Class: CloudFormationTool::CloudFormation

Inherits:
Object
  • Object
show all
Defined in:
lib/cloud_formation_tool/cloud_formation.rb,
lib/cloud_formation_tool/cloud_formation/stack.rb,
lib/cloud_formation_tool/cloud_formation/lambda_code.rb,
lib/cloud_formation_tool/cloud_formation/nested_stack.rb,
lib/cloud_formation_tool/cloud_formation/cloud_front_distribution.rb

Defined Under Namespace

Modules: CloudFrontDistribution, CloudFrontInvalidation Classes: LambdaCode, NestedStack, Stack

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path) ⇒ CloudFormation

Returns a new instance of CloudFormation.



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 15

def initialize(path)
  log "Loading #{path}"
  @path = path
  @path = "#{@path}/cloud-formation.yaml" if File.directory? @path
  @path = "#{@path}.yaml" if !File.exist? @path and File.exist? "#{@path}.yaml"
  @basedir = File.dirname(@path)
  @compiled = false
  @params = nil
  begin
    text = File.read(@path)
    # remove comments because white space seen between comments can seriously psych Psych
    text.gsub!(/^#.*\n/s,'')
    text = fixShorthand(text)
    @data = YAML.load(text).to_h
  rescue Psych::SyntaxError => e
    e.message =~ /line (\d+) column (\d+)/
    lines = text.split "\n"
    raise CloudFormationTool::Errors::AppError, "Error parsing #{path} at line #{e.line} column #{e.column}:\n" +
      "#{lines[e.line-1]}\n" +
      "#{(' ' * (e.column - 1 ))}^- #{e.problem} #{e.context}"
  rescue Errno::ENOENT => e
    raise CloudFormationTool::Errors::AppError, "Error reading #{path}: #{e.message}"
  end
end

Instance Attribute Details

#basedir ⇒ Object (readonly)

Returns the value of attribute basedir.



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 13

def basedir
  @basedir
end

Class Method Details

.parse(path) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 9

def self.parse(path)
  CloudFormation.new(path)
end

Instance Method Details

#compile(parameters = nil) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 40

def compile(parameters = nil)
  @params = parameters unless parameters.nil?
  embed_includes
  @data = load_files(@data)
end

#each ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 202

def each
  compile['Parameters'].each do |name, param|
    yield name, param['Default']
  end
end

#embed_includes ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 95

def embed_includes
  (@data.delete(@data.keys.find{|k| k.start_with? 'Include'}) || []).each do |path|
    realpath = "#{@basedir}/#{path}"
    cfile_key = File.dirname(realpath).gsub(%r{/(.)}){|m| $1.upcase }.gsub(/\W+/,'')
    rewrites = Hash.new
    CloudFormation.new(realpath).compile.each do |category, catdata|
      # some categories are meta-data that we can ignore from includes
      next if %w(AWSTemplateFormatVersion Description).include? category
      
      case category
      when "Parameters"
        (@data[category]||={}).each do |name, param|
          if catdata.has_key? name
            next if param['Default'] == catdata[name]['Default']
             
            if catdata[name].has_key?('Override') and catdata[name]['Override'] == false
              catdata.delete(name)
            else
              newname = "#{cfile_key}z#{name}"
              log "Rewriting conflicting parameter #{name} (='#{catdata[name]['Default']}') to #{newname}"
              catdata[newname] = catdata.delete name
              rewrites[name] = newname
            end
          else
            @data[category][name] = param
          end
        end
      else
        # warn against duplicate entities, resources or outputs
        (@data[category] ||= {}).keys.each do |key|
          if catdata.has_key? key
            raise CloudFormationTool::Errors::AppError, "Error compiling #{path} - duplicate '#{category}' item: #{key}"
          end 
        end
        catdata = fixrefs(catdata, rewrites)
      end
      
      # add included properties
      @data[category].merge! catdata
    end
  end
end

#embed_includes_future ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 85

def embed_includes_future
  (@data.delete(@data.keys.find{|k| k.start_with? 'Include'}) || []).each do |path|
    case path
    when Hash
    when String
      embed_included_path path
    end
  end
end

#fixrefs(data, rmap) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 65

def fixrefs(data, rmap)
  case data
  when Hash
    data.inject({}) do |h,(k,v)|
      h[k] = if k == "Ref"
        rmap[v] || v
      else
        fixrefs(v,rmap)
      end
      h
    end
  when Array
    data.collect do |item|
      fixrefs(item, rmap)
    end
  else
    return data
  end
end

#fixShorthand(text) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 51

def fixShorthand(text)
  text.gsub(/(?:(\s*)([^![:space:]]+))?(\s+)!(\w+)/) do |match|
    case $4
    when *%w(Base64 FindInMap GetAtt GetAZs ImportValue Join Select Sub Split
      And Equals If Not Or)
      ($2.nil? ? "" : "#{$1}#{$2}\n#{$1} ") + "#{$3}\"Fn::#{$4}\":"
    when 'Ref'
      "#{$1}#{$2}\n#{$1} #{$3}#{$4}:"
    else
      match
    end
  end
end

#load_files(data, restype = nil) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 161

def load_files(data, restype = nil)
  case data
  when Array
    data.collect { |data| load_files(data, restype) }
  when Hash
    # remember the current resource type
    restype = data['Type'] if restype.nil? and data.key?('Type')
    data.inject({}) do |dict, (key, val)|
      dict[key] = case restype
        when 'AWS::AutoScaling::LaunchConfiguration'
          if (key == "UserData") and (val["File"]) 
            # Support LaunchConfiguration UserData from file
            CloudInit.new("#{@basedir}/#{val["File"]}").to_base64
          elsif (key == "UserData") and (val["FileTemplate"]) 
            # Support LaunchConfiguration UserData from file with substitutions
            { "Fn::Base64" => { "Fn::Sub" => CloudInit.new("#{@basedir}/#{val["FileTemplate"]}").compile } }
          else
            load_files(val, restype)
          end
        when 'AWS::Lambda::Function'
          if key == 'Code'
            LambdaCode.new(val, self, data['Runtime']).to_cloudformation
          else
            load_files(val, restype)
          end
        when 'AWS::CloudFormation::Stack'
          if key == 'Properties' and val.key?('Template')
            NestedStack.new(val, self).to_cloudformation
          else
            load_files(val, restype)
          end
        else
          load_files(val, restype)
      end
      dict
    end
  else
    data
  end
end

#resolveVal(value) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 138

def resolveVal(value)
  case value
  when Hash
    if value.key? 'Ref'
      if @params.nil?
        # no parameters, we are probably in a sub template, just return the ref and hope
        # a parent template has what it takes to resolve the ref
        value
      else # parameters are set for this template - we can try to resolve
        res = @params[value['Ref']] || ((@data['Parameters']||{})[value['Ref']] || {})['Default']
        if res.nil?
          raise CloudFormationTool::Errors::AppError, "Reference #{value['Ref']} can't be resolved"
        end
        res
      end
    else
      raise CloudFormationTool::Errors::AppError, "Value #{value} is not a valid value or reference"
    end
  else
    value
  end
end

#to_yaml(parameters = {}) ⇒ Object 



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# File 'lib/cloud_formation_tool/cloud_formation.rb', line 46

def to_yaml(parameters = {})
  @params = parameters
  compile.to_yaml
end