Passing Parameter as Array to Puppet Modules

Trey_Dockendorf · August 22, 2011, 3:22am

I've seen previous discussions on the inability to pass an array or
hash as a parameter, and am exploring ways to work around this. I
have very little Ruby programming experience, and am hoping someone
here may have done something similar.

Here's a hash I currently have defined for a node…

backuppc_db_dumps =  {
    &#39;example&#39; =&gt; {
            &#39;backup_dir&#39;    =&gt; &#39;/var/www/example.com&#39;,
            &#39;databases&#39; =&gt; &#39;example&#39;,
            &#39;dump_dir&#39;  =&gt; &#39;/backups/example-sqldumps&#39;,
    },
    &#39;general&#39; =&gt; {
            &#39;backup_dir&#39;    =&gt; &#39;/etc&#39;,
            &#39;databases&#39;     =&gt; &#39;mysql&#39;,
            &#39;dump_dir&#39;  =&gt; &#39;/backups/misc-sqldumps&#39;,
    },
}

the string looks like so…

backuppc_db_dumps = "{'general'=>{'dump_dir'=>'/backups/misc-
sqldumps', 'databases'=>'mysql', 'backup_dir'=>'/etc'},
'anth'=>{'dump_dir'=>'/backups/example-sqldumps', 'datab
ases'=>'example', 'backup_dir'=>'/var/www/example.com'}}"

I have successfully tested using a custom Puppet function to convert
the string back into a hash. The problem is that the only way I've
been able to turn that back into a hash is using "eval", which I'd
prefer not to use.

I've tried converting that string to YAML and then to hash with no
luck. I can't find a way to represent the information in a single
string that can be manipulated with YAML.load() or any of the other
various methods that have been suggested around the net.

Are there any changes post Foreman-0.3 that are going to change the
way parameters can be defined for nodes? I'd be happy to help work in
a change to Foreman if it's not already been done in a development
version.

Thanks

Trey

Nan_Liu · August 22, 2011, 5:10am

> I've seen previous discussions on the inability to pass an array or
> hash as a parameter, and am exploring ways to work around this. I
> have very little Ruby programming experience, and am hoping someone
> here may have done something similar.
>
> Here's a hash I currently have defined for a node…
>
> backuppc_db_dumps = {
> 'example' => {
> 'backup_dir' => '/var/www/example.com',
> 'databases' => 'example',
> 'dump_dir' => '/backups/example-sqldumps',
> },
> 'general' => {
> 'backup_dir' => '/etc',
> 'databases' => 'mysql',
> 'dump_dir' => '/backups/misc-sqldumps',
> },
> }
>
> the string looks like so…
>
> backuppc_db_dumps = "{'general'=>{'dump_dir'=>'/backups/misc-
> sqldumps', 'databases'=>'mysql', 'backup_dir'=>'/etc'},
> 'anth'=>{'dump_dir'=>'/backups/example-sqldumps', 'datab
> ases'=>'example', 'backup_dir'=>'/var/www/example.com'}}"
>
> I have successfully tested using a custom Puppet function to convert
> the string back into a hash. The problem is that the only way I've
> been able to turn that back into a hash is using "eval", which I'd
> prefer not to use.

You can choose json or yaml.

> I've tried converting that string to YAML and then to hash with no
> luck. I can't find a way to represent the information in a single
> string that can be manipulated with YAML.load() or any of the other
> various methods that have been suggested around the net.

In Puppet Enterprise 1.2, the functions in stdlib can serve as stop
gap until Dashboard/Foreman fully support array/hash. Specifically
parseyaml and parsejson:

github.com

puppetlabs/puppetlabs-stdlib/blob/master/lib/puppet/parser/functions/parseyaml.rb

#
# parseyaml.rb
#
module Puppet::Parser::Functions
  newfunction(:parseyaml, :type => :rvalue, :doc => <<-DOC
    This function accepts YAML as a string and converts it into the correct
    Puppet structure.

    The optional second argument can be used to pass a default value that will
    be returned if the parsing of YAML string have failed.
  DOC
             ) do |arguments|
    raise ArgumentError, 'Wrong number of arguments. 1 or 2 arguments should be provided.' unless arguments.length >= 1
    require 'yaml'

    begin
      YAML.load(arguments[0]) || arguments[1] # rubocop:disable Security/YAMLLoad : using YAML.safe_load causes the code to break
      # in ruby 1.9.3 Psych::SyntaxError is a RuntimeException
      # this still needs to catch that and work also on rubies that
      # do not have Psych available.

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github.com

puppetlabs/puppetlabs-stdlib/blob/master/lib/puppet/parser/functions/parsejson.rb

#
# parsejson.rb
#
module Puppet::Parser::Functions
  newfunction(:parsejson, :type => :rvalue, :doc => <<-DOC
    This function accepts JSON as a string and converts it into the correct
    Puppet structure.

    The optional second argument can be used to pass a default value that will
    be returned if the parsing of YAML string have failed.
  DOC
             ) do |arguments|
    raise ArgumentError, 'Wrong number of arguments. 1 or 2 arguments should be provided.' unless arguments.length >= 1

    begin
      PSON.load(arguments[0]) || arguments[1]
    rescue StandardError => e
      raise e unless arguments[1]
      arguments[1]
    end

This file has been truncated. show original

Thanks,

Nan

···

On Sun, Aug 21, 2011 at 8:22 PM, treydock wrote:

Trey_Dockendorf · August 22, 2011, 3:36pm

The parseyaml function was exactly what I was trying to achieve, but
my problem is how to represent my current hashes in the correct format
to be used with YAML.load.

Could you possibly give me an example of what a string accepted by
YAML.load would look like?

Thanks

Trey

···

On Aug 22, 12:10 am, Nan Liu wrote: > On Sun, Aug 21, 2011 at 8:22 PM, treydock wrote: > > I've seen previous discussions on the inability to pass an array or > > hash as a parameter, and am exploring ways to work around this. I > > have very little Ruby programming experience, and am hoping someone > > here may have done something similar. > > > Here's a hash I currently have defined for a node... > > > backuppc_db_dumps = { > > 'example' => { > > 'backup_dir' => '/var/www/example.com', > > 'databases' => 'example', > > 'dump_dir' => '/backups/example-sqldumps', > > }, > > 'general' => { > > 'backup_dir' => '/etc', > > 'databases' => 'mysql', > > 'dump_dir' => '/backups/misc-sqldumps', > > }, > > } > > > the string looks like so... > > > backuppc_db_dumps = "{'general'=>{'dump_dir'=>'/backups/misc- > > sqldumps', 'databases'=>'mysql', 'backup_dir'=>'/etc'}, > > 'anth'=>{'dump_dir'=>'/backups/example-sqldumps', 'datab > > ases'=>'example', 'backup_dir'=>'/var/www/example.com'}}" > > > I have successfully tested using a custom Puppet function to convert > > the string back into a hash. The problem is that the only way I've > > been able to turn that back into a hash is using "eval", which I'd > > prefer not to use. > > You can choose json or yaml. > > > I've tried converting that string to YAML and then to hash with no > > luck. I can't find a way to represent the information in a single > > string that can be manipulated with YAML.load() or any of the other > > various methods that have been suggested around the net. > > In Puppet Enterprise 1.2, the functions in stdlib can serve as stop > gap until Dashboard/Foreman fully support array/hash. Specifically > parseyaml and parsejson: > > https://github.com/puppetlabs/puppetlabs-stdlib/blob/master/lib/puppe...https://github.com/puppetlabs/puppetlabs-stdlib/blob/master/lib/puppe... > > Thanks, > > Nan