Advanced Puppet Topics. Ken Barber Professional Services Engineer

Transcription

1 Advanced Puppet Topics Ken Barber Professional Services Engineer

2 aka My favourite puppet features

3 Topics Standalone Puppet Ruby DSL extlookup dotty output External Node Classification Puppetdocs

4 Standalone Puppet

5 Standalone Puppet The Puppet Domain Specific Language (DSL) is a language that can be used standalone Works like any other script Requires no infrastructure

6 Example 1 create_file.pp: #!/usr/bin/env puppet file { /tmp/example1.out : content => Example 1\n,

7 Example 1 # chmod +x create_file.pp #./create_file.pp notice: /Stage[main]//File[/tmp/example1.out]/ensure: defined content as '{md58a0a86c394456fa d8e1419f94' notice: Finished catalog run in 0.08 seconds # cat /tmp/example1.out Example 1 #

8 Example 2 setup_mysql.pp: #!/usr/bin/env puppet package { 'mysql-server': ensure => installed, file { '/etc/my.cnf': source => 'my.cnf', notify => Service['mysql'], service { 'mysql': ensure => running, enable => true, require => Package['mysql-server'],

9 Example 2 # chmod +x setup_mysql.pp #./setup_mysql.pp notice: /Stage[main]//Package[mysql-server]/ensure: ensure changed 'purged' to 'present' notice: /Stage[main]//File[/etc/mysql/my.cnf]/ensure: defined content as '{md5b82b1ec5fa04a e94e5cda845e' notice: /Stage[main]//Service[mysql]: Triggered 'refresh' from 1 events notice: Finished catalog run in seconds #

10 Example 3 # puppet apply -e "file{'/tmp/foo':content=>\"foo\n\"" notice: /Stage[main]//File[/tmp/foo]/ensure: defined content as '{md5d3b07384d113edec49eaa6238ad5ff00' notice: Finished catalog run in 0.08 seconds # cat /tmp/foo foo #

11 Use Cases Boot strapping Puppet on a machine that has minimal facilities Development work Running Puppet in master-less mode

12 Ruby DSL

13 Why Puppet DSL? It s declarative so its ideal for configuration management We can constrain the behaviour to only configuration management You don t need to know ruby to start, and its simpler to learn then most languages

14 Why Ruby DSL? Allows you to extend Puppet beyond normal Puppet DSL No constraints Prototype new ideas that can potentially become Puppet DSL later

15 How to use Ruby DSL Puppet now recognises the.rb extension standalone_script.pp -> standalone_script.rb manifests/site.pp -> manifests/site.rb <module>/manifests/init.pp -> <module>/ manifests/init.rb import extras.pp -> import extras.rb

16 How to use the Ruby DSL standalone_script.rb: #!/usr/bin/env puppet hostclass :foo do notice ["foo"] end node "default" do include foo end

17 Ruby DSL - Nodes # Puppet DSL node "default" { notice( Default node ) # Ruby DSL node "default" do notice[ Default node ] end

18 Ruby DSL - Classes # Puppet DSL class foo { notice("foo") node "default" { include foo # Ruby DSL hostclass :foo do notice ["foo"] end node "default" do include foo end

19 Ruby DSL - Functions # Puppet DSL node "default" { notice("function output") # Ruby DSL node "default" do notice ["Function output"] end # Ruby DSL - alternative node "default" do call_function notice, ["Function output"] end

20 Ruby DSL - Resources # Puppet DSL define myresource() { notice($name) node "default" { myresource {"resource_output": # Ruby DSL define "myresource" do notice [@name] end node "default" do create_resource :myresource, "resource_output" end

21 Ruby DSL - Variables # Puppet DSL node "default" { $myvar = "value is here" notice($myvar) # Ruby DSL node "default" do scope.setvar("myvar", "value is here") a = scope.lookupvar("myvar") notice [a] end

22 Mysql Example require 'mysql' hostclass :packages do # Connect to mysql conn = Mysql.new('localhost', 'user', 'password', 'cmdb') # Obtain a list of mysql packages (and versions) pkgs = conn.query('select * from packages') # Create a package resource for each package defining the version # for each pkgs.each_hash { p package p['name'], :ensure => p['version'] conn.close end node 'default' do include 'packages' end

23 Ruby DSL - Further Information Wiki Article: Ruby_Dsl Google puppet ruby dsl

24 extlookup()

25 Config vs Code Node Classifiers External Node Classifiers Large lookup tables in Puppet DSL External data like CSV tables

