overriding Parameters in puppet modules - puppet

I want to override parameters of base nodes. What I want to get is a pattern like this:
# File manifests/nodes.pp
node myDefault {
class { 'my::common::puppet_setup':
service => 'enable',
pushable => 'disable',
}
# Do lots of default things ...
}
node 'myFirstNode' inherits myDefault {
# Do something ...
}
node 'mySecondNode' inherits myDefault {
class { 'my::common::puppet_setup::params':
service => 'disable',
pushable => 'enable',
}
}
I understood the the puppet documentation, i could do this by writing my module like this:
# File modules/my/manifests/common/puppet_setup.pp
class my::common::puppet_setup (
$pushable = $my::common::puppet_setup::params::pushable,
$service = $my::common::puppet_setup::params::service,
) inherits my::common::puppet_setup::params {
# package that configures puppet node
# input value validation
validate_re($pushable, ['^enable$', '^disable$', '^ignore$', ])
validate_re($service, ['^enable$', '^disable$', '^ignore$', '^cron$', ])
# setup puppet, start or disable agent, put ssh keys for push ...
}
class my::common::puppet_setup::params {
$pushable = 'enable'
$service = 'enable'
$puppetserver = 'puppet.my.site.de'
case $::osfamily {
'Debian': {
}
default: {
fail("not implemented yet for {::operatingsystem}")
}
}
}
The Documentations on puppet website says:
When a derived class is declared, its base class is automatically declared first (if it wasn’t already declared elsewhere).
But i get this error (some indentation added):
mySecondNode# puppet agent --test --environment dev_my
Error: Could not retrieve catalog from remote server:
Error 400 on SERVER: Duplicate declaration:
Class[My::Common::Puppet_setup::Params] is already declared;
cannot redeclare at /.../puppet/manifests/nodes.pp:16 on node mySecondNode
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run
I'm reading on this for a week and i guess my understanding ist totally wrong somewhere, although i used the puppetlabs ntp modules as an example.
what am i missing?

You should check Inheritance section from http://docs.puppetlabs.com/puppet/latest/reference/lang_node_definitions.html
Puppet treats node definitions like classes. It does not mash the two together and then compile the mix; instead, it compiles the base class, then compiles the derived class, which gets a parent scope and special permission to modify resource attributes from the base class.
One of the good solutions is to use roles and profiles, there's a great blog post about it:
http://garylarizza.com/blog/2014/02/17/puppet-workflow-part-2/

You can use virtual resources :
http://docs.puppetlabs.com/guides/virtual_resources.html

Related

Puppet assign class parameters in multiple places

I'm learning puppet (v6), and trying to understand how to set class parameters when a specific node needs an additional parameter, but uses the same class. Maybe a little fuzzy on the terminology, but here's what I'm working on:
MyNode1 needs sshd configured to use a banner and timeout, so using ghoneycutt-ssh, I include the ssh class with parameters:
/modules/MyModule/manifests/MySSH.pp
# Configures SSH
class MyModule::MySSH {
# Using ssh module
class { '::ssh':
sshd_client_alive_count_max => 0,
sshd_client_alive_interval => 900,
sshd_config_banner => '/etc/MyBanner.txt',
}
}
Now I have a second node MyNode2, which requires MySSH above, and also needs to disable forwarding. I started with something like this, where I define only the additional parameter in its own class:
/modules/MyModule/manifests/MySSH_Node2.pp
class MyModule::MySSH_Node2 {
class { '::ssh':
sshd_allow_tcp_forwarding => 'no',
}
}
Then define MyNode2 to include both in my site definition, hoping that puppet merges my ::ssh definitions:
/manifests/site.pp
node MyNode1 {
include MyModule::MySSH
}
node MyNode2 {
include MyModule::MySSH
include MyModule::MySSH_Node2
}
I understand that the above example doesn't work due to error Duplicate declaration: Class[Ssh]. I also tried overriding the class with a new parameter:
class MyModule::MySSH_Node2 {
Class[ssh] {
sshd_allow_tcp_forwarding => 'no',
}
}
But it seems this is not allowed either: Error: Resource Override can only operate on resources, got: Class[ssh]-Type
I'm not sure what the best way to add parameters is. I know I can create a manifest that includes all the parameters needed for this node and apply that instead, but then I end up with duplicate code everywhere.
Is there a reasonable way in modern puppet to assign and merge class parameters like this in puppet?

