Puppet: Class Ordering / Containment - always wrong order - puppet

I read a lot about ordering puppet classes with containment (iam using Puppet 6). But it still does not work for me in one case. Maybe my english is not good enough and i miss something. Maybe somebody know what iam doing wrong.
I have a profile to installing a puppetserver (profile::puppetserver). This profile has three sub-classes which I contain within the profile::puppetserver
class profile::puppetserver(
) {
contain profile::puppetserver::install
contain profile::puppetserver::config
contain profile::puppetserver::firewall
}
That works fine for me. Now I want to expand this profile and install PuppetDB. For this, i use the puppetdb module from puppet forge:
So what i do is add profile::puppetserver::puppetdb and the contain to the profile::puppetserver
class profile::puppetserver::puppetdb(
) {
# Configure puppetdb and its underlying database
class { 'puppetdb': }
# Configure the Puppet master to use puppetdb
class { 'puppetdb::master::config': }
}
When i provision my puppetserver first and add the profile::puppetserver::puppetdb after it, puppetdb installs and everything works fine.
If I add it directly with contain, and provisioning everything at once, it crashes. It's because the puppetdb module is installed randomly during my master server installs (and also the postgresql server and so on). That ends in my puppetserver is not running and my puppetdb generate no local ssl certificates and the service doesn't comes up.
What i try first:
I installed the puppetdb Package in my profile::puppetserver::puppetdb directly and use the required flag. It works when i provision all at once.
class profile::puppetserver::puppetdb (
) {
Package { 'puppetdb':
ensure => installed,
require => Class['profile::puppetserver::config']
}
}
So i think i could do the same in the code above:
class profile::puppetserver::puppetdb(
) {
# Configure puppetdb and its underlying database
class { 'puppetdb':
require => Class['profile::puppetserver::config']
}
# Configure the Puppet master to use puppetdb
class { 'puppetdb::master::config':
require => Class['profile::puppetserver::config']
}
}
But this does not work...
So i read about puppet class containment and ordering by chains. So i did this in my profile::puppetserver
class profile::puppetserver(
) {
contain profile::puppetserver::install
contain profile::puppetserver::config
contain profile::puppetserver::firewall
contain profile::puppetserver::puppetdb
Class['profile::puppetserver::install'] ->
Class['profile::puppetserver::config'] ->
Class['profile::puppetserver::firewall'] ->
Class['profile::puppetserver::puppetdb']
}
But it still does not have any effect... he still starts to install postgresql and the puppetdb package during my "puppetserver provisioning" in the install, config, firewall steps.
How i must write the ordering, that all things from the puppetdb module, which i call in profile::puppetserver::puppetdb, only starts when the rest of the provisioning steps are finished?
I really don't understand it. I think maybe it haves something to do with the fact, that i declare classes from the puppetdb module inside of profile::puppetserver::puppetdb and not the directly Resource Type. Because when i use the Package Resource Type with the Require Flag, it seems to work. But i really don't know how to handle this. I think there must be a way or?

I think maybe it haves something to do with the fact, that i declare
classes from the puppetdb module inside of
profile::puppetserver::puppetdb and not the directly Resource Type.
Because when i use the Package Resource Type with the Require Flag, it
seems to work.
Exactly so.
Resources are ordered with the class or defined-type instance that directly declares them, as well as according to ordering parameters and instructions applying to them directly.
Because classes can be declared multiple times, in different places, ordering is more complicated for them. Resource-like class declarations such as you demonstrate (and which you really ought to avoid as much as possible) do not imply any particular ordering of the declared class. Neither do declarations via the include function.
Class declarations via the require function place a single-ended ordering constraint on the declared class relative to the declaring class or defined type, and declarations via the contain function place a double-ended ordering constraint similar to that applying to all resource declarations. The chaining arrows and ordering metaparameters can place additional ordering constraints on classes.
But i really dont know how to handle this. I think there must be a way or?
Your last example shows a viable way to enforce ordering at the level of profile::puppetserver, but its effectiveness is contingent on each of its contained classes taking the same approach for any classes they themselves declare, at least where those third-level classes must be constrained by the order of the second-level classes. This appears to be where you are falling down.
Note also that although there is definitely a need to order some things relative to some others, it is not necessary or much useful to try to enforce an explicit total order over all resources. Work with the lightest hand possible, placing only those ordering constraints that serve a good purpose.

