Module: AutoStacker24::Preprocessor

Defined in:
lib/autostacker24/template_preprocessor.rb

Class Method Summary collapse

Class Method Details

.adjust_tags_for_asg(tags) ⇒ Object 



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# File 'lib/autostacker24/template_preprocessor.rb', line 72

def self.adjust_tags_for_asg(tags)
  asg_tags = tags.inject([]) { |t,element| t << element.dup }

  asg_tags.each {|(tag)|
    tag["PropagateAtLaunch"] = "true"
  }

  asg_tags
end

.preprocess(template, tags = nil) ⇒ Object 



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# File 'lib/autostacker24/template_preprocessor.rb', line 8

def self.preprocess(template, tags = nil)
  if template =~ /^\s*\/{2}\s*/i
    template = template.gsub(/(\s*\/\/.*$)|(".*")/) {|m| m[0] == '"' ? m : ''} # replace comments
    template = preprocess_json(JSON(template))
    template = preprocess_tags(template, tags).to_json
  end
  template
end

.preprocess_json(json) ⇒ Object 



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# File 'lib/autostacker24/template_preprocessor.rb', line 82

def self.preprocess_json(json)
  if json.is_a?(Hash)
    json.inject({}){|m, (k, v)| m.merge(k => preprocess_json(v))}
  elsif json.is_a?(Array)
    json.map{|v| preprocess_json(v)}
  elsif json.is_a?(String)
    preprocess_string(json)
  else
    json
  end
end

.preprocess_string(s) ⇒ Object 



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# File 'lib/autostacker24/template_preprocessor.rb', line 94

def self.preprocess_string(s)
  parts = tokenize(s).map do |token|
    case token
      when '@@' then '@'
      when /^@/ then {'Ref' => token[1..-1]}
      else token
    end
  end

  # merge neighboured strings
  parts = parts.reduce([])do |m, p|
    if m.last.is_a?(String) && p.is_a?(String)
      m[-1] += p
    else
      m << p
    end
    m
  end

  if parts.length == 1
    parts.first
  else # we need a join construct
    {'Fn::Join' => ['', parts]}
  end
end

.preprocess_tags(template, tags = nil) ⇒ Object 



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# File 'lib/autostacker24/template_preprocessor.rb', line 17

def self.preprocess_tags(template, tags = nil)

  supportedTypes = [
    'AWS::AutoScaling::AutoScalingGroup',
    'AWS::CloudTrail::Trail',
    'AWS::EC2::CustomerGateway',
    'AWS::EC2::DHCPOptions',
    'AWS::EC2::Instance',
    'AWS::EC2::InternetGateway',
    'AWS::EC2::NetworkAcl',
    'AWS::EC2::NetworkInterface',
    'AWS::EC2::RouteTable',
    'AWS::EC2::SecurityGroup',
    'AWS::EC2::Subnet',
    'AWS::EC2::Volume',
    'AWS::EC2::VPC',
    'AWS::EC2::VPCPeeringConnection',
    'AWS::EC2::VPNConnection',
    'AWS::EC2::VPNGateway',
    'AWS::ElasticBeanstalk::Environment',
    'AWS::ElasticLoadBalancing::LoadBalancer',
    'AWS::RDS::DBCluster',
    'AWS::RDS::DBClusterParameterGroup',
    'AWS::RDS::DBInstance',
    'AWS::RDS::DBParameterGroup',
    'AWS::RDS::DBSecurityGroup',
    'AWS::RDS::DBSubnetGroup',
    'AWS::RDS::OptionGroup',
    'AWS::S3::Bucket'
  ]

  unless tags.nil?

    tags_for_asg = adjust_tags_for_asg(tags)

    template["Resources"].each {|(key, value)|

      tags_to_apply = tags
      if value["Type"] == 'AWS::AutoScaling::AutoScalingGroup'
        tags_to_apply = tags_for_asg
      end

      if supportedTypes.include? value["Type"]
        if value["Properties"]["Tags"].nil?
          value["Properties"]["Tags"] = tags_to_apply
        else
          value["Properties"]["Tags"] = (tags_to_apply + value["Properties"]["Tags"]).uniq { |s| s.first }
        end
      end
    }
  end

  template
end

.tokenize(s) ⇒ Object 



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# File 'lib/autostacker24/template_preprocessor.rb', line 120

def self.tokenize(s)
  pattern = /@@|@((\w+(::)?\w+)+)/
  tokens = []
  loop do
    m = pattern.match(s)
    if m
      tokens << m.pre_match unless m.pre_match.empty?
      tokens << m.to_s
      s = m.post_match
    else
      tokens << s unless s.empty? && !tokens.empty?
      break
    end
  end
  tokens
end