【3】puppet笔记 - 变量、if、case、selector

变量：http://docs.puppetlabs.com/facter/latest/core_facts.html

http://docs.puppetlabs.com/puppet/latest/reference/lang_variables.html

语句：http://docs.puppetlabs.com/puppet/latest/reference/lang_conditional.html

     http://docs.puppetlabs.com/puppet/latest/reference/lang_expressions.html

一、变量

定义变量：以$开头，如：$system、$flag

赋值：=  ,如：$one = "first one"

引用变量：有三种方法以下

$var = "Hello World!"
notice "1.$var"
notice "2.${var}"
notice "3.$::var"

输出：

[root@pclient test]# puppet apply 3.pp
Notice: Scope(Class[main]): 1.Hello World!
Notice: Scope(Class[main]): 2.Hello World!
Notice: Scope(Class[main]): 3.Hello World!
Notice: Compiled catalog for pclient.onepc.com in environment production in 0.06 seconds
Notice: Finished catalog run in 0.05 seconds

puppet代码中能够直接使用的变量：

http://docs.puppetlabs.com/facter/latest/core_facts.html

Summary
architecture
augeasversion
blockdevice_{devicename}_size
blockdevice_{devicename}_vendor
blockdevice_{devicename}_model
blockdevices
boardmanufacturer
boardproductname
boardserialnumber
cfkey
domain
ec2_{EC2 INSTANCE DATA}
ec2_userdata
facterversion
filesystems
ldom
fqdn
gid
hardwareisa
hardwaremodel
hostname
id
interfaces
ipaddress
ipaddress_{NETWORK INTERFACE}
ipaddress6
ipaddress6_{NETWORK INTERFACE}
iphostnumber
is_virtual
kernel
kernelmajversion
kernelrelease
kernelversion
lsbdistcodename
lsbdistdescription
lsbdistid
lsbdistrelease
lsbmajdistrelease
lsbminordistrelease
lsbrelease
macaddress
macaddress_{NETWORK INTERFACE}
macosx_buildversion
macosx_productname
macosx_productversion
macosx_productversion_major
macosx_productversion_minor
manufacturer
memoryfree
memorysize
netmask
netmask_{NETWORK INTERFACE}
network_{NETWORK INTERFACE}
operatingsystem
operatingsystemmajrelease
operatingsystemrelease
osfamily
path
physicalprocessorcount
processor
processor{NUMBER}
processorcount
productname
ps
puppetversion
rubysitedir
rubyversion
selinux
selinux_config_mode
selinux_config_policy
selinux_current_mode
selinux_enforced
selinux_policyversion
serialnumber
sp_{SYSTEM PROFILER DATA}
sshdsakey
sshecdsakey
sshrsakey
swapencrypted
swapfree
swapsize
timezone
type
uniqueid
uptime
uptime_days
uptime_hours
uptime_seconds
uuid
virtual
vlans
xendomains
zfs_version
zonename
zones
zpool_version

二、if语句

if 条件 {

 语句

}

条件：是true执行语句，是false则跳过语句

$varif = 20
if $varif > 10 {
  notice "$varif > 10"
} else {
  notice "$varif < 10"
}

注意：elsif 不是 elseif
if $varif == 30 {
  notice "varif=30" } elsif $varif > 30 {notice "varif>30" }
else { notice "varif < 30" }

三、unless语句

unless 条件 {

语句

}

条件：当false时，执行语句。当true时跳过。

$varless = 100
unless $varless > 1000 {
  notice "$varless > 1000 is false"
}

Notice: Scope(Class[main]): 100 > 1000 is false

四、case语句

case 变量/表达式 {

值1 ：{语句1}

值2 : {语句2}

default : {不是上面的值时，执行这条语句}

}

$varcase = 100
case $varcase {
   10: {notice "varcase = 10"}
   20: {notice "varcase = 20"}
   100: {notice "varcase = 100"}
   default: {notice "varcase is match"}
}

Notice: Scope(Class[main]): varcase = 100

五、selectors语句

未知变量 = 可知变量 ? {

值1 => 赋值1,

值2 => 赋值2,

default => 赋值3,

}

能够用于系统版本之类的判断

$varselectors = "puppet"
$varsel = $varselectors ? {
 "centos" => "this is centos",
 "puppet" => "this is puppet",
 default => "this is default",
}
notice "varsel is value = \"$varsel\""

Notice: Scope(Class[main]): varsel is value = "this is puppet"

官网例子：

$rootgroup = $osfamily ? {
    'Solaris'          => 'wheel',
    /(Darwin|FreeBSD)/ => 'wheel',
    default            => 'root',
}
file { '/etc/passwd':
  ensure => file,
  owner  => 'root',
  group  => $rootgroup,
}