整個selector語句會被當作一個單獨的值，puppet會将控制變量按列出的次序依次與每個case進行比較，并在遇到一個比對的case後，将其值作為整個語句的值進行傳回，并忽略後面的其他case；控制變量與各case比較的方式和case語句相同，但如果沒有任何一個case與控制變量比對，puppet在編譯時将報錯，是以，我們在使用selector必須提供一個default case;控制變量隻能是一個變量或一個有傳回值的函數，不能使用表達式；各個case的值可以是字元串，變量，有傳回值的函數，正規表達式或default；
前文我們了解了puppet的file、exec、cron、notify這四種核心資源類型的使用以及資源見定義通知/訂閱關系，回顧請參考https://www.cnblogs.com/qiuhom-1874/p/14073437.html；今天我們來了解下puppet中的變量、正規表達式、流程控制、類和模闆的相關話題；
puppet中的變量
在puppet中變量的定義和使用都是要加“$”，比如定義變量$webserver=nginx；則表示把nginx這個字元串複制給$webserver這個變量；引用變量直接使用$webserver即可；在puppet中指派操作符為“=”,表示把等号右邊邊的值賦給左邊的變量，任何正常資料類型（非正則）的值都可以賦予puppet中的變量，比如字元串、數值、布爾值、數組、hash以及特殊的undef值（即變量未指派）；
puppet中的資料類型
字元型：非結構化的文本字元串，可以使用引号，也可以不使用引号；單引号表示強引用，雙引号表示弱引用；所謂強引用表示變量不會替換，弱引用表示能夠進行變量替換；字元型值是支援用轉義符；
數字型：可為整數或浮點數，不過，puppet隻有在數值上下文才把數值當作數值型對待，其他情況一律以字元型處理；比如進行加減乘除等運算時，它會把數值型值當作數值進行計算；
數組：數組值為中括号“[]”中的以逗号分隔的項目清單，最後一個項目後面可以沒有逗号；數組中的元素可以為任意可用資料類型，包括hash或其他數組，數組中的元素為數組，我們把這樣的數組叫多元數組；數組的索引為從0開始的整數，也可以使用負數索引；
布爾型：true和false,不能加任何引号；if語句的測試條件和比較表達式都會傳回布爾型值，另外，其他資料類型也可以自動轉換為布爾型值，如字元串，空串為false,非空則true;數值型就是0為false,非0為true等等；
undef：從未被聲明的變量的值類型即為undef；也可手動為某變量賦予undef值，即直接使用不加引号的undef字元串；有點類似shell中的unset；
hash：即為外鍵值資料類型，鍵和值之間使用“=>”分隔，鍵值對定義在“{}”中，彼此間以逗号分隔；其鍵為字元型資料，而值可以為puppet中支援的任意資料類型；通路hash類型的資料元素要使用“鍵”當作索引進行通路；
puppet中變量作用域
提示：所謂變量作用域表示變量的使用生效的範圍，在puppet中作用域可用于限定變量及資源預設屬性的作用範圍；但不能用于限定資源名稱及資源引用的生效範圍；任何給定的scope都可以通路它自己的内容，以及接收來自于其父scope、節點scope以及top scope的内容；簡單講就是作用域小的可以引用作用域大的變量，也可以更改作用域大的變量的值；但是作用域大的不能操作作用域小的變量；如上圖所示，top scope僅能通路直接的變量和屬性預設值；node scope能通路自己的及top scope的變量和屬性預設值；example::parent,example::other和example::four能通路自己的以及節點scope和top scope的變量和預設值；如果要通路非目前scope中的變量，則需要通過完全限制名稱進行；如$vhostdir=$apache::params::vhostdir；這裡需要注意一點，如果top scope的名稱為空，如要引用其變量可以使用類似$::sofamily的方式進行引用；
puppet中的内建變量
在puppet中變量來源可以從facter，agent，master，解釋器以及使用者自定義的變量；其中facter是一個工具，它可以收集系統資訊，規範化之後存放在一系列變量中，并傳遞給puppet;facter的各變量是top scope的變量，這意味着，可以在各個manifest中直接通過${fact name}通路所需的fact變量；檢視系統fact變量有哪些，可以使用facter -p輸出fact變量；agent端的變量常用的有$environment這表示agent端的環境變量，$clientcert表示agent端的證書；$clientversion表示agent puppet的版本資訊；master 端常用變量有$servername，該變量表示服務端名稱；$serverip服務端ip，$serverversion服務端puppet的版本資訊；解釋器中的變量$module_name表示正在執行的子產品名稱；這裡需要注意agent和master的内建變量隻有在master/agent這種模型中才有效，單機模型無效；
puppet中常用的操作符
| 操作符 | 描述 | ||||
| == | 等于 | =~ | 正則模式比對 | + | 加 |
| ！= | 不等于 | !~ | 正則模式不比對 | - | 減 |
| < | 小于 | in | 成員關系判定 | * | 乘 |
| > | 大于 | and | 與 | / | 除 |
| <= | 小于等于 | or | 或 | << | 左移位 |
| >= | 大于等于 | ! | 非 | >> | 右移位 |
puppet中的正規表達式
正規表達式在puppet中屬于非标準的資料類型，不能指派給變量，僅能用于有限的幾個接受正規表達式的地方使用，即接受使用“=～”或“！～”比對操作符的位置，通常包含case語句中的selector,以及節點名稱比對的位置；它不能傳遞給函數或用于資源屬性定義；