Related

Puppet: Declaring a class with inheritance

I currently have two classes that I created within /etc/puppet/modules/params/manifests/init.pp
class modulename ($variable_name = 'Any string') inherits modulename::params{
file { '/tmp/mytoplevelclass.sh' :
mode => '644',
ensure => 'present',
content => $variable_name
}
}
class modulename::params{
}
However, I am having an issue declaring these classes in /etc/puppet/manifests/site.pp. Currently, I have it written as
node default { #client
class { 'modulename':}
class { 'modulename::params':}
}
I know that this is incorrect because when I run puppet agent -t on the client I get an error stating
Could not find declared class modulename at /etc/puppet/manifests/site.pp
I have tried several different configurations and still am unsure on what to do.
Puppet determines the file in which it expects to find a class's definition based on the class's fully-qualified name. The docs go into it in some detail; in particular, you should review the Module Fundamentals. (I am guessing that you are on Puppet 3, but the details I am about to discuss are unchanged in Puppet 4.)
Supposing that /etc/puppet/modules is a directory in your modulepath, it is a fine place to install (or write) your modulename module, as indeed you indicate you are doing. If it is not in your module path, then you'll want either to move your module to a directory in the module path, or to add that directory to the module path. I assume that you will resolve any problem of this sort via the latter alternative, so that /etc/puppet/modules/modulename is a valid module directory.
Now, class 'modulename' is a bit special in that its name is also a module name; as such, it should be defined in /etc/puppet/modules/modulename/manifests/init.pp. Class modulename::params, on the other hand, should follow the normal pattern, being defined in /etc/puppet/modules/modulename/manifests/params.pp. I anticipate that Puppet will find the definitions if you put the definitions in the correct files.
Bonus advice:
Use include-like class declarations in your node blocks, not resource-like declarations
Your node blocks probably should not declare modulename::params at all

Collect values from other puppet classes

I'm trying to implement automatic monitoring using nagios/icinga and puppet.
Hosts and basic services are working but now I want to implement different checks for services based on hostgroups. While I could setup the hostgroups in hiera I want to be able to do the following:
Apply a class for each service (like ssh, http) which only "exports" a hostgroup-name (like "ssh-servers" and "http-servers"
and also apply a base class which "collects" these names, joins them to a string and exports a nagios_host resource like this:
##nagios_host { $::fqdn:
ensure => present,
use => "generic-host",
alias => $::hostname,
address => $::ipaddress,
hostgroups => $hostgroups, # this should be something like "ssh-servers, http-servers"
}
I'm just starting with puppet and looked at virtual resources and exported resources but I'm not sure how to apply this correctly. Is this even possible?
The export/import paradigm does not lend itself well to this type of data gathering. If you want to take advantage of it, you will need to define resource types that Just Work when gathered on the Nagios server from all the agent catalogs.
Your mileage might very well increase if you try and rely on PuppetDB queries instead. You get much more control this way.

Global resources in Puppet

Is it possible to add a global resource?
I have about 1000 nodes with different configurations and now I want to install a package on every single node. Can it be done in site.pp?
I have a default node, but from what I can tell it is only for unrecognised nodes so I don't think this is the way to change it.
This will depend on the way you have written your puppet manifests. If you have a class included on every node, then you could add the definition to that.
You could user hiera to allow you to customise the default packages on a per machine basis. If you had a module called siteconfig, then you could could create a class something like;
modules/siteconfig/manifests/init.pp
class siteconfig {
include siteconfig::defaults
package{$::siteconfig::params::packages:
ensure => 'present',
}
}
modules/siteconfig/manifests/params.pp
class siteconfig::params(
$packages = []
) {
validate_array($packages)
}
and then define siteconfig::params::packages in hiera as an array of packages to be installed by default. This means that you could easily add more default packages by editing the array in hiera, and you could customise it on a per-host basis.
Bonus points if you work out how to use create_resources instead!

