Class: Cfhighlander::Util::CloudFormation

Inherits:
Object
  • Object
show all
Defined in:
lib/util/cloudformation.util.rb

Class Method Summary collapse

Class Method Details

.collect_output_values(template) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 328

def self.collect_output_values(template)
  output_vals = {}
  template.subcomponents.each do |sub_component|
    # we collect outputs only from inlined components
    model = sub_component.component_loaded.cfn_model_raw
    model['Outputs'].each do |name, value|
      output_vals[sub_component.component_loaded.name] = {} unless output_vals.key? sub_component.component_loaded.name
      output_vals[sub_component.component_loaded.name][name] = value['Value']
    end if model.key? 'Outputs'
  end
  return output_vals
end

.collect_replacements(component, template, output_values) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 240

def self.collect_replacements(component, template, output_values)
  replacements = {}

  # collect replacements for inlined components
  template.subcomponents.each do |sub_component|
    next unless sub_component.inlined
    component_loaded = sub_component.component_loaded
    replacements[component_loaded.name] = []
    sub_stack_def = component.cfn_model_raw['Resources'][sub_component.cfn_name]
    next unless sub_stack_def['Properties'].key? 'Parameters'
    params = sub_stack_def['Properties']['Parameters']
    params.each do |param_name, param_value|
      # if param value is hash, we may find output values
      # these should be replaced with inlined values
      if param_value.is_a? Hash
        outval_refs = find_outval_refs(param_value)
        outval_refs.each do |out_ref|
          # replacement only takes place if
          # source component is inlined as well
          # if source component is not inlined
          # it's output won't be collected
          source_sub_component = template.subcomponents.find {|sc| sc.component_loaded.name == out_ref[:component]}

          # if source component is not inlined we can replacement as-is
          next unless source_sub_component.inlined
          search = { 'Fn::GetAtt' => [
              out_ref[:component],
              "Outputs.#{out_ref[:outputName]}"
          ] }
          replacement = output_values[out_ref[:component]][out_ref[:outputName]]
          if param_value == search
            param_value = replacement
          else
            # parameter value may be deeper in the structure, e.g.
            # member of Fn::If intrinsic function
            node_replace(
                param_value,
                search,
                replacement
            )
          end if output_values.key? out_ref[:component]

        end
      end
      replacements[component_loaded.name] << {
          search: { 'Ref' => param_name },
          replace: param_value
      }
    end

  end

  # collect replacements to be performed on parameters of non-inlined components
  # that are referencing inlined components
  replacements[component.name] = []
  template.subcomponents.each do |sub_component|
    next if sub_component.inlined
    sub_stack_def = component.cfn_model_raw['Resources'][sub_component.cfn_name]
    next unless sub_stack_def['Properties'].key? 'Parameters'
    params = sub_stack_def['Properties']['Parameters']
    params.each do |param_name, param_value|
      if param_value.is_a? Hash
        outval_refs = find_outval_refs(param_value)

        # component is NOT inlined and has out references to components that MAY be inlined
        outval_refs.each do |out_ref|
          component_name = out_ref[:component]
          ref_sub_component = template.subcomponents.find {|sc| sc.name == component_name}

          if ref_sub_component.nil?
            raise Cfhighlander::Error, "unable to find outputs from component #{component_name} reference by parameters in component #{sub_component.name}"
          end

          if ref_sub_component.inlined
            # out refs here need to be replaced with actual values
            replacement = output_values[out_ref[:component]][out_ref[:outputName]]
            replacements[component.name] << {
                search: { 'Fn::GetAtt' => [component_name, "Outputs.#{out_ref[:outputName]}"] },
                replace: replacement
            }
          end
        end
      end
    end
  end
  return replacements
end