puppet中正規表達式的兩個特殊使用方式
(?<ENABLED OPTION>:<PATTERN>)和(?-<DISABLED OPTION>:<PATTERN>)，其中OPTIONS有i，m，x，其中i表示忽略字元大小寫；m表示把“.”點号當作換行符；x表示忽略<PATTERN>中的空白字元；比如(?imx:PATTENR)就表示忽略字元大小寫，把PATTERN中的點号當作換行符，并且忽略其中的空白字元；(?i-mx:PATTERN)表示忽略字元大小寫，不把pattern中的點号當換行符，也不忽略pattern中的空白字元；
puppet中的流程控制
所謂流程控制就是在puppet代碼中加入了條件控制語句，如if語句，case語句，selector語句，隻有滿足了條件才會執行對應的代碼；if語句文法如下
單分支
if CONDITION {
...
}
雙分支
if CONDITION {
...
} else {
...
}
多分支
if CONDITION {
...
} elsif {
...
} else{
...
}
提示：條件可以是變量，比較表達式或有傳回值的函數；
示例：通過判斷不同作業系統來安裝apache
[root@node12 ~]# cat if.pp
if $operatingsystem == "CentOS" {
$webserver = "httpd"
}elsif $operatingsystem == "Ubuntu" {
$webserver = "apache2"
}else{
$webserver = "apahce"
}
package{"$webserver":
ensure => installed,
}
[root@node12 ~]#
提示：以上資源清單表示，通過判斷$operatingsystem這個變量的值來指派$webserver的值；如果對應$operatingsystem的值為CentOS，則$webserver的值就為httpd,如果是Ubuntu $webserver的值就為apache2，如果前兩個條件都不滿足，則$webserver的值為apache；然後通過$webserver這個變量的值來安裝包；
應用資源清單
[root@node12 ~]# puppet apply -v --noop if.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.65 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1606994860'
Notice: /Stage[main]/Main/Package[httpd]/ensure: current_value absent, should be present (noop)
Notice: Class[Main]: Would have triggered 'refresh' from 1 events
Notice: Stage[main]: Would have triggered 'refresh' from 1 events
Notice: Finished catalog run in 1.24 seconds
[root@node12 ~]# puppet apply -v if.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.18 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1606994891'
Notice: /Stage[main]/Main/Package[httpd]/ensure: created
Notice: Finished catalog run in 7.99 seconds
[root@node12 ~]#
提示：從上述資訊中可以看到，目前安裝的包上httpd；原因是本機是一個centos系統；$operatingsystem這個變量是一個fact變量，主要儲存作業系統名稱；
示例：if語句中使用正規表達式
[root@node12 ~]# cat if.pp
if $operatingsystem =~/(?i-mx:(centos|redhat))/{
$webserver = "httpd"
}elsif $operatingsystem =~ /(?i-mx:(ubuntu|debian))/{
$webserver = "apache2"
}else{
$webserver = "apahce"
}
package{"$webserver":
ensure => installed,
}
[root@node12 ~]#
提示：使用正規表達式需要将正規表達式寫在“//”之間；
解除安裝httpd,應用資源清單
[root@node12 ~]# rpm -e httpd
[root@node12 ~]# puppet apply -v if.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.18 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1606995583'
Notice: /Stage[main]/Main/Package[httpd]/ensure: created
Notice: Finished catalog run in 1.86 seconds
[root@node12 ~]#
提示：可以看到應用清單并沒有報錯，提示httpd已經建立；
puppet中的case語句
文法
case CONTROL_EXPRESSION {
case1: { ... }
case2: { ... }
case3: { ... }
...
