【3】puppet筆記 - 變量、if、case、selector

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

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

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

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

一、變量

定義變量：以$開頭，如：$system、$flag

賦值：=  ,如：$one = "first one"

引用變量：有三種方法以下

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

輸出：

[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代碼中能夠直接使用的變量：

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語句

if 條件 {

 語句

}

條件：是true執行語句，是false則跳過語句

$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語句

unless 條件 {

語句

}

條件：當false時，執行語句。當true時跳過。

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

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

四、case語句

case 變量/表達式 {

值1 ：{語句1}

值2 : {語句2}

default : {不是上面的值時，執行這條語句}

}

$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語句

未知變量 = 可知變量 ? {

值1 => 賦值1,

值2 => 賦值2,

default => 賦值3,

}

能夠用於系統版本之類的判斷

$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"

官網例子：

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