Reusing Puppet Defined Type Parameter in Other Defined Type

Lets say I want to define a set of resources that have dependencies on each other, and the dependent resources should reuse parameters from their ancestors. Something like this:
server { 'my_server':
path => '/path/to/server/root',
...
}
server_module { 'my_module':
server => Server['my_server'],
...
}
The server_module resource both depends on my_server, but also wants to reuse the configuration of it, in this case the path where the server is installed. stdlib has functions for doing this, specifically getparam().
Is this the "puppet" way to handle this, or is there a better way to have this kind of dependency?
I don't think there's a standard "puppet way" to do this. If you can get it done using the stdlib and you're happy with it, then by all means do it that way.
Personally, if I have a couple defined resources that both need the same data I'll do one of the follow:
1) Have a manifest that creates both resources and passes the data both need via parameters. The manifest will have access to all data both resources need, whether shared or not.
2) Have both defined resources look up the data they need in Hiera.
I've been leaning more towards #2 lately.
Dependency is only a matter of declaring it. So your server_module resource would have a "require => Server['my_server']" parameter --- or the server resource would have a "before => Server_module['my_module']".

resource ordering synchronization issue "->" doesn't work?

I have encounter really weird behaviour which goes against what I have learned, tutorial says etc. So I would be glad if someone could explain why that is happening.
I have a role module which is made up of composition of profiles (role-profile pattern). My role consists:
class role::lab_prg_c2_dn inherits lab_prg_c2 {
class { 'profile::cluster_data_node':
namenode_fqdn => $role::lab_prg_c2::namenode_fqdn,
secondarynamenode_fqdn => $role::lab_prg_c2::secondarynamenode_fqdn,
}
->
class{'bigdatasolution':}
}
First class installs technology and second one installs our components and items which are build on top of technology. Hence the technology need to be installed first, thats the reason for "->" dependency. However this seems to me doesn't work correctly. As components from class 'bigdatasolution' are installed somewhere before the class profile::cluster_data_node finishes.
I tried to use require => Class['profile::cluster_data_node'] but that doesn't make any difference!
The content of class{'bigdatasolution':} :
class bigdatasolution {
$hdfs_default_conf = '/usr/local/hadoop.hdfs.conf'
$hbase_default_conf = '/usr/local/hadoop.hbase.conf'
include symlinks
include bdjar
}
Symlinks - create symlinks for the configuration installed in class profile::cluster_data_node and are not directly managed - it will be presented when actually specified package get installed.
bdjar - add our jar to a technology library so content is as follows:
class bigdatasolution::bdjar {
file { "/usr/lib/hadoop/lib/bigdata-properties.jar":
ensure => present,
mode => 0644,
group => 'root',
owner => 'root',
source => "puppet:///modules/bigdatasolution/bigdata-properties.jar"
}
}
I even tried to put require => "technologycalClass" here but that doesn't help either.
Can someone please help me understand what's wrong and how that should be solved properly?
I Using puppet 3 and ordering is specified explicetly - so no arbitrary ordering set by puppet should happen.
Thanks
If your 'profile::cluster_data_node' class 'includes' other classes/modules they will have no dependency ordering with the 'bigdatasolution' class.
I see you actually do include symlinks and bdjar. Basically every piece of ordering you want to have in puppet, you need to write explicitly.
Here you should replace the include statements with require, that way the class cluster_data_node will require the other two modules to complete before it says it has completed. Include is a pretty lose way of importing things in puppet and in my opinion is best to just avoid it and go with explicit require statements instead.
TL;DR: included modules have no transitive ordering; required modules do.

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