default: { ... }
}
提示：case語句和if語句的作用是類似的，case語句會從多個代碼塊中選擇一個分支執行，隻要其中任意一個case的值滿足對應的控制表達式，就執行對應case後面的代碼塊，然後退出；如果所有case都不滿足，則執行default對應的代碼塊；這裡的控制表達式可以是變量，可以是比較表達式，也可以是有傳回值的函數；case可以是字元串，正規表達式，變量，有傳回值的函數和default；
示例
[root@node12 ~]# cat case.pp
case $osfamily {
"RedHat":{ $webserver="httpd" }
/(?i-mx:debian)/:{ $webserver="apache2" }
default:{ $webserver="apache" }
}
package{"$webserver":
ensure => installed,
}
[root@node12 ~]#
解除安裝httpd，執行資源清單，看看httpd是否會被安裝？
[root@node12 ~]# rpm -e httpd
[root@node12 ~]# puppet apply -v case.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.18 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1606996150'
Notice: /Stage[main]/Main/Package[httpd]/ensure: created
Notice: Finished catalog run in 1.82 seconds
[root@node12 ~]# rpm -q httpd
httpd-2.4.6-97.el7.centos.x86_64
[root@node12 ~]#
提示：可以看到httpd可以正常的安裝；
selector語句
CONTROL_VARIABLE ? {
case1 => value1,
case2 => value2,
...
default => valueN,
}
提示：整個selector語句會被當作一個單獨的值，puppet會将控制變量按列出的次序依次與每個case進行比較，并在遇到一個比對的case後，将其值作為整個語句的值進行傳回，并忽略後面的其他case；控制變量與各case比較的方式和case語句相同，但如果沒有任何一個case與控制變量比對，puppet在編譯時将報錯，是以，我們在使用selector必須提供一個default case;控制變量隻能是一個變量或一個有傳回值的函數，不能使用表達式；各個case的值可以是字元串，變量，有傳回值的函數，正規表達式或default；
[root@node12 ~]# cat selector.pp
$pkgname = $operatingsystem ? {
/(?i-mx:(ubuntu|debian))/ => 'apache2',
/(?i-mx:(redhat|fedora|centos))/ => 'httpd',
default => 'apache',
}
package{"$pkgname":
ensure => installed,
}
[root@node12 ~]#
[root@node12 ~]# rpm -e httpd
[root@node12 ~]# puppet apply -v --noop selector.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.18 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1606997882'
Notice: /Stage[main]/Main/Package[httpd]/ensure: current_value absent, should be present (noop)
Notice: Class[Main]: Would have triggered 'refresh' from 1 events
Notice: Stage[main]: Would have triggered 'refresh' from 1 events
Notice: Finished catalog run in 0.08 seconds
[root@node12 ~]# puppet apply -v selector.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.18 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1606997889'
Notice: /Stage[main]/Main/Package[httpd]/ensure: created
Notice: Finished catalog run in 1.96 seconds
[root@node12 ~]# rpm -q httpd
httpd-2.4.6-97.el7.centos.x86_64
[root@node12 ~]#
提示：可以看到httpd通過使用selector的方式定義的資源清單一樣可以正常安裝；
puppet中的類
類是用于同于目标的一組資源，是以，它是命名的代碼塊，在某一個位置建立之後可在puppet全局使用；puppet中的類和其他程式設計語言中的類的功能很類似，puppet中的類可被繼承，也可以有子類；
類的定義文法
class class_name($var1=value1,$var2=value2){
... puppet code ...
