Puppet Function: couchdblookup

Defined in:
lib/puppet/parser/functions/couchdblookup.rb
Function type:
Ruby 3.x API

Overview

couchdblookup() ⇒ Any

*Retrieve values from couchdb*

Takes a CouchDB URL and a key as argument, and returns the value. If the key isn’t found, it will return a parse error, or the value specified in the optional 3rd argument.

Example:

$couchdburl = 'http://localhost:5984/users'
couchdblookup("${couchdburl}/joe", 'ssh_pubkey')
couchdblookup("${couchdburl}/bob", 'ssh_pubkey', 'invalid-key')

If the “vagrantbox” fact is set, it will always return “undef” (assuming the couchdb server is unreachable from inside a vagrant box).

Returns:

  • (Any) 


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# File 'lib/puppet/parser/functions/couchdblookup.rb', line 9

newfunction(:couchdblookup, :type => :rvalue, :doc => <<-EOS
*Retrieve values from couchdb*

Takes a CouchDB URL and a key as argument, and returns the value. If the key
isn't found, it will return a parse error, or the value specified in the
optional 3rd argument.

*Example:*

  $couchdburl = 'http://localhost:5984/users'
  couchdblookup("${couchdburl}/joe", 'ssh_pubkey')
  couchdblookup("${couchdburl}/bob", 'ssh_pubkey', 'invalid-key')

If the "vagrantbox" fact is set, it will always return "undef" (assuming the
couchdb server is unreachable from inside a vagrant box).

EOS
) do |args|
  require 'json'
  require 'open-uri'

  raise Puppet::ParseError, ("couchdblookup(): wrong number of arguments (#{args.length}; must be 2 or 3)") unless args.length.between?(2, 3)

  url = args[0]
  key = args[1]
  default = args[2] if args.length >= 3

  begin
    if exist?('vagrantbox') && lookupvar('vagrantbox') == true
      Puppet.send(:warning, "Bypassing couchdb lookup because 'vagrantbox' fact is defined. couchdblookup() will not return what you expect !")
      return default ? default : :undef
    end
  rescue Puppet::ParseError
    # do nothing
  end

  begin
    json = JSON.parse(open(URI.parse(url)).read)
  rescue OpenURI::HTTPError => error
    raise Puppet::ParseError, "couchdblookup(): fetching URL #{url} failed with status '#{error.message}'"
  rescue Timeout::Error => error
    raise Puppet::ParseError, "couchdblookup(): connection to couchdb server timed out: '#{error.message}'"
  rescue Errno::ECONNREFUSED => error
    raise Puppet::ParseError, "couchdblookup(): connection to couchdb server failed: '#{error.message}'"
  rescue JSON::ParserError => error
    raise Puppet::ParseError, "couchdblookup(): failed to parse JSON received from couchdb: '#{error.message}'"
  rescue StandardError => error
    raise Puppet::ParseError, "couchdblookup(): something unexpected happened: '#{error.inspect}'"
  end

  result = nil

  if json.has_key?("rows")

    if json['rows'].length > 1
      arr = json['rows'].collect do |x|
        x[key] if x.is_a?(Hash) and x.has_key?(key)
      end
      arr.compact!
      result = arr unless arr.empty?

    elsif json['rows'].length == 1
      hash = json['rows'].pop
      result = hash[key] if hash.is_a?(Hash)
    end

  elsif json.has_key?(key)
    result = json[key]
  end

  if result.nil?
    default or raise Puppet::ParseError, "couchdblookup(): key '#{key}' '#{result}' not found in JSON object at '#{url}' !"
  else
    result
  end

end