Puppet dependency loop when needing to notify a service from a class that first needs the service to be running

I am trying to build a module that uses the usual install->config->service pattern but with a twist. After the service starts there is more configuration done via an admin API. Unfortunately the vendor product also then requires some of the results of that API invocation to be edited into some config XML files which requires a service restart. So I have install->config->service->admin->service which is of course a dependency loop. Is there a clean way to do this? I've resorted to having to exec{'/sbin/service ... restart'} in the admin class. Not clean at all:
anchor { 'pingfederate::begin': } ->
class { '::pingfederate::install': } ->
class { '::pingfederate::config': } ~>
class { '::pingfederate::service': } ->
class { '::pingfederate::admin': } ->
anchor { 'pingfederate::end': }
and then exec {'/sbin/service pingfederate restart':}
See https://github.com/n2ygk/puppet-pingfederate

manage hosts file on Windows using Puppet

I'm trying to manage my hosts file on a Windows machine using Puppet and Hiera. My problem is that I have never really used Hiera and I'm struggling with parsing the data content into a proper format.
The relevant section in hieradata/hiera.yaml looks like this:
myhosts : [
'host1 1.2.3.4',
'host2 2.3.4.5',
'host3 3.4.5.6']
I have code that uses a host module, but it also depends on a class that I don't have, so naturally it doesn't work.
class hosts::module (
$myhosts = hiera('myhosts'),
)
{
define update_hosts {
$value = split($name,' ')
host {
"${value[0]}" : ip => "${value[1]}",
}
}
update_hosts { $myhosts :; }
}
I have tried using the file resource instead of the host resource, and also tried doing it without any class, but for some reason I am getting this error
Error: Could not retrieve catalog from remote server: Error 500 on SERVER:
Server Error: Evaluation Error: Error while evaluating a Resource Statement,
Evaluation Error: Error while evaluating a Resource Statement, Duplicate
declaration: File[C:\Temp\tmp.txt] is already declared in file
/etc/puppetlabs/code/environments/production/manifests/site.pp:4; cannot redeclare
at /etc/puppetlabs/code/environments/production/manifests/site.pp:4
at /etc/puppetlabs/code/environments/production/manifests/site.pp:4:1
at /etc/puppetlabs/code/environments/production/manifests/site.pp:10 on node puppet-agent
As you can see, it claims that I have a duplicate declaration, but the weird thing is that it says it has a problem with the same line. It thinks it's declaring the same thing twice for some reason.
This is the code I have now (I know it won't work but the error doesn't really sound related)
define hosts_update($content) {
file { 'C:\Temp\tmp.txt' :
ensure => file,
content => $content,
}
}
hosts_update{ hiera('myhosts'):
content => split($name," "),
}
Any idea how to do this right?
fixed it.
site.pp
include update_hosts
init.pp
class update_hosts::host
(
$hosts = hiera('hosts_list'),
)
{
update_host { $hosts :; }
}
host.pp
define update_host {
​
$value = split($name,' ')
​
host {
"${value[0]}" : ip => "${value[1]}",
target => "C:/Windows/System32/drivers/etc/hosts"
}
}