}
提示：class是關鍵字，class_name是類名，類名隻能以小寫字母開頭，可以包含小寫字母，數字，下劃線；小括号裡是定義類的形參，每個形參可以有預設值，也可以沒有，多個形參用逗号隔開；大括号裡寫puppet的代碼；
示例：定義一個apache的類
[root@node12 ~]# cat apache.pp
class apache {
package{"httpd":
ensure => installed,
}
service{"httpd":
ensure => running,
}
}
[root@node12 ~]#
提示：以上清單中定義了一個apache的類，主要完成了安裝包和啟動服務；這裡需要注意一點，類定義好以後，如果我們不聲明類，則它不會執行，有點類似函數一樣，要向讓類執行，我們需要聲明類；
在puppet中類的聲明常用的方式有兩種，第一種是使用include關鍵字+類名；第二種是類似定義資源一樣來聲明類，其中資源類型為class，title必須為類名，這種方式通常用于有參數的類的聲明；
示例：使用include關鍵字+類名聲明類
[root@node12 ~]# cat apache.pp
class apache {
package{"httpd":
ensure => installed,
}
service{"httpd":
ensure => running,
}
}
include apache
[root@node12 ~]#
執行清單
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:26379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# puppet apply -v --noop apache.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.26 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607005266'
Notice: /Stage[main]/Apache/Service[httpd]/ensure: current_value stopped, should be running (noop)
Info: /Stage[main]/Apache/Service[httpd]: Unscheduling refresh on Service[httpd]
Notice: Class[Apache]: Would have triggered 'refresh' from 1 events
Notice: Stage[main]: Would have triggered 'refresh' from 1 events
Notice: Finished catalog run in 0.13 seconds
[root@node12 ~]# puppet apply -v apache.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.27 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607005272'
Notice: /Stage[main]/Apache/Service[httpd]/ensure: ensure changed 'stopped' to 'running'
Info: /Stage[main]/Apache/Service[httpd]: Unscheduling refresh on Service[httpd]
Notice: Finished catalog run in 0.22 seconds
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:26379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]#
提示：可以看到httpd服務已經啟動；
示例：定義帶參類
[root@node12 ~]# cat class1.pp
class dbserver ($pkg='mariadb-server',$svr='mariadb'){
package{"$pkg":
ensure => latest,
}
service{"$svr":
ensure => running,
enable => true,
}
}
if $operatingsystem == "CentOS" or $operatingsystem == "RedHat"{
case $operatingsystemmajrelease {
'7': { $pkgname='mariadb-server' $svrname='mariadb' }
default: { $pkgname='mysql-server' $svrname='mysqld' }
}
}
class{"dbserver":
pkg => $pkgname,
svr => $svrname,
}
[root@node12 ~]#
提示：以上清單主要完成對于不同版本的centos，安裝和啟動不同的服務；在centos7上安裝mariadb-server，啟動mariadb服務；其他版本的centos安裝mysql-server,啟動mysqld服務；這裡需要注意一點，聲明類中的行參不能帶$，我們可以了解為行參就是類的一個屬性；
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:26379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# puppet apply -v --noop class1.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.27 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607007562'
Notice: /Stage[main]/Dbserver/Service[mariadb]/ensure: current_value stopped, should be running (noop)
Info: /Stage[main]/Dbserver/Service[mariadb]: Unscheduling refresh on Service[mariadb]
Notice: Class[Dbserver]: Would have triggered 'refresh' from 1 events
Notice: Stage[main]: Would have triggered 'refresh' from 1 events
Notice: Finished catalog run in 0.47 seconds
[root@node12 ~]# puppet apply -v class1.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.27 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607007569'
Notice: /Stage[main]/Dbserver/Service[mariadb]/ensure: ensure changed 'stopped' to 'running'
Info: /Stage[main]/Dbserver/Service[mariadb]: Unscheduling refresh on Service[mariadb]
Notice: Finished catalog run in 2.76 seconds
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:26379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 50 *:3306 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# systemctl is-enabled mariadb.service
enabled
[root@node12 ~]#
提示：可以看到在目前系統上執行清單，啟動了mariadb；
類的繼承
類的繼承是子類繼承父類中的所有功能代碼，它可以對父類中的所有屬性進行修改，其定義文法如下
class childer_class_name inherits parent_class_name{
...puppet code ...
