserver地址、sysctl變量、iptables配置等。
1.2 代碼
---
# Variables here are applicable to all host groups
httpd_port: 80
ntpserver: 192.168.1.2
2 定義webservers組的變量
2.1 說明
變量作用域爲webservers組主機。webservers文件定義了webservers組作用域的變量。本示例涉及Apache相關配置，其中“iface：'{{ansible_default_ipv4.interface}}'”引用了 Facts獲取的本地網卡接口名信息，另外定義了一個GitHub的repository， 方便下載Web測試文件，如內部搭建git版本控制環境，此處也可以修改成本地的服務地址。
2.2 代碼
---
# Variables for the web server configuration
# Ethernet interface on which the web server should listen.
# Defaults to the first interface. Change this to:
#
# iface: eth1
#
# ...to override.
#
iface: '{{ ansible_default_ipv4.interface }}'
# this is the repository that holds our sample webapp
repository: https://github.com/bennojoy/mywebapp.git
# this is the sha1sum of V5 of the test webapp.
webapp_version: 351e47276cc66b018f4890a04709d4cc3d3edb0d
3 dbservers組的變量
3.1 說明
變量作用域爲dbservers組主機。dbservers文件定義了dbservers組作用域變量，本示例涉及MySQL 數據庫的基本應用信息。
3.2 代碼
---
# The variables file used by the playbooks in the dbservers group.
# These don't have to be explicitly imported by vars_files: they are autopopulated.
mysqlservice: mysqld
mysql_port: 3306
dbuser: root
dbname: foodb
upassword: abc
4 lbservers組作用域變量
4.1 說明
定義lbservers組作用域變量文件，本示例主要涉及haproxy環境涉及的配置參數值。
4.2 代碼
---
# Variables for the HAproxy configuration
# HAProxy supports "http" and "tcp". For SSL, SMTP, etc, use "tcp".
mode: http
# Port on which HAProxy should listen
listenport: 8888
# A name for the proxy daemon, this wil be the suffix in the logs.
daemonname: myapplb
# Balancing Algorithm. Available options:
# roundrobin, source, leastconn, source, uri
# (if persistance is required use, "source")
balance: roundrobin
# Ethernet interface on which the load balancer should listen
# Defaults to the first interface. Change this to:
#
# iface: eth1
#
# ...to override.
#
iface: '{{ ansible_default_ipv4.interface }}'