.find_outval_refs(tree, outval_refs = []) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 214

def self.find_outval_refs(tree, outval_refs = [])
  tree.each do |key, val|

    # if we have located get att, it may be output value
    if key == 'Fn::GetAtt'
      if val.is_a? Array and val.size == 2
        if val[1].start_with? 'Outputs.'
          component = val[0]
          output = val[1].split('.')[1]
          outval_refs << { component: component, outputName: output }
        end
      end
    elsif val.is_a? Hash or val.is_a? Array
      # however we may also find output deeper in the tree
      # example being FnIf(condition, out1, out2)
      find_outval_refs(val, outval_refs)
    end

  end if tree.is_a? Hash

  tree.each do |element|
    find_outval_refs(element, outval_refs)
  end if tree.is_a? Array
  return outval_refs
end

.flatten_key_names(component, template) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 460

def self.flatten_key_names(component, template)
  flatten_namespace('Conditions', component, template)
  Debug.debug_dump_cfn(template, 'flat.conditions')

  flatten_namespace('Mappings', component, template)
  Debug.debug_dump_cfn(template, 'flat.mappings')

  flatten_namespace('Resources', component, template)
  Debug.debug_dump_cfn(template, 'flat.resources')
end

.flatten_namespace(element_type, component, template) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 52

def self.flatten_namespace(element_type, component, template)
  if component.cfn_model_raw.key? element_type
    keys_taken = component.cfn_model_raw[element_type].keys
  else
    keys_taken = []
  end
  template.subcomponents.each do |sub_component|
    next unless sub_component.inlined
    model = sub_component.component_loaded.cfn_model_raw
    model[element_type].keys.each do |key|
      if keys_taken.include? key
        candidate = "#{sub_component.component_loaded.name}#{key}"
        counter = 1
        while keys_taken.include? candidate
          candidate = "#{sub_component.component_loaded.name}#{key}#{counter}"
          counter = counter + 1
        end
        actual_key = candidate
        # we need to replace all as
        # resources can reference conditions
        # outputs can and will reference resources
        model[element_type][actual_key] = model[element_type][key]
        model[element_type].delete(key)
        case element_type
        when 'Resources'
          rename_resource(model, key, actual_key)
        when 'Mappings'
          rename_mapping(model, key, actual_key)
        when 'Conditions'
          rename_condition(model, key, actual_key)
        when 'Outputs'
          # outputs are not effecting anything within the same template
        end
        keys_taken << actual_key
      else
        keys_taken << key
      end
    end if model.key? element_type
  end
end

.flattenCloudformation(args = {}) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 12

def self.flattenCloudformation(args = {})

  component = args.fetch(:component)
  template = component.highlander_dsl

  # make sure all mappings, resources and conditions
  # are named uniquely in all of the templates
  flatten_key_names(component, template)
  Debug.debug_dump_cfn(template, 'namespace_flat')

  # collect output values
  output_values = collect_output_values(template)
  Debug.debug_dump(output_values, 'outputs')

  # collect referenced parameters and convert to replacements
  component_replacements = collect_replacements(component, template, output_values)
  Debug.debug_dump(component_replacements, 'replacements')

  # apply replacements in referenced templates
  process_replacements(component, template, component_replacements)
  Debug.debug_dump_cfn(template, 'transformed')

  # inline all of the resources
  inline_resources(component, template)

  # remove substacks
  remove_inlined_component_stacks(component, template)

  # return inlined model
  return component.cfn_model_raw
end

.inline_elements(element_name, component, template) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 106

def self.inline_elements(element_name, component, template)
  parent_model = component.cfn_model_raw
  template.subcomponents.each do |sub_component|
    next unless sub_component.inlined
    model = sub_component.component_loaded.cfn_model_raw
    model[element_name].each do |resource, value|
      if sub_component.conditional
        # If the resource already has a conditon we need to combine it with the stack condition
        if element_name == 'Conditions'
          value = { "Fn::And" => [{"Condition" => sub_component.condition}, value]}
        end
        # Adds the condition to the inlined resource if it doesn't already have a condition
        if element_name == 'Resources' || element_name == 'Outputs'
          value['Condition'] = sub_component.condition unless value.has_key?('Condition')
        end
      end
      # effective extraction of child resource into parent
      # allows for line components to use - or _ in the component name
      # and still generate valid references
      safe_resource_name = resource.gsub('-','').gsub('_','')
      unless element_name == 'Outputs' && resource.end_with?('CfTemplateUrl')
        parent_model[element_name] = {} unless parent_model.key? element_name
        parent_model[element_name][safe_resource_name] = value
      end
    end if model.key? element_name
  end
end