}
提示：子類名稱需使用完全限定名稱，比如父類是apache，子類名可以寫成apache::web;類似這種；inherits是關鍵字表示繼承之意，後面加父類名稱；
[root@node12 ~]# cat redis.pp
class redis{
package{"redis":
ensure => installed,
}
service{"redis":
ensure => running,
enable => true,
hasrestart => true,
restart => 'service redis restart',
}
}
class redis::master inherits redis {
file{"/etc/redis.conf":
ensure => file,
source => '/root/redis-master.conf',
}
Service["redis"]{
subscribe => File["/etc/redis.conf"],
restart => 'systemctl restart redis'
}
}
include redis::master
[root@node12 ~]#
提示：以上清單定義了兩個類，一個是父類名為reids，另一個為子類名為redis::master；子類繼承父類，并在其基礎上新增了file資源以及增加了service資源的訂閱關系；
本地redis-master.conf配置檔案内容
[root@node12 ~]# cat /root/redis-master.conf
bind 0.0.0.0
protected-mode yes
port 6379
tcp-backlog 511
timeout 0
tcp-keepalive 300
daemonize no
supervised no
pidfile /var/run/redis_6379.pid
loglevel notice
logfile /var/log/redis/redis.log
databases 16
save 900 1
save 300 10
save 60 10000
stop-writes-on-bgsave-error yes
rdbcompression yes
rdbchecksum yes
dbfilename dump.rdb
dir /var/lib/redis
slave-serve-stale-data yes
slave-read-only yes
repl-diskless-sync no
repl-diskless-sync-delay 5
repl-disable-tcp-nodelay no
slave-priority 100
appendonly no
appendfilename "appendonly.aof"
appendfsync everysec
no-appendfsync-on-rewrite no
auto-aof-rewrite-percentage 100
auto-aof-rewrite-min-size 64mb
aof-load-truncated yes
lua-time-limit 5000
slowlog-log-slower-than 10000
slowlog-max-len 128
latency-monitor-threshold 0
notify-keyspace-events ""
hash-max-ziplist-entries 512
hash-max-ziplist-value 64
list-max-ziplist-size -2
list-compress-depth 0
set-max-intset-entries 512
zset-max-ziplist-entries 128
zset-max-ziplist-value 64
hll-sparse-max-bytes 3000
activerehashing yes
client-output-buffer-limit normal 0 0 0
client-output-buffer-limit slave 256mb 64mb 60
client-output-buffer-limit pubsub 32mb 8mb 60
hz 10
aof-rewrite-incremental-fsync yes
[root@node12 ~]#
執行清單，看看redis是否會監聽在本機所有位址的6379端口？
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 50 *:3306 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# puppet apply -v --noop redis.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.32 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607008817'
Notice: /Stage[main]/Redis::Master/File[/etc/redis.conf]/content: current_value {md5}cb9ab7d298a50a0de20077de143e3f73, should be {md5}12e59b058c0ef61ad52bcfa2d4de58ff (noop)
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Scheduling refresh of Service[redis]
Notice: Class[Redis::Master]: Would have triggered 'refresh' from 1 events
Notice: /Stage[main]/Redis/Service[redis]/ensure: current_value stopped, should be running (noop)
Info: /Stage[main]/Redis/Service[redis]: Unscheduling refresh on Service[redis]
Notice: Class[Redis]: Would have triggered 'refresh' from 1 events
Notice: Stage[main]: Would have triggered 'refresh' from 2 events
Notice: Finished catalog run in 0.18 seconds
[root@node12 ~]# puppet apply -v redis.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.33 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607008824'
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Filebucketed /etc/redis.conf to puppet with sum cb9ab7d298a50a0de20077de143e3f73
