Class: Lono::Template::DSL

Inherits:
Object
  • Object
show all
Defined in:
lib/lono/template/dsl.rb

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ DSL

Returns a new instance of DSL.



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# File 'lib/lono/template/dsl.rb', line 2

def initialize(options={})
  @options = options
  @config_path = "#{Lono.root}/config"
  Lono::ProjectChecker.check
  @templates = []
  @results = {}
  @detected_format = nil
end

Instance Method Details

#build_templates ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 82

def build_templates
  options = @options.merge(detected_format: @detected_format)
  @templates.each do |t|
    @results[t[:name]] = Lono::Template::Template.new(t[:name], t[:block], options).build
  end
end

#detect_format ⇒ Object

Detects the format of the templates. Checks the extension of all the templates files. All the templates must be of the same format, either all json or all yaml.



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# File 'lib/lono/template/dsl.rb', line 71

def detect_format
  extensions = Dir.glob("#{Lono.root}/templates/**/*").map do |path|
    File.extname(path).sub(/^\./,'')
  end.reject(&:empty?).uniq
  extensions.include?('yml') ? 'yml' : 'json' # defaults to yml - falls back to json
end

#ensure_parent_dir(path) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 154

def ensure_parent_dir(path)
  dir = File.dirname(path)
  FileUtils.mkdir_p(dir) unless File.exist?(dir)
end

#evaluate_folder(folder) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 27

def evaluate_folder(folder)
  paths = Dir.glob("#{@config_path}/templates/#{folder}/**/*")
  paths.select{ |e| File.file?(e) }.each do |path|
    evaluate_template(path)
  end
end

#evaluate_template(path) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 34

def evaluate_template(path)
  begin
    instance_eval(File.read(path), path)
  rescue Exception => e
    template_evaluation_error(e)
    puts "\nFull error:"
    raise
  end
end

#evaluate_templates ⇒ Object

Instance eval’s all the files within each folder under

config/lono/base and config/lono/[Lono.env]

Base gets base first and then the Lono.env configs get evaluate second. This means the env specific configs override the base configs.



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# File 'lib/lono/template/dsl.rb', line 21

def evaluate_templates
  evaluate_folder("base")
  evaluate_folder(Lono.env)
  @detected_format = detect_format
end

#output_format(text) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 136

def output_format(text)
  @options[:pretty] ? prettify(text) : text
end

#prettify(text) ⇒ Object

Input text is either yaml or json. Do not prettify yaml format because it removes the !Ref like CloudFormation notation



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# File 'lib/lono/template/dsl.rb', line 142

def prettify(text)
  @detected_format == "json" ? JSON.pretty_generate(JSON.parse(text)) : yaml_format(text)
end

#run(options = {}) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 11

def run(options={})
  evaluate_templates
  build_templates
  write_output
end

#template(name, &block) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 78

def template(name, &block)
  @templates << {name: name, block: block}
end

#template_evaluation_error(e) ⇒ Object

Prints out a user friendly task_definition error message



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# File 'lib/lono/template/dsl.rb', line 45

def template_evaluation_error(e)
  error_info = e.backtrace.first
  path, line_no, _ = error_info.split(':')
  line_no = line_no.to_i
  puts "Error evaluating #{path}:".colorize(:red)
  puts e.message
  puts "Here's the line in #{path} with the error:\n\n"

  contents = IO.read(path)
  content_lines = contents.split("\n")
  context = 5 # lines of context
  top, bottom = [line_no-context-1, 0].max, line_no+context-1
  spacing = content_lines.size.to_s.size
  content_lines[top..bottom].each_with_index do |line_content, index|
    line_number = top+index+1
    if line_number == line_no
      printf("%#{spacing}d %s\n".colorize(:red), line_number, line_content)
    else
      printf("%#{spacing}d %s\n", line_number, line_content)
    end
  end
end

#validate(text, path) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 106

def validate(text, path)
  if @detected_format == "json"
    validate_json(text, path)
  else
    validate_yaml(text, path)
  end
end

#validate_json(json, path) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 125

def validate_json(json, path)
  begin
    JSON.parse(json)
  rescue JSON::ParserError => e
    puts "Invalid json.  Output written to #{path} for debugging".colorize(:red)
    puts "ERROR: #{e.message}".colorize(:red)
    File.open(path, 'w') {|f| f.write(json) }
    exit 1
  end
end

#validate_yaml(yaml, path) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 114

def validate_yaml(yaml, path)
  begin
    YAML.load(yaml)
  rescue Psych::SyntaxError => e
    puts "Invalid yaml.  Output written to #{path} for debugging".colorize(:red)
    puts "ERROR: #{e.message}".colorize(:red)
    File.open(path, 'w') {|f| f.write(yaml) }
    exit 1
  end
end

#write_output ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 89

def write_output
  output_path = "#{Lono.root}/output"
  FileUtils.rm_rf(output_path) if @options[:clean]
  FileUtils.mkdir(output_path) unless File.exist?(output_path)
  puts "Generating CloudFormation templates:" unless @options[:quiet]
  @results.each do |name,text|
    path = "#{output_path}/#{name}".sub(/^\.\//,'') # strip leading '.'
    path += ".#{@detected_format}"
    puts "  #{path}" unless @options[:quiet]
    ensure_parent_dir(path)
    validate(text, path)
    File.open(path, 'w') do |f|
      f.write(output_format(text))
    end
  end
end

#yaml_format(text) ⇒ Object 



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# File 'lib/lono/template/dsl.rb', line 146

def yaml_format(text)
  comment =<<~EOS
    # This file was generated with lono. Do not edit directly, the changes will be lost.
    # More info: http://lono.cloud
  EOS
  "#{comment}#{text}"
end