Puppet条件语句，class，module的使用
一、Puppet条件语句和类
Puppet2.7系列的版本支持使用3种条件判断语句，包括：if，case，selector，puppet也支持使用class是用于通用目标的一组资源，因此，它是命名的代码块，在某位置创建之后可在puppet全局使用，类似于其他编程语言中类的功能，puppet的class可以被继承，也可以包含子类。
二、Puppet模块
到目前为止，资源申报、定义类、声明类等所有功能都只能再一个manifest文件中实现，但这却非最有效的基于puppet管理IT基础架构的方式，实践中，一般需要把manifest文件分解成易于理解的结构，例如将类文件，配置文件、模块文件等分类存放，并且通过某种机制在必要时将它们整合起来，这种机制就是“模块”，它有助于以结构化、层次化的方式使用puppet，而puppet则基于“模块自动装载器”完成模块装载，模块实际就是一个按约定的、预定义的结构存放了多个文件或子目录的目录，目录里的这些文件或子目录必须遵循其命名规范，puppet会按此种规范在特定位置查找所需要的模块文件，不过，这些特定的目录也可以通过puppet的配置参数modulepath定义。
首先来演示下if语句的使用，if又包括单分支，双分支，多分支语句
[root@node1 ~]# vi test6.pp
if $operatingsystem =~ /(?i-mx:^(centos|fedora|redhat))/ {
$webserver = 'httpd'
} elsif operatingsystem =~ /(?i-mx:^(debian|ubuntu))/ {
$webserver = 'apache2'
} else {
$webserver = undef
notice('Unkown OS')
}
package {"$webserver":
ensure => installed,
}
[root@node1 ~]# puppet apply test6.pp
notice: /Stage[main]//Package[httpd]/ensure: created
notice: Finished catalog run in 2.91 seconds
[root@node1 ~]# rpm -q httpd
httpd-2.2.15-30.el6.centos.x86_64
# 使用多分支if判断语句，operatingsystem顶级变量，根据当前系统安装所要安装的程序包
case语句，类似if语句，case语句会从多个代码块中选择一个分支执行，这跟其他编程语言中的case语句功能一致，case语句会接受一个控制表达式和一组case代码块，并执行第一个匹配到控制表达式的块
[root@node1 ~]# vi test7.pp
case $operatingsystem {
'Solaris': {notice("Welcome to Solaris")}
'RedHat','CentOS': {notice("Welcome to RedHat OSFamily")}
/^(Debian|Ubuntu)$/: {notice("Welcome to $1 linux")}
default: {notice("Welcome,alien *_*")}
}
[root@node1 ~]# puppet apply test7.pp
notice: Scope(Class[main]): Welcome to RedHat OSFamily
notice: Finished catalog run in 0.01 seconds
selector语句，selector只能用于期望出现直接值的地方，这包括变量赋值，资源属性，函数参数，资源标题，其他selector的值及表达式，selector不能用于一个已经嵌套于selector的case中，也不能用于一个已经嵌套于case的case语句中
[root@node1 ~]# vi test8.pp
$webserver = $operatingsystem ? {
/(?i-mx:ubuntu|debian)/ => 'apache2',
/(?i-mx:centos|fedora|redhat)/ => 'httpd',
}
notify {"$webserver":
message => "install $webserver",
}
[root@node1 ~]# puppet apply test8.pp
notice: install httpd
notice: /Stage[main]//Notify[httpd]/message: defined 'message' as 'install httpd'
notice: Finished catalog run in 0.02 seconds
class的使用
[root@node1 ~]# vi test9.pp
class nginx {
package {'nginx':
ensure => installed,
before => File['/etc/nginx/nginx.conf'],
}
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => 0644,
owner => 'root',
group => 'root',
source => '/tmp/nginx.conf',
notify => Service['nginx'],
}
service { 'nginx':
ensure => running,
}
}
include nginx
# 使用include来调用class
[root@node1 ~]# puppet apply test9.pp
notice: /Stage[main]/Nginx/Package[nginx]/ensure: created
notice: /Stage[main]/Nginx/File[/etc/nginx/nginx.conf]/content: content changed '{md5}d9dfc198c249bb4ac341198a752b9458' to '{md5}95f45f10386878664af2b7ccd1536ea4'
notice: /Stage[main]/Nginx/Service[nginx]/ensure: ensure changed 'stopped' to 'running'
notice: /Stage[main]/Nginx/Service[nginx]: Triggered 'refresh' from 1 events
notice: Finished catalog run in 2.16 seconds
# 也可以使用以下方式调用，这种方式可以传递参数
class nginx {
package {'nginx':
ensure => installed,
before => File['/etc/nginx/nginx.conf'],
}
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => 0644,
owner => 'root',
group => 'root',
source => '/tmp/nginx.conf',
notify => Service['nginx'],
}
service { 'nginx':
ensure => running,
}
}
class {'nginx':}
[root@node1 ~]# puppet apply test9.pp
notice: /Stage[main]/Nginx/Package[nginx]/ensure: created
notice: /Stage[main]/Nginx/File[/etc/nginx/nginx.conf]/content: content changed '{md5}d9dfc198c249bb4ac341198a752b9458' to '{md5}95f45f10386878664af2b7ccd1536ea4'
notice: /Stage[main]/Nginx/Service[nginx]/ensure: ensure changed 'stopped' to 'running'
notice: /Stage[main]/Nginx/Service[nginx]: Triggered 'refresh' from 1 events
notice: Finished catalog run in 2.06 seconds
使用class方法调用类，还可以传递参数实现，根据参数来安装不同的服务，比如想安装tengine
[root@node1 ~]# vi test9.pp
class webserver ($wbsvr='nginx') {
package {"$wbsvr":
ensure => installed,
before => File['/etc/nginx/nginx.conf'],
}
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => 0644,
owner => 'root',
group => 'root',