Notice: /Stage[main]/Redis::Master/File[/etc/redis.conf]/content: content changed '{md5}cb9ab7d298a50a0de20077de143e3f73' to '{md5}12e59b058c0ef61ad52bcfa2d4de58ff'
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Scheduling refresh of Service[redis]
Notice: /Stage[main]/Redis/Service[redis]/ensure: ensure changed 'stopped' to 'running'
Info: /Stage[main]/Redis/Service[redis]: Unscheduling refresh on Service[redis]
Notice: Finished catalog run in 0.13 seconds
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:6379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 50 *:3306 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]#
提示：可以看到redis監聽在本機任何位址的6379端口；
puppet中的模闆
puppet中的模闆和ansible中的模闆功能很類似，主要用在為一些服務提供配置檔案模闆，不同于ansible中的模闆，puppet中的模闆使用的erb模闆語言，ansible使用的是jinja2模闆語言；在puppet中使用模闆的文法如下
file{'title':
ensure => file,
content => template('/PATH/TO/ERB_FILE'),
}
提示：在複制配置檔案時，指定源需使用content來指定，并且調用内建函數template來指定要複制的源檔案，通常這個源檔案就是一個模闆配置檔案；
在模闆檔案中使用内嵌的變量替換機制，其文法如下
<%= @VARIABLE_NAME %>
提示：我們需要把要替換的值用上述變量的方式代替即可；
示例：替換redis監聽位址
[root@node12 ~]# grep ^bind redis-master.conf.erb
bind <%= @ipaddress %>
[root@node12 ~]#
提示：以上内容表示bind 後面的值為ipaddress這個變量的值；這個變量是fact變量，主要用于存放本機ip位址；
定義資源清單
[root@node12 ~]# cat redis.pp
class redis{
package{"redis":
ensure => installed,
}
service{"redis":
ensure => running,
enable => true,
hasrestart => true,
restart => 'service redis restart',
}
}
class redis::master inherits redis {
file{"/etc/redis.conf":
ensure => file,
content => template('/root/redis-master.conf.erb'),
}
Service["redis"]{
subscribe => File["/etc/redis.conf"],
restart => 'systemctl restart redis'
}
}
include redis::master
[root@node12 ~]#
提示：以上清單在定義配置檔案源檔案時，指定content屬性為内建函數template調用/root/redis-master.conf.erb；表示使用這個模闆檔案覆寫/etc/redis.conf檔案内容；
執行清單，看看對應redis是否監聽在本機192.168.0.52這個位址上呢？
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:6379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 50 *:3306 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# puppet apply -v --noop redis.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.33 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607010053'
Notice: /Stage[main]/Redis::Master/File[/etc/redis.conf]/content: current_value {md5}12e59b058c0ef61ad52bcfa2d4de58ff, should be {md5}52397ae299aa46fe4103654abd62f5fd (noop)
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Scheduling refresh of Service[redis]
Notice: Class[Redis::Master]: Would have triggered 'refresh' from 1 events
Notice: /Stage[main]/Redis/Service[redis]: Would have triggered 'refresh' from 1 events
Notice: Class[Redis]: Would have triggered 'refresh' from 1 events
Notice: Stage[main]: Would have triggered 'refresh' from 2 events
Notice: Finished catalog run in 0.12 seconds
[root@node12 ~]# puppet apply -v redis.pp
Notice: Compiled catalog for node12.test.org in environment production in 0.33 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607010059'
Info: FileBucket got a duplicate file {md5}12e59b058c0ef61ad52bcfa2d4de58ff
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Filebucketed /etc/redis.conf to puppet with sum 12e59b058c0ef61ad52bcfa2d4de58ff
Notice: /Stage[main]/Redis::Master/File[/etc/redis.conf]/content: content changed '{md5}12e59b058c0ef61ad52bcfa2d4de58ff' to '{md5}52397ae299aa46fe4103654abd62f5fd'
