Class: Yutani::Mod

Inherits:
DSLEntity show all
Defined in:
lib/yutani/mod.rb

Overview

Maps to a terraform module. Named ‘mod’ to avoid confusion with ruby ‘module’. It can contain :

  • other modules

  • resources

  • other resources (provider, data, etc)

  • variables

  • outputs

Its block is evaluated depending upon whether it is enclosed within another module It has the following properties

  • mandatory name of type symbol

  • optional scope of type hash

  • ability to output a tar of its contents

Direct Known Subclasses

Stack

Defined Under Namespace

Classes: InvalidReferencePathException, MyHash

Instance Attribute Summary collapse

Attributes inherited from DSLEntity

#scope

Instance Method Summary collapse

Methods inherited from DSLEntity

#hiera

Constructor Details

#initialize(name, parent, local_scope, parent_scope, &block) ⇒ Mod

Returns a new instance of Mod.



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# File 'lib/yutani/mod.rb', line 23

def initialize(name, parent, local_scope, parent_scope, &block)
  @name                = name.to_sym

  @scope               = parent_scope.merge(local_scope)
  @scope[:module_name] = name
  @local_scope         = local_scope
  @parent              = parent

  @mods                = []
  @resources           = []
  @providers           = []
  @outputs             = {}
  @params              = {}
  @variables           = {}

  instance_eval        &block
end

Instance Attribute Details

#block ⇒ Object

Returns the value of attribute block.



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# File 'lib/yutani/mod.rb', line 21

def block
  @block
end

#mods ⇒ Object

Returns the value of attribute mods.



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# File 'lib/yutani/mod.rb', line 21

def mods
  @mods
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/yutani/mod.rb', line 21

def name
  @name
end

#outputs ⇒ Object

Returns the value of attribute outputs.



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# File 'lib/yutani/mod.rb', line 21

def outputs
  @outputs
end

#params ⇒ Object

Returns the value of attribute params.



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# File 'lib/yutani/mod.rb', line 21

def params
  @params
end

#providers ⇒ Object

Returns the value of attribute providers.



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# File 'lib/yutani/mod.rb', line 21

def providers
  @providers
end

#resources ⇒ Object

Returns the value of attribute resources.



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# File 'lib/yutani/mod.rb', line 21

def resources
  @resources
end

#variables ⇒ Object

Returns the value of attribute variables.



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# File 'lib/yutani/mod.rb', line 21

def variables
  @variables
end

Instance Method Details

#child?(mod) ⇒ Boolean

given name of mod, return bool

Returns:

  • (Boolean) 


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# File 'lib/yutani/mod.rb', line 138

def child?(mod)
  children.map{|m| m.name }.include? mod.name
end

#child_by_name(name) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 142

def child_by_name(name)
  children.find{|child| child.name == name.to_sym}
end

#children ⇒ Object 



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# File 'lib/yutani/mod.rb', line 125

def children
  @mods
end

#create_dir_tree(prefix) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 300

def create_dir_tree(prefix)
  dir_tree(DirectoryTree.new(prefix), '')
end

#debug ⇒ Object 



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# File 'lib/yutani/mod.rb', line 61

def debug
  resolve_references!(self)
  #pp @mods.unshift(self).map{|m| m.to_h }
end

#descendents ⇒ Object 



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# File 'lib/yutani/mod.rb', line 129

def descendents
  children + children.map{|c| c.descendents}.flatten
end

#dir_path ⇒ Object 



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# File 'lib/yutani/mod.rb', line 105

def dir_path
  tf_name
end

#dir_tree(dt, prefix) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 304

def dir_tree(dt, prefix)
  full_dir_path = File.join(prefix, self.dir_path)
  main_tf_path = File.join(full_dir_path, 'main.tf.json')

  dt.add_file(
    main_tf_path,
    0644,
    self.pretty_json
  )

  mods.each do |m|
    m.dir_tree(dt, full_dir_path)
  end

  dt
end

#generate_pathway(mods, path) ⇒ Object

rel_path: relative path to a target mod ret an array of mods tracing that path sorted from target -> source mods: array of module objects, which after being built is returned path: array of path strings: i.e. [.. .. .. a b c]



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# File 'lib/yutani/mod.rb', line 158

def generate_pathway(mods, path)
  curr = path.shift

  case curr
  when /[a-z]+/
    child = child_by_name(curr)
    if child.nil?
      raise InvalidReferencePathException, "no such module #{curr}" 
    else
      child.generate_pathway(mods.unshift(self), path)
    end
  when '..'
    if @parent.nil?
      raise InvalidReferencePathException, "no such module #{curr}" 
    else
      @parent.generate_pathway(mods.unshift(self), path)
    end
  when nil
    return mods.unshift(self)
  else
    raise InvalidReferencePathException, "invalid path component: #{curr}" 
  end
end

#mod(name, **scope, &block) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 41

def mod(name, **scope, &block)

  @mods << Mod.new(name, self, scope, @scope, &block)
end

#parent?(mod) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/yutani/mod.rb', line 133

def parent?(mod)
  @parent.name == mod.name
end

#path ⇒ Object 



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# File 'lib/yutani/mod.rb', line 146

def path
  File.join(@parent.path, name.to_s)
end

#pretty_json ⇒ Object 



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# File 'lib/yutani/mod.rb', line 121

def pretty_json
  JSON.pretty_generate(to_h)
end

#propagate(prev, nxt, var) ⇒ Object

recursive linked-list function, propagating a variable from a target module to a source module seed var with array of [type,name,attr]