26 Usage # Configure extlookup data directory and precedence $extlookup_datadir = "." $extlookup_precedence = [ "%{fqdn", "location_%{location", "county_%{country", "common" ] # Fetch extlookup and print the results notice(extlookup("snmp_trap_host"))

27 Example - common common.csv: snmp_trap_host, #./example1.pp notice: Scope(Class[main]): notice: Finished catalog run in 0.01 seconds #

28 Example - country common.csv: snmp_trap_host, country_de.csv: snmp_trap_host, #./example1.pp notice: Scope(Class[main]): notice: Finished catalog run in 0.01 seconds #

29 Example - location common.csv: snmp_trap_host, country_de.csv: snmp_trap_host, location_holidayinn.csv: snmp_trap_host, #./example1.pp notice: Scope(Class[main]): notice: Finished catalog run in 0.01 seconds #

30 dotty output

31 dotty output Puppet defines every artifact as a resources Resources are related to each other through dependency Internally, these dependencies are mapped as a graph These graphs can be output in dotty format

32 dotty: Tools Graphviz - open source, very flexible, widely used Gephi - free, java based, powerful graph support Omnigraffle - commercial, more then just graphs

33 dotty output Traditional Way: puppet --noop --graph --graphdir /vagrant/graphs relationships.pp With new Puppet Interfaces: puppet catalog --format dot find localhost > ~/Desktop/catalog.dot

34 dotty Example 1 file { '/files': ensure => directory file { '/files/001.txt': ensure => file, content => '001', require => File['/files'],

35 dotty Example 1

36 dotty Example 2 package { myapp : ensure => installed file { /etc/myapp.cfg : content => template( myapp/myapp.cfg ), require => Package[ myapp ], service { myapp : ensure => running, require => File[ /etc/myapp.cfg ],

37 dotty Example 2

38 dotty Example 3 package { 'myapp': ensure => installed, file { '/etc/myapp1.cfg': content => 'myapp1', require => Package['myapp'], file { '/etc/myapp2.cfg': content => 'myapp2', require => Package['myapp'], service { 'myapp': ensure => running,

39 dotty Example 3

40 dotty Example 3 package { 'myapp': ensure => installed, file { '/etc/myapp1.cfg': content => 'myapp1', require => Package['myapp'], notify => Service[ myapp ], file { '/etc/myapp2.cfg': content => 'myapp2', require => Package['myapp'], notify => Service[ myapp ], service { 'myapp': ensure => running,

41 dotty Example 3

42 dotty - big example

43 External Node Classification

44 Nodes - normally node app1 { $snmp_trap_host = traps.puppetlabs.com $dns_server = include tomcat include myapp include resolver include snmpd node db1 { $snmp_trap_host = traps.puppetlabs.com $dns_server = $mysql_dbs = [ db1 ] include mysql include resolver include snmpd

45 Why ENC? Allows you to store node definitions outside of Puppet Provides Configuration / Code separation You can provide information from another information store such as a CMDB or asset database

46 Configuration /etc/puppet/puppet.conf: [main] external_nodes = /usr/local/bin/puppet_node_classifier node_terminus = exec

47 API First argument passed to the external script is the hostname The script must return valid YAML on standard out The script returns 0 for success or non-zero to indicate the node is not found

48 Puppet: YAML Returned node app1 { $snmp_trap_host = traps.puppetlabs.com $dns_server = YAML: include tomcat include myapp include resolver include snmpd --- environment: production parameters: snmp_trap_host: traps.puppetlabs.com dns_server: classes: - tomcat - myapp - resolver - snmpd Text

49 Good ENC s Puppet Dashboard The Foreman

50 Puppetdocs

51 Puppetdocs Works in a similar way to ruby docs or Perl docs Documentation should be close to code Can be setup to auto-generate code from VCS using CI tools like Jenkins Supports markdown format

52 Format - Class # Description of class. # # == Variables # # None # # == Examples # # include myclass # # == Authors # # Ken Barber <ken@puppetlabs.com> # # == Copyright # # Copyright 2011 Puppetlabs Inc, unless otherwise noted. # class myclass {...

53 Format - Resource # Description of resource. # # == Parameters # # [param1] # Parameter 1 does something magical # # == Examples # # myresource { myname : # param1 => value, # # # == Authors # # Ken Barber <ken@puppetlabs.com> # # == Copyright # # Copyright (C) 2011 Puppetlabs Inc, unless otherwise noted. # define myresource($param1) {...

54 Example Webserver: puppetdoc

55 Any Questions?