(Sorry, long post, and .. I'm replying via copy & paste from Google Groups)
On Wed, 15 Sep 2010 19:59:35 -0700 (PDT), Patrick wrote: >Sounds like a job for Augeas or puppet-concat. I think puppet_concat = >would be a better fit. >Augeas: http://docs.puppetlabs.com/references/stable/type.html#augeas >puppet_concat: http://github.com/ripienaar/puppet-concat= Thank you Patrick for the suggestions. I explored puppet_concat further, and found that it: - Requires files to be split into several pieces to be useful i.e. the head, body, then tail. - Leaves fragment files (turds?) on client filesystems, however well-categorized they may be. So I became motivated to see if I could develop an improved solution that did the string processing server-side, then returned the finished results to the client. I wrote a custom type (for Puppet 0.25.5) named "concat". In short, you can make line-based contributions scattered across many places, and the concat type will join them together with newlines and *somehow* make the resulting string available. My first use-case is configuring an SNMP daemon. But it's incomplete: - Resulting concatenated strings are not available from within the Puppet DSL. - I'm not confident concatenation is being done before Puppet ultimately provides the resulting string values for use. The code is at the bottom of this message. Let's look at how to use it. Although unnecessary, I envisioned the resulting concatenated strings would be defined in arbitrary scopes, like this: # In file modules/jvm/manifests/init.pp : concat { "JVM SNMP": variable => "snmp::snmpd_conf_contributions", lines => "proxy -m ${mib_file} -v 2c -c ${snmp_community} localhost:1161 .1.3.6.1.4.1.42.2.145" , before => Class["snmp"], } # In file modules/postgres/manifests/init.pp : concat { "PostgreSQL postmaster SNMP": variable => "snmp::snmpd_conf_contributions", lines => "proc postmaster", before => Class["snmp"], } In one ideal, the custom type would: 1. Gather all lines for each given distinct variable, 2. Perform concatenation, joining lines with UNIX newlines "\n" into a single string value, and 3. Set the appropriate variable in the appropriate scope to the final value Continuing the above example, $snmp::snmpd_conf_contributions would have the value "proxy -m ${mib_file} -v 2c -c ${snmp_community} localhost:1161 .1.3.6.1.4.1.42.2.145\nproc postmaster". Note that the lines could be reversed; this implementation doesn't consider the order of multiple concat resources, but if the lines param is an array, order within that array is preserved. Now, the value could be used: # In file modules/snmp/manifests/init.pp: file { "/etc/snmpd.conf": content => "blah blah\n<%= snmpd_conf_contributions %>\nblah blah", # Easily extends to the use of template() } # Or, using some mechanism from within an ERB document: <%= concatenated_value('snmpd_conf_contributions') %> Well, even after studying type.rb, scope.rb, setvar.rb, and friends, I don't know how to finish the implementation. Given my current level of understanding, this is about as far as I can take the code today. Any hints, suggestions, ideas? Even without scoping? Can this be made to work at all? Better yet, I hope some enterprising soul takes it from here ^_^ Ty * I sense that modifying variable values, or appending to the value of variables out-of-scope, might be perceived as being counter to the spirit of Puppet. But this approach would cause me less pain and give greater control over the contents of configuration files in a way Augeas & other methods don't. Although, it might all be subjective, or I might be missing something .. It might even be a Bad Idea. ---- 8< ---- modules/common/lib/puppet/type/concat.rb ---- 8< ---- module Puppet # Note: The following global variables cause namespace pollution $concat_raw_map = {} # Maps identifiers to arrays of a mix of strings and arrays of strings $concat_processed_map = {} # Maps identifiers to each of their final string representations $concat_finalized = false $concat_instance_count = 0 $concat_total_rule_count = 0 newtype(:concat) do @doc = "Sets the string value of *TODO* to the concatenation of all contributors. With multiple concat resources, order of appearance in the final concatenated string is unspecified. Multiple content values are concatenated by being joined together with UNIX newline \\n characters. The implementation is partially patterned after iptables.rb." newparam(:name) do desc "The name of this concat resource. Does not influence concatenation behavior." isnamevar end newparam(:variable) do desc "Content is concatenated to the value of this variable identifier, typed as a string." end newparam(:lines) do desc "A string, or an array of strings, the value of which is concatenated to the value of the variable identifier. In the case of an array of strings, line order is preserved." end def initialize(args) super(args) $concat_total_rule_count += 1 # Memorize these lines var = value(:variable).to_s if not $concat_raw_map.has_key?(var) # Create a new entry for this variable $concat_raw_map[var] = [] end lines = value(:lines) $concat_raw_map[var].unshift(lines) debug("Concatenate to #{var}: '#{[lines].flatten * '\', \''}'") # Enable flatten to handle even a non-array type end def evaluate $concat_instance_count += 1 if $concat_instance_count == $concat_total_rule_count self.finalize unless self.finalized? end return super end # finalize() runs once, after all concat resources have been declared. # For each identifier in the raw map, do the concatenation operation, and set the appropriate variable *TODO* to this value. def finalize # Any of the supplied :lines parameter values may have been arrays themselves, so flatten them $concat_processed_map = Hash[* $concat_raw_map.map{|k, v| [k, v.flatten * "\n"]}.flatten] $concat_processed_map.each { |k, v| debug("Assign #{k} = '#{v}'") } $concat_finalized = true end def finalized? if defined? $concat_finalized return $concat_finalized else return false end end # Reset class variables to their initial value def self.clear $concat_raw_map = {} $concat_processed_map = {} $concat_finalized = false $concat_instance_count = 0 $concat_total_rule_count = 0 super end end end -- You received this message because you are subscribed to the Google Groups "Puppet Users" group. 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