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# File 'lib/yutani/mod.rb', line 185

def propagate(prev, nxt, var)
  if prev.empty?
    # we are the source module
    if nxt.empty?
      # src and target in same mod
      "${%s}" % var.join('.')
    else
      if self.child? nxt.first
        # there is no 'composition' mod,
        new_var = [self.name, var].flatten
        nxt.first.params[new_var.join('_')] = "${%s}" % new_var.join('.')
        nxt.first.variables[new_var] = ''

        nxt.shift.propagate(prev.push(self), nxt, var)
      elsif self.parent?(nxt.first)
        # we are propagating upward the variable
        self.outputs[var.join('_')] = "${%s}" % var.join('.')
        nxt.shift.propagate(prev.push(self), nxt, var.join('_'))
      else
        raise "Propagation error!"
      end
    end
  else
    if nxt.empty?
      # we're the source module
      if self.child? prev.last
        # it's been propagated 'up' to us
        "${module.%s.%s}" % [prev.last.name, var]
      elsif self.parent? prev.last
        # it's been propagated 'down' to us
        "${var.%s}" % var
      else
        raise "Propagation error!"
      end
    else
      if self.child? prev.last and self.child? nxt.first
        # we're a 'composition' module; the common ancestor
        # to source and target modules
        new_var = [prev.last.name, var]
        nxt.first.params[new_var.join('_')] = "${module.%s.%s}" % new_var
        nxt.first.variables[new_var.join('_')] = ""

        nxt.shift.propagate(prev.push(self), nxt, new_var.join('_'))
      elsif self.child? prev.last and self.parent? nxt.first
        # we're propagating 'upward' the variable
        # towards the common ancestor
        
        new_var = [prev.last.name, var]
        self.outputs[new_var.join('_')] = "${module.%s.%s}" % new_var

        nxt.shift.propagate(prev.push(self), nxt, new_var.join('_'))
      elsif self.parent? prev.last and self.parent? nxt.first
        # we cannot be a child to two parents in a tree!
        raise "Progation error!"
      elsif self.parent? prev.last and self.child? nxt.first
        nxt.first.params[var] = "${var.%s}" % var
        nxt.first.variables[var] = ""

        nxt.shift.propagate(prev.push(self), nxt, var)
      else
        raise "Propagation error!"
      end
    end
  end
end

#provider(provider_name, **scope, &block) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 115

def provider(provider_name, **scope, &block)
  merged_scope = @scope.merge(scope)
  @providers <<
    Provider.new(provider_name, merged_scope, &block)
end

#resolve_references! ⇒ Object 



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# File 'lib/yutani/mod.rb', line 251

def resolve_references!
  @resources.each do |r|
    r.resolve_references! do |ref|

      matching_resources = []

      path_components = ref.relative_path(self).split('/')
      mod_path = generate_pathway([], path_components)
      target_mod = mod_path.shift
 
      # lookup matching resources in mod_path.first
      matches = ref.find_matching_resources_in_module!(target_mod)

      if matches.empty?
        raise ReferenceException, 
          "no matching resources found in mod #{target_mod.name}"
      end

      interpolation_strings = matches.map do |res|
        ra = ResourceAttribute.new(res.resource_type, res.resource_name, ref.attr)
        # clone mod_path, because propagate() will alter it
        target_mod.propagate([], mod_path.clone, [ra.type, ra.name, ra.attr])
      end
      interpolation_strings.length == 1 ? interpolation_strings[0] : 
        interpolation_strings
    end
  end

  children.each do |m|
    m.resolve_references!
  end
end

#resource(resource_type, identifiers, **scope, &block) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 109

def resource(resource_type, identifiers, **scope, &block)
  merged_scope = @scope.merge(scope)
  @resources <<
    Resource.new(resource_type, identifiers, merged_scope, &block)
end

#resources_hash ⇒ Object 



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# File 'lib/yutani/mod.rb', line 53

def resources_hash
  @resources.inject({}) do |r_hash, r|
    r_hash[r.resource_type] ||= {}
    r_hash[r.resource_type][r.resource_name] = r 
    r_hash
  end
end

#source(path) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 46

def source(path)
  absolute_path = File.expand_path(path, File.dirname(Yutani.entry_path))
  contents = File.read absolute_path

  instance_eval contents, path
end

#tar(filename) ⇒ Object 



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# File 'lib/yutani/mod.rb', line 284

def tar(filename)
  # ideally, this needs to be done automatically as part of to_h
  resolve_references!

  File.open(filename, 'w+') do |tarball|
    create_dir_tree('./').to_tar(tarball)
  end
end

#tf_name ⇒ Object 



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# File 'lib/yutani/mod.rb', line 99

def tf_name
  dirs = @local_scope.values.map{|v| v.to_s.gsub('-', '_') }
  dirs.unshift(name)
  dirs.join('_')
end

#to_fs(prefix = './terraform') ⇒ Object 



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# File 'lib/yutani/mod.rb', line 293

def to_fs(prefix='./terraform')
  # ideally, this needs to be done automatically as part of to_h
  resolve_references!

  create_dir_tree(prefix).to_fs
end

#to_h ⇒ Object

this generates the contents of *.tf.main



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# File 'lib/yutani/mod.rb', line 71

def to_h
  h = { 
    module: @mods.inject({}) {|modules,m|
      modules[m.tf_name] = {}
      modules[m.tf_name][:source] = m.dir_path
      modules[m.tf_name].merge! m.params
      modules
    },
    resource: @resources.inject(MyHash.new){|resources,r|
      resources.deep_merge(r.to_h)
    },
    provider: @providers.inject(MyHash.new){|providers,r|
      providers.deep_merge(r.to_h)
    },
    output: @outputs.inject({}){|outputs,(k,v)|
      outputs[k] = { value: v }
      outputs
    },
    variable: @variables.inject({}){|variables,(k,v)|
      variables[k] = {}
      variables
    }
  }

  # terraform doesn't like empty output and variable collections
  h.delete_if {|_,v| v.empty? }
end