Puppet: Multiple manifests in module

I am trying to create Puppet module to setup my web server.
What i want - is to split configuration to logical modules (manifests by services: webserver, database, ftp etc.) But I can not figure out how to use additional manifests in init.pp
I am going to use it only with puppet apply not server-client configuration.
My text module manifest (kp/manifests/init.pp):
class kp {
include kp::testfile
}
include kp
And additional manifest (kp/manifests/testfile.pp)
define kp::testfile {
$value = template("kp/some.erb")
file { 'testfile':
path => '/tmp/my.txt',
ensure => file,
content => $value
}
}
Documentation says:
If a class is defined in a module, you can declare that class by name in any manifest. Puppet will automatically find and load the manifest that contains the class definition.
But when I run puppet apply init.pp I am getting error message
Could not find class kp::testfile for myhost.com at /myDir/puppetModules/kp/manifests/init.pp:2 on node vagrant.example.com
Facts
/myDir/puppetModules/ is in modulepath so no problems here
Puppet version v2.7.11
Ubuntu 12.04 LTS
What I am doing wrong?
Thanks in advance!
Your kp::testfile is a defined type, not a class. To use a defined type you need to declare it like:
kp::testfile { 'name': }
Try redefining kp::testfile like
class kp::testfile {
$value = template("kp/some.erb")
file { 'testfile':
path => '/tmp/my.txt',
ensure => file,
content => $value
}
}
and you may have better luck.

Puppet Can't Find Variable for Template

Just getting started with Puppet, and I'm having trouble with my first template. It should be very easy, but I can't figure it out.
I have a module "base" at
/etc/puppet/modules/base/
./manifests
./manifests/service.pp
./manifests/init.pp
./manifests/params.pp
./manifests/config.pp
./manifests/install.pp
./templates
./templates/puppet.conf.erb
There's other stuff, but it's not necessary.
base/manifests/init.pp:
class base {
include base::install, base::service, base::config, base::params
}
base/manifests/config.pp
class base::config {
include base::params
File {
require => Class["base::install"],
ensure => present,
owner => root,
group => root,
}
file { "/etc/puppet/puppet.conf":
mode => 0644,
content => template("base/puppet.conf.erb"),
require => Class["base::install"],
nofity => Service["puppet"],
}
...
base/manifests/params.pp
class base::params {
$puppetserver = "pup01.sdirect.lab"
}
Finally the interesting part of the template at base/templates/puppet.conf.erb
...
server=<% puppetserver %>
The error message:
err: Failed to parse template base/puppet.conf.erb: Could not find
value for 'puppetserver' at
/etc/puppet/modules/base/manifests/config.pp:13 on node ...
I don't get what the problem is. I've copied this part straight out of the Pro Puppet book.
Could someone show me where $puppetserver should be defined and how?
The issue is that the name "puppetserver" needs to be fully qualified so Puppet can find the value, since it's defined in a different scope to the one the template is evaluated in.
The variable is defined in base::params so can only be referred to simply as "puppetserver" in that scope. When you're evaluating the template from within base::config, you're in a different scope and so you can't refer to the variable simply by its short name. The "include" adds the other class to the catalog, but doesn't change these rules.
This means to access it, you fully qualify it with the class name: base::params::puppetserver. If you were using it in the manifest itself, this would be $base::params::puppetserver. You'll see similar examples in Pro Puppet in the ssh::config and ssh::service classes where it refers to "ssh_service_name" in the params class (pages 43-45).
To access the variable in a template it's a bit different, use scope.lookupvar("base::params::puppetserver"). Taking your full example and adding a missing equals sign (to output the value) in the template:
...
server=<%= scope.lookupvar("base::params::puppetserver") %>
There's a bit more information about scoping on the Scope and Puppet as of 2.7 page.
(Edit: looks like it's listed on the confirmed errata page too with the same solution.)
Answer #1 is technically correct, but results in very verbose templates.
You can shorten them by bringing variable values from other classes into your own class scope:
class base::config {
include base::params
$puppetserver = $base::params::puppetserver
...
}
And then use them in your template as expected:
server=<% puppetserver %>
You could also use inherits:
class puppet::config inherits puppet::params {
....
In this way you don't have to define $puppetserver again in this class.

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