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Scheduling refresh of Service[redis]
Notice: /Stage[main]/Redis/Service[redis]: Triggered 'refresh' from 1 events
Notice: Finished catalog run in 0.15 seconds
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 192.168.0.52:6379 *:*
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 50 *:3306 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# grep ^bind /etc/redis.conf
bind 192.168.0.52
[root@node12 ~]#
提示：可以看到對應redis已經監聽在192.168.0.52這個位址，并且配置檔案中的bing的值也是192.168.0.52；
在模闆中使用自定義變量
[root@node12 ~]# grep -Ei "^bind|port" redis-master.conf.erb
bind <%= @redis_bindip%>
port <%= @redis_port %>
[root@node12 ~]#
在資源中定義變量
[root@node12 ~]# cat redis.pp
class redis{
package{"redis":
ensure => installed,
}
service{"redis":
ensure => running,
enable => true,
hasrestart => true,
restart => 'service redis restart',
}
}
class redis::master($redis_bindip='0.0.0.0',$redis_port='6379') inherits redis {
file{"/etc/redis.conf":
ensure => file,
content => template('/root/redis-master.conf.erb'),
}
Service["redis"]{
subscribe => File["/etc/redis.conf"],
restart => 'systemctl restart redis'
}
}
class{"redis::master":
redis_port => '16379',
}
[root@node12 ~]#
提示；在該資源中聲明類時，傳遞了redis_port這個形參的值為16379，預設的redis_bindip為0.0.0.0；
執行清單，看看redis是否監聽在本機所有位址的16379端口？
[root@node12 ~]# puppet apply -v redis.pp
Warning: Config file /etc/puppet/hiera.yaml not found, using Hiera defaults
Notice: Compiled catalog for node12.test.org in environment production in 0.38 seconds
Warning: The package type's allow_virtual parameter will be changing its default value from false to true in a future release. If you do not want to allow virtual packages, please explicitly set allow_virtual to false.
(at /usr/share/ruby/vendor_ruby/puppet/type.rb:816:in `set_default')
Info: Applying configuration version '1607010599'
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Filebucketed /etc/redis.conf to puppet with sum 52397ae299aa46fe4103654abd62f5fd
Notice: /Stage[main]/Redis::Master/File[/etc/redis.conf]/content: content changed '{md5}52397ae299aa46fe4103654abd62f5fd' to '{md5}13a04cb20de2d787e0e18c1c13560cab'
Info: /Stage[main]/Redis::Master/File[/etc/redis.conf]: Scheduling refresh of Service[redis]
Notice: /Stage[main]/Redis/Service[redis]: Triggered 'refresh' from 1 events
Notice: Finished catalog run in 0.15 seconds
[root@node12 ~]# ss -tnl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 *:22 *:*
LISTEN 0 100 127.0.0.1:25 *:*
LISTEN 0 128 *:16379 *:*
LISTEN 0 128 *:27017 *:*
LISTEN 0 50 *:3306 *:*
LISTEN 0 128 :::80 :::*
LISTEN 0 128 :::22 :::*
LISTEN 0 100 ::1:25 :::*
[root@node12 ~]# grep -Ei "^bind|port" /etc/redis.conf
bind 0.0.0.0
port 16379
[root@node12 ~]#
提示：可以看到對應redis監聽在本機所有位址的16379端口，并且對應配置檔案也發生了相應的變量替換；
以上就是puppet的模闆中使用變量替換的使用方式，更多erb模闆語言的使用，請參考官方文檔https://puppet.com/docs/puppet/7.0/lang_template_erb.html#lang_template_erb；
到此puppet中的變量、正規表達式、流程控制、類和模闆的使用和示範就完了；有了這些基本程式設計元素的存在，使得puppet的資源清單變得靈活和通用，我們可以寫一個資源清單适用幾乎所有的不同的系統；
作者：Linux-1874
出處：https://www.cnblogs.com/qiuhom-1874/
本文版權歸作者和部落格園共有，歡迎轉載，但未經作者同意必須保留此段聲明，且在文章頁面明顯位置給出原文連接配接，否則保留追究法律責任的權利.
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