Templates
TOPICS
-
static vs dynamic files
-
templates
-
ERB Syntax
server.dev.xml
server.stg.xml
server.prod.xml
memory = 128mb
port = 8081
memory = 4gb
port = 8888
memory = 16gb
port = 8080
static file
dev
stage
prod
server.xml.erb
memory = <%= @memory %>
port = <%= @port %>
template
node
hiera
module
server.xml
ERB
ERB = EMbedded ruby
Erubis
-
Contains text with dynamic ruby code
-
uses tags to mark dynamic code
ERB Tags
<%=
%>
<%
%>
group exercise
templatize tomcat
configs
-
Create a Template -
Define Parameters -
Update file resource to use template function
steps
we always start with the original configs. Good point to start with s copy over the original config as is and start converting it into a template by replacing parameter values
Create file structure to store the templates
- Create a director modules/tomcat/templates
- Create a ERB template at modules/tomcat/templates/tomcat.conf.erb
- Copy over the contents of the original tomcat.conf. You could use the link below as a sample content
TOMCAT_CFG_LOADED="1"
JAVA_HOME="/usr/lib/jvm/jre"
JAVA_OPTS="-Xms64m -Xmx128m -XX:MaxPermSize=128M -Djava.security.egd=file:/dev/./urandom"
CATALINA_BASE="/usr/share/tomcat"
CATALINA_HOME="/usr/share/tomcat"
JASPER_HOME="/usr/share/tomcat"
CATALINA_TMPDIR="/var/cache/tomcat/temp"
TOMCAT_USER="tomcat"
SECURITY_MANAGER="false"
SHUTDOWN_WAIT="30"
SHUTDOWN_VERBOSE="false"
CATALINA_PID="/var/run/tomcat.pid"
file: modules/tomcat/templates/tomcat.conf.erb
group exercise
Templatize
- start replacing the values with template variables
- template variables are enclosed in the marker tags
- define the sane defaults in tomcat::params class
TOMCAT_USER="tomcat"
SHUTDOWN_WAIT="30"
TOMCAT_USER="<%= @user %>"
SHUTDOWN_WAIT="<%= @shutdown_wait %>"
becomes
$shutdown_wait = 30
params.pp
TIP : Its always useful to define the params first in params.pp before replacing the values in the template with ERB tags. That way, you would not have to go figure what were the default values, as once replaces, those values are gone. Its also easir to just copy over the params back as template variables.
pro tip
exercise
Exercise
Update the following properties in tomcat.conf in the template, and define the defaults in params.pp
- TOMCAT_CFG_LOADED
- JAVA_HOME
- xms
- xmx
- maxpermsize
- CATALINA_BASE
- JASPER_HOME
- CATALINA_TMPDIR
- SECURITY_MANAGER
- SHUTDOWN_VERBOSE
- CATALINA_PID
TOMCAT_CFG_LOADED=<%= @tomcat_cfg_loaded %>
JAVA_HOME=<%= @java_home %>
JAVA_OPTS="-Xms<%= @xms %> -Xmx<%= @xmx %> -XX:MaxPermSize=<%= @maxpermsize %> <%= @java_opts %>"
CATALINA_BASE=<%= @catalina_base %>
CATALINA_HOME=<%= @catalina_home %>
JASPER_HOME=<%= @jasper_home %>
CATALINA_TMPDIR=<%= @catalina_tmpdir %>
TOMCAT_USER=<%= @user %>
SECURITY_MANAGER=<%= @security_manager %>
SHUTDOWN_WAIT=<%= @shutdown_wait %>
SHUTDOWN_VERBOSE=<%= @shutdown_verbose %>
CATALINA_PID=<%= @catalina_pid %> file: modules/tomcat/templates/tomcat.conf.erb
solution
class tomcat::params {
$color = 'white'
$car = 'figo'
$user = 'tomcat'
$group = 'tomcat'
$config_path = '/etc/tomcat/tomcat.conf'
$packages = [ 'tomcat', 'tomcat-webapps' ]
$service_name = 'tomcat'
$service_state = running
$tomcat_cfg_loaded = "1"
$java_home = "/usr/lib/jvm/jre"
$xms = "64m"
$xmx = "128m"
$maxpermsize = "128M"
$java_opts = " -Djava.security.egd=file:/dev/./urandom"
$catalina_base = "/usr/share/tomcat"
$catalina_home = "/usr/share/tomcat"
$jasper_home = "/usr/share/tomcat"
$catalina_tmpdir = "/var/cache/tomcat/temp"
$security_manager = "false"
$shutdown_wait = "30"
$shutdown_verbose = "false"
$catalina_pid = "/var/run/tomcat.pid"
}tomcat::params class
solution
source => 'puppet:///modules/tomcat/tomcat.conf',
update file: modules/tomcat/manifests/config.pp
to
group exercise
content => template('tomcat/tomcat.conf.erb'),
from
file: modules/tomcat/manifests/config.pp
group exercise
class tomcat::config inherits tomcat{
file { $::tomcat::config_path:
#source => 'puppet:///modules/tomcat/tomcat.conf',
content => template('tomcat/tomcat.conf.erb'),
owner => $::tomcat::user,
group => $::tomcat::group,
mode => '0644',
notify => Service['tomcat']
}
}APPLY
group exercise