source => '/tmp/nginx.conf',
notify => Service['nginx'],
}
service { 'nginx':
ensure => running,
}
}
class {'webserver':
wbsvr => 'nginx',
}
[root@node1 ~]# puppet apply test9.pp
notice: /Stage[main]/Webserver/Package[nginx]/ensure: created
notice: /Stage[main]/Webserver/File[/etc/nginx/nginx.conf]/content: content changed '{md5}d9dfc198c249bb4ac341198a752b9458' to '{md5}95f45f10386878664af2b7ccd1536ea4'
notice: /Stage[main]/Webserver/Service[nginx]/ensure: ensure changed 'stopped' to 'running'
notice: /Stage[main]/Webserver/Service[nginx]: Triggered 'refresh' from 1 events
notice: Finished catalog run in 2.09 seconds
[root@node1 ~]# vi test9.pp
class webserver ($wbsvr='nginx') {
package {"$wbsvr":
ensure => installed,
before => File['/etc/nginx/nginx.conf'],
}
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => 0644,
owner => 'root',
group => 'root',
source => '/tmp/nginx.conf',
notify => Service['nginx'],
}
service { 'nginx':
ensure => running,
}
}
class {'webserver':
wbsvr => 'tenginx',
}
[root@node1 ~]# puppet apply test9.pp
err: /Stage[main]/Webserver/Package[tenginx]/ensure: change from absent to present failed: Execution of '/usr/bin/yum -d 0 -e 0 -y install tenginx' returned 1: Error: Nothing to do
notice: /Stage[main]/Webserver/File[/etc/nginx/nginx.conf]: Dependency Package[tenginx] has failures: true
warning: /Stage[main]/Webserver/File[/etc/nginx/nginx.conf]: Skipping because of failed dependencies
notice: /Stage[main]/Webserver/Service[nginx]: Dependency Package[tenginx] has failures: true
warning: /Stage[main]/Webserver/Service[nginx]: Skipping because of failed dependencies
notice: Finished catalog run in 0.41 second
类也可以被继承，实现根据不同情况调用不同的类
[root@node1 ~]# vi test10.pp
class nginx {
package {'nginx':
ensure => installed,
}
}
class nginx::websvr inherits nginx {
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => '0644',
owner => 'root',
group => 'root',
require => Package['nginx'],
source => '/tmp/nginx.conf',
}
service {'nginx':
ensure => running,
}
}
class nginx::rproxy inherits nginx {
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => '0644',
owner => 'root',
group => 'root',
require => Package['nginx'],
source => '/tmp/nginx-proxy.conf',
}
service {'nginx':
ensure => running,
}
}
include nginx::websvr
[root@node1 ~]# puppet apply test10.pp
notice: /Stage[main]/Nginx/Package[nginx]/ensure: created
notice: /Stage[main]/Nginx::Websvr/File[/etc/nginx/nginx.conf]/content: content changed '{md5}d9dfc198c249bb4ac341198a752b9458' to '{md5}95f45f10386878664af2b7ccd1536ea4'
notice: /Stage[main]/Nginx::Websvr/Service[nginx]/ensure: ensure changed 'stopped' to 'running'
notice: Finished catalog run in 1.81 seconds
# 调用nginx::rproxy类
[root@node1 ~]# vi test10.pp
class nginx {
package {'nginx':
ensure => installed,
}
}
class nginx::websvr inherits nginx {
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => '0644',
owner => 'root',
group => 'root',
require => Package['nginx'],
source => '/tmp/nginx.conf',
}
service {'nginx':
ensure => running,
}
}
class nginx::rproxy inherits nginx {
file {'/etc/nginx/nginx.conf':
ensure => file,
mode => '0644',
owner => 'root',
group => 'root',
require => Package['nginx'],
source => '/tmp/nginx-proxy.conf',
}
service {'nginx':
ensure => running,
}
}
include nginx::rproxy
[root@node1 ~]# puppet apply test10.pp
notice: Finished catalog run in 0.15 seconds
puppet模块的创建和使用
# 安装puppet-server [root@node1 ~]# rpm -ivh puppet-server-2.7.23-1.el6.noarch.rpm
# 创建模块目录结构
[root@node1 ~]# mkdir -pv /etc/puppet/modules/nginx/{manifests,files,lib,templates,tests,spec}
mkdir: created directory `/etc/puppet/modules/nginx'
mkdir: created directory `/etc/puppet/modules/nginx/manifests'
mkdir: created directory `/etc/puppet/modules/nginx/files'
mkdir: created directory `/etc/puppet/modules/nginx/lib'
mkdir: created directory `/etc/puppet/modules/nginx/templates'
mkdir: created directory `/etc/puppet/modules/nginx/tests'
mkdir: created directory `/etc/puppet/modules/nginx/spec'
[root@node1 ~]# puppet module list
/etc/puppet/modules
└── nginx (???)
