Class: Hiera::Backend::Simpledb_backend

Inherits:
Object
  • Object
show all
Defined in:
lib/hiera/backend/simpledb_backend.rb

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Simpledb_backend

Returns a new instance of Simpledb_backend.



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# File 'lib/hiera/backend/simpledb_backend.rb', line 8

def initialize
  begin
    require 'aws-sdk'
  rescue LoadError
    require 'rubygems'
    require 'aws-sdk'
  end

  @sdb = AWS::SimpleDB.new(Config[:simpledb])
  
  Hiera.debug("Hiera SimpleDB backend initialized")
end

Instance Method Details

#lookup(key, scope, order_override, resolution_type) ⇒ Object 



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# File 'lib/hiera/backend/simpledb_backend.rb', line 21

def lookup(key, scope, order_override, resolution_type)
  answer = Backend.empty_answer(resolution_type)
  query = Backend.parse_string(Config[:simpledb][:query], scope, { "key" => key })

  Hiera.debug("Looking up \"#{key}\" in SimpleDB Backend")
  Hiera.debug("Resolution_type: #{resolution_type}")

  # Search list of domains specified in the hierarchy section in hiera.yaml
  Backend.datasources(scope, order_override) do |source|
    Hiera.debug("Looking for simpledb domain #{source}")

    begin
      results = @sdb.domains[source].items[key].data.attributes
    rescue AWS::SimpleDB::Errors::NoSuchDomain
      Hiera.warn("Cannot find domain #{source}, skipping")
      next
    end

    next if ! results
    next if results.empty?

    Hiera.debug("Found Results: #{results.inspect}")

    # for array resolution we just append to the array whatever
    # we find, we then go onto the next file and keep adding to
    # the array
    #
    # for priority searches we break after the first found data item
    new_answer = type_conv(Backend.parse_answer(results, scope))
    case resolution_type
      when :array
        answer << new_answer
      when :hash
        answer = new_answer.merge answer
      else
        answer = new_answer
        break
    end
  end
  # The hiera backend.rb library breaks if the answer is true
  # and empty [] or {} return true, which prevents additional
  # backends from running. We don't want to prevent this so we
  # return nil instead so additional lesser priority backends
  # can run. The reason this works for :priority is that 
  # Backend.empty_answer(:priority) returns nil already
  answer = nil if answer == Backend.empty_answer(resolution_type)
  return answer
end

#type_conv(results) ⇒ Object

The simpledb aws-sdk returns attribute values as an array of values even if there is only one value. This normalizes the data type to a string if their are less than 2 array values.



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# File 'lib/hiera/backend/simpledb_backend.rb', line 73

def type_conv(results)
  new_results = Hash.new
  results.each do |k,v|
    if v.size < 2
      new_results[k] = v.to_s
    else
      new_results[k] = v
    end
  end
  return new_results
end