.inline_resources(component, template) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 93

def self.inline_resources(component, template)
  inline_elements('Conditions', component, template)
  inline_elements('Mappings', component, template)
  inline_elements('Resources', component, template)

  # outputs are renamed AFTER all of the other processing
  # has been done, as outputs are referenced. Only
  # outputs of inlined components are renamed
  flatten_namespace('Outputs', component, template)
  Debug.debug_dump_cfn(template, 'flat.outputs')
  inline_elements('Outputs', component, template)
end

.node_replace(tree, search, replacement) ⇒ Object

if hash is treated as collection of tree structures where each key in Hash is root of the tree and value is subtree replace hash subtree with another subtree



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# File 'lib/util/cloudformation.util.rb', line 346

def self.node_replace(tree, search, replacement)
  if tree.is_a? Hash
    tree.each do |root, subtree|
      if subtree == search
        tree[root] = replacement
      elsif subtree.is_a? Hash or subtree.is_a? Array
        node_replace(subtree, search, replacement)
      end
    end
  elsif tree.is_a? Array
    tree.each do |element|
      if element == search
        tree[tree.index element] = replacement
      elsif element.is_a? Hash or element.is_a? Array
        node_replace(element, search, replacement)
      end
    end
  end
end

.process_replacements(component, template, component_replacements) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 134

def self.process_replacements(component, template, component_replacements)

  # replacement processing is done from least to most dependant component
  dependency_sorted_subcomponents = template.subcomponents.sort {|sc1, sc2|
    sc1_params = component.cfn_model_raw['Resources'][sc1.cfn_name]['Properties']['Parameters']
    sc2_params = component.cfn_model_raw['Resources'][sc2.cfn_name]['Properties']['Parameters']
    outval_refs_sc1 = find_outval_refs(sc1_params)
    outval_refs_sc2 = find_outval_refs(sc2_params)

    # if sc1 is dependant on sc2,
    # sc2 param outval refs should have sc1 output
    # and vice versa
    sc1_depends_sc2 = if outval_refs_sc1.find{|oref| oref[:component] == sc2.cfn_name}.nil? then false else true end
    sc2_depends_sc1 = if outval_refs_sc2.find{|oref| oref[:component] == sc1.cfn_name}.nil? then false else true end

    if (sc1_depends_sc2 and sc2_depends_sc1)
      raise StandardError, "Components #{sc1.cfn_name} and #{sc2.cfn_name} have circular dependency!!"
    end
    if sc1_depends_sc2 then
      +1
    elsif sc2_depends_sc1 then
      -1
    else
      0
    end
  }

  # process replacements in order from least dependant to
  # most dependant
  dependency_sorted_subcomponents.each_with_index do |sub_component, index|
    next unless sub_component.inlined
    component_name = sub_component.component_loaded.name
    if component_replacements.key? component_name
      if sub_component.component_loaded.cfn_model_raw.key? 'Outputs'
        outputs_apriori = duplicate(sub_component.component_loaded.cfn_model_raw['Outputs'])
      else
        outputs_apriori = {}
      end
      component_replacements[component_name].each do |replacement|
        node_replace(
            sub_component.component_loaded.cfn_model_raw,
            replacement[:search],
            replacement[:replace]
        ) # some of the component outputs may be changed and thus replacements need be updated
      end
      iteration_index = 2
      outputs_apriori.each do |out_name, out_value|
        value_after_transform = sub_component.component_loaded.cfn_model_raw['Outputs'][out_name]
        # value of the output was changed by replacement
        unless out_value == value_after_transform
          # for all downstream dependant components
          propagated_update_index = index + 1
          while propagated_update_index < dependency_sorted_subcomponents.size
            pc_name = dependency_sorted_subcomponents[propagated_update_index].component_loaded.name
            component_replacements[pc_name].each do |replacement|
              # replacements for dependant component needs to be updated as well
              replace = replacement[:replace]

              if out_value['Value'] == replace
                replacement[:replace] = value_after_transform['Value']
              else
                node_replace(replacement[:replace], out_value['Value'], value_after_transform['Value'])
              end

            end if component_replacements.include? pc_name
            propagated_update_index += 1
          end
          Debug.debug_dump(component_replacements, "replacements.#{iteration_index}")
          iteration_index += 1
        end
      end
    end
  end

