I would like to know if it is possible to access a parameter from a class being instantiated using the create_resources function. I want to use that parameter in other class to conditionally install some things or not.
This is my scenario:
define myResource($myParam) { ... }
create_resources(myResource, $hashResources)
$hashResources = { "MyResource1" : { "myParam" : 1 },
"MyResource2" : { "myParam" : 2 }
}
myFancyPuppetClass($nameOfResource) {
if(******myParam from the resource defined with name $nameOfResource in the same catalog******) { ... }
}
Is this possible? If it is, how can I do the reference? Thank you!
Since the resources you are attempting to create are defined types, and the parameters in a defined resource are not accessible, this is not possible in the latest version of Puppet.
See a previous answer of mine regarding accessing parameters in defined resources for an alternative.
Related
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?
Is it possible to somehow create an arbitrary attribute from a variable? Here is what I am trying to achieve.
How I currently do it (now deprecated in 3.0.0):
resource "aws_lb_listener_rule" "example" {
condition {
field = var.condition_field
values = var.condition_values
}
}
The new syntax requires a nested block with the condition field. But my condition is stored in a variable:
resource "aws_lb_listener_rule" "example" {
condition {
var.condition_field {
values = var.condition_values
}
}
}
Is it possible to somehow create an arbitrary attribute from a variable?
or: Can I store a nested attribute block in a variable?
Background on my question: I am currently trying to upgrade from 2.70.0 to 3.0.0 and there are quite a few breaking changes in my system. One of them includes the aws_lb_listener_rule. If it is not possible to create the attribute from the variable I would have to either pin the version or change the module API used by a ton of projects.
It actually seems like it is not possible to do that. The closes thing I have found that allows me to use 3.0.0 without changing my module variables and with that all the Terraform scripts that use it are dynamic conditional blocks.
dynamic "condition" {
for_each = var.field == "path-pattern" ? [var.field] : []
content {
path_pattern {
values = var.patterns
}
}
}
This is repeated for all possible var.field values.
How to overwrite defined type in nodes.pp? I want to able to set custom domain using nodes.pp. Case Default isn't an option.
I'm using puppet 6.0..
The following method doesn't work. It says Could not find declared class resolv::resolv_config.
It looks like it used to work in 3.0 according to this answer.
nodes.pp
node "test001" {
class { 'resolv::resolv_config':
domain => "something.local",
}
}
modules/resolv/manifests/init.pp
class resolv {
case $hostname {
/^[Abc][Xyz]/: {
resolv:resolv_config { 'US':
domain => "mydomain.local",
}
}
}
}
define resolv::resolv_config($domain){
file { '/etc/resolv.conf':
content => template("resolv/resolv.conf.erb"),
}
}
resolv.conf.erb
domain <%= #domain %>
There are a couple of problems here, but the one causing the "could not find declared class" error is that you are using the wrong syntax for declaring a defined type. Your code should be something like this:
node "test001" {
resolv::resolv_config { 'something.local':
domain => "something.local",
}
}
There are examples of declaring defined types in the documentation, https://puppet.com/docs/puppet/latest/lang_defined_types.html.
Once you get that working, you'll find another problem, in that this definition
define resolv::resolv_config($domain){
file { '/etc/resolv.conf':
content => template("resolv/resolv.conf.erb"),
}
}
will cause a error if you try to declare more than one resolv::resolv_config, because they will both try to declare the /etc/resolv.conf file resource. You almost certainly wanted to use a file_line resource.
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
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.