/usr/share/puppet/modules (no modules installed)
MODULE NAME：模块名称，只能以小写字母开头，也可以包含小写字母、数字和下划线，但不能使用“main”或者“settings”作为模块名；
manifests目录：包含当前模块的所有manifest文件；每个mainfest文件必须包含一个类或一个定义的类，此文件访问路径格式为"ModuleName::[SubDircetoryName::]ManifestFileName"，注意manifest文件不需要其后缀.pp；
init.pp：只能包含一个单独的类定义，且类的名称必须与模块名称相同；
files目录：包含了一组静态文件，这些文件可被节点下载使用，每个文件的访问路径遵循
puppet:///modules/MODULE_NAME/filename路径格式；
lib目录：插件目录，常用于自定义fact及自定义资源类型等；
templates目录：存储了manifest用到的模板文件，其访问路径遵循template('ModulName/TemplateName')格式；
tests目录：当前模块的使用帮助或使用范例文件，类似如何声明当前模块中的类定义的类型等；
spec目录：类似于tests目录的功能，只不过，其是为lib目录中定义的各插件提供使用的范例的；
在nginx模块中定义init.pp
[root@node1 ~]# vi /etc/puppet/modules/nginx/manifests/init.pp
class nginx {
package {'nginx':
ensure => installed,
}
}
定义nginx_web.pp文件
[root@node1 ~]# vi /etc/puppet/modules/nginx/manifests/nginx_web.pp
class nginx::nginx_web inherits nginx {
file {'/etc/nginx/nginx.conf':
ensure => file,
source => 'puppet:///modules/nginx/nginx-web.conf',
mode => '0644',
owner => 'root',
group => 'root',
notify => Service['nginx'],
require => Package['nginx'],
}
service {'nginx':
ensure => running,
}
}
# 准备source文件
[root@node1 ~]# cp /tmp/nginx.conf /etc/puppet/modules/nginx/files/nginx-web.conf
定义nginx_proxy.pp文件
[root@node1 ~]# vi /etc/puppet/modules/nginx/manifests/nginx_proxy.pp
class nginx::nginx_proxy inherits nginx {
file {'/etc/nginx/nginx.conf':
ensure => file,
source => 'puppet:///modules/nginx/nginx-proxy.conf',
mode => '0644',
owner => 'root',
group => 'root',
notify => Service['nginx'],
require => Package['nginx'],
}
service {'nginx':
ensure => running,
}
}
# 准备source文件
[root@node1 ~]# cp /tmp/nginx.conf /etc/puppet/modules/nginx/files/nginx-proxy.conf
创建site.pp文件调用前面定义的class
[root@node1 ~]# vi /etc/puppet/manifests/site.pp
node 'node1.luojianlong' {
include nginx::nginx_web
}
执行操作
[root@node1 ~]# puppet apply /etc/puppet/manifests/site.pp
notice: /Stage[main]/Nginx/Package[nginx]/ensure: created
notice: /Stage[main]/Nginx::Nginx_web/File[/etc/nginx/nginx.conf]/content: content changed '{md5}d9dfc198c249bb4ac341198a752b9458' to '{md5}95f45f10386878664af2b7ccd1536ea4'
notice: /Stage[main]/Nginx::Nginx_web/Service[nginx]/ensure: ensure changed 'stopped' to 'running'
notice: /Stage[main]/Nginx::Nginx_web/Service[nginx]: Triggered 'refresh' from 1 events
notice: Finished catalog run in 2.05 seconds
这样就是使用nginx-web.conf配置文件启动的nginx
也可以使用nginx-proxy.conf，启动
[root@node1 ~]# vi /etc/puppet/manifests/site.pp
node 'node1.luojianlong' {
include nginx::nginx_proxy
}
[root@node1 ~]# yum -y remove nginx
[root@node1 ~]# puppet apply /etc/puppet/manifests/site.pp
notice: /Stage[main]/Nginx/Package[nginx]/ensure: created
notice: /Stage[main]/Nginx::Nginx_proxy/File[/etc/nginx/nginx.conf]/content: content changed '{md5}d9dfc198c249bb4ac341198a752b9458' to '{md5}95f45f10386878664af2b7ccd1536ea4'
notice: /Stage[main]/Nginx::Nginx_proxy/Service[nginx]/ensure: ensure changed 'stopped' to 'running'
notice: /Stage[main]/Nginx::Nginx_proxy/Service[nginx]: Triggered 'refresh' from 1 events
notice: Finished catalog run in 2.11 seconds
# 执行成功
到此，Puppet条件语句，class，module的使用就介绍这么多了。