  # process replacements on component itself
  component_replacements[component.name].each do |replacement|
    node_replace(component.cfn_model_raw, replacement[:search], replacement[:replace])
  end
end

.remove_inlined_component_stacks(component, template) ⇒ Object 



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# File 'lib/util/cloudformation.util.rb', line 44

def self.remove_inlined_component_stacks(component, template)
  model = component.cfn_model_raw
  template.subcomponents.each do |sub_component|
    next unless sub_component.inlined
    model['Resources'].delete(sub_component.cfn_name)
  end
end

.rename_condition(tree, search, replacement) ⇒ Object

rename cloudformation condition in cfn model



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# File 'lib/util/cloudformation.util.rb', line 409

def self.rename_condition(tree, search, replacement)
  # conditions can be referenced by Fn::If and Condition => cond
  tree.keys.each do |k|
    v = tree[k]
    if k == 'Fn::If' and v[0] == search
      tree[k] = [replacement, v[1], v[2]]
    end

    if k == 'Condition' and v == search
      tree[k] = replacement
    end

    if v.is_a? Array or v.is_a? Hash
      rename_condition(v, search, replacement)
    end
  end if tree.is_a? Hash

  tree.each do |element|
    rename_condition(element, search, replacement)
  end if tree.is_a? Array

end

.rename_mapping(tree, search, replacement) ⇒ Object

rename cloudformation mapping in cfn model



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# File 'lib/util/cloudformation.util.rb', line 390

def self.rename_mapping(tree, search, replacement)
  tree.keys.each do |k|
    v = tree[k]
    if k == 'Fn::FindInMap' and v[0] == search
      tree[k] = [replacement, v[1], v[2]]
    end

    if v.is_a? Array or v.is_a? Hash
      rename_mapping(v, search, replacement)
    end
  end if tree.is_a? Hash

  tree.each do |element|
    rename_mapping(element, search, replacement)
  end if tree.is_a? Array

end

.rename_resource(tree, search, replacement) ⇒ Object

rename cloudformation resource in model



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# File 'lib/util/cloudformation.util.rb', line 367

def self.rename_resource(tree, search, replacement)
  tree.keys.each do |k|
    v = tree[k]
    if k == 'Ref' and v == search
      tree[k] = replacement
    end

    if k == 'Fn::GetAtt' and v[0] == search
      tree[k] = [replacement, v[1]]
    end

    if v.is_a? Array or v.is_a? Hash
      rename_resource(v, search, replacement)
    end
  end if tree.is_a? Hash

  tree.each do |element|
    rename_resource(element, search, replacement)
  end if tree.is_a? Array

end

.value_replace(tree, search, replacement) ⇒ Object

Replace single value in tree structure (represented) either as Hash or Array with another value



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# File 'lib/util/cloudformation.util.rb', line 434

def self.value_replace(tree, search, replacement)
  if tree.is_a? Hash
    tree.keys.each do |root|
      subtree = tree[root]
      if root == search
        tree[replacement] = subtree
        tree.delete(root)
      end
      if subtree == search
        tree[root] = replacement
      end
      if subtree.is_a? Hash or subtree.is_a? Array
        value_replace(subtree, search, replacement)
      end
    end
  elsif tree.is_a? Array
    tree.each do |element|
      if element == search
        tree[tree.index element] = replacement
      elsif element.is_a? Hash or element.is_a? Array
        value_replace(element, search, replacement)
      end
    end
  end
end