Module: Stacker

Extended by:
Stacker
Included in:
Stacker
Defined in:
lib/autostacker24/stacker.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#credentials ⇒ Object

Returns the value of attribute credentials.



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

def credentials
  @credentials
end

#region ⇒ Object

Returns the value of attribute region.



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

def region
  @region
end

Instance Method Details

#all_stack_names ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 121

def all_stack_names
  all_stacks.map{|s| s.stack_name}
end

#all_stacks ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 125

def all_stacks
  cloud_formation.describe_stacks.stacks
end

#cloud_formation ⇒ Object

lazy CloudFormation client



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# File 'lib/autostacker24/stacker.rb', line 161

def cloud_formation # lazy CloudFormation client
  unless @lazy_cloud_formation
    params = {}
    params[:credentials] = @credentials if @credentials
    params[:region] = @region if @region
    @lazy_cloud_formation = Aws::CloudFormation::Client.new(params)
  end
  @lazy_cloud_formation
end

#create_or_update_stack(stack_name, template, parameters, parent_stack_name = nil) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 25

def create_or_update_stack(stack_name, template, parameters, parent_stack_name = nil)
  if find_stack(stack_name).nil?
    create_stack(stack_name, template, parameters, parent_stack_name)
  else
    update_stack(stack_name, template, parameters, parent_stack_name)
  end
end

#create_stack(stack_name, template, parameters, parent_stack_name = nil) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 33

def create_stack(stack_name, template, parameters, parent_stack_name = nil)
  merge_and_validate(template, parameters, parent_stack_name)
  cloud_formation.create_stack(stack_name:    stack_name,
                               template_body: template_body(template),
                               on_failure:    'DELETE',
                               parameters:    transform_input(parameters),
                               capabilities:  ['CAPABILITY_IAM'])
  wait_for_stack(stack_name, :create)
end

#delete_stack(stack_name) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 81

def delete_stack(stack_name)
  seen_events = get_stack_events(stack_name).map {|e| e[:event_id]}
  cloud_formation.delete_stack(stack_name: stack_name)
  wait_for_stack(stack_name, :delete, seen_events)
end

#estimate_template_cost(template, parameters) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 129

def estimate_template_cost(template, parameters)
  cloud_formation.estimate_template_cost(:template_body => template_body(template), :parameters => transform_input(parameters))
end

#find_stack(stack_name) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 114

def find_stack(stack_name)
  cloud_formation.describe_stacks(stack_name: stack_name).stacks.first
rescue Aws::CloudFormation::Errors::ValidationError => error
  raise error unless error.message =~ /does not exist/i # may be flaky, do more research in API
  nil
end

#get_stack_events(stack_name_or_id) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 157

def get_stack_events(stack_name_or_id)
  events = cloud_formation.describe_stack_events(stack_name: stack_name_or_id).data.stack_events
end

#get_stack_output(stack_name) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 137

def get_stack_output(stack_name)
  stack = find_stack(stack_name)
  raise "stack #{stack_name} not found" unless stack
  transform_output(stack.outputs).freeze
end

#get_stack_outputs(stack_name) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 133

def get_stack_outputs(stack_name)
  get_stack_output(stack_name)
end

#get_stack_resources(stack_name) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 152

def get_stack_resources(stack_name)
  resources = cloud_formation.describe_stack_resources(stack_name: stack_name).data.stack_resources
  resources.inject({}){|map, resource| map.merge(resource.logical_resource_id.to_sym => resource)}.freeze
end

#template_body(template) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 171

def template_body(template)
  template = File.read(template) if File.exists?(template)
  AutoStacker24::Preprocessor.preprocess(template)
end

#transform_input(input) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 147

def transform_input(input)
  input.each{|k,v| raise "#{k} must not be nil" if v.nil? }
  input.inject([]) { |m, kv| m << {parameter_key: kv[0].to_s, parameter_value: kv[1].to_s} }
end

#transform_output(output) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 143

def transform_output(output)
  output.inject({}) { |m, o| m.merge(o.output_key.to_sym => o.output_value) }
end

#update_stack(stack_name, template, parameters, parent_stack_name = nil) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 43

def update_stack(stack_name, template, parameters, parent_stack_name = nil)
  seen_events = get_stack_events(stack_name).map {|e| e[:event_id]}
  begin
    merge_and_validate(template, parameters, parent_stack_name)
    cloud_formation.update_stack(stack_name:    stack_name,
                                 template_body: template_body(template),
                                 parameters:    transform_input(parameters),
                                 capabilities:  ['CAPABILITY_IAM'])
  rescue Aws::CloudFormation::Errors::ValidationError => error
    raise error unless error.message =~ /No updates are to be performed/i # may be flaky, do more research in API
    find_stack(stack_name)
  else
    wait_for_stack(stack_name, :update, seen_events)
  end
end

#validate_template(template) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 77

def validate_template(template)
  cloud_formation.validate_template(template_body: template_body(template))
end

#wait_for_stack(stack_name, operation, seen_events = Set.new) ⇒ Object 



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# File 'lib/autostacker24/stacker.rb', line 87

def wait_for_stack(stack_name, operation, seen_events = Set.new)
  timeout_in_minutes = 60 # for now
  stop_time   = Time.now + timeout_in_minutes * 60
  finished    = /(CREATE_COMPLETE|UPDATE_COMPLETE|DELETE_COMPLETE|ROLLBACK_COMPLETE|ROLLBACK_FAILED|CREATE_FAILED|DELETE_FAILED)$/
  puts "waiting for #{operation} stack #{stack_name}"
  stack_id = find_stack(stack_name)[:stack_id]

  while Time.now < stop_time
    sleep(5)
    stack = find_stack(stack_name)
    status = stack ? stack.stack_status : 'DELETE_COMPLETE'
    expected_status = case operation
                        when :create then /CREATE_COMPLETE$/
                        when :update then /UPDATE_COMPLETE$/
                        when :delete then /DELETE_COMPLETE$/
                      end
    new_events = get_stack_events(stack_id).select{|e| !seen_events.include?(e[:event_id])}.sort_by{|e| e[:timestamp]}
    new_events.each do |e|
      seen_events << e[:event_id]
      puts "#{e[:timestamp]}\t#{e[:resource_status].ljust(20)}\t#{e[:resource_type].ljust(40)}\t#{e[:logical_resource_id].ljust(30)}\t#{e[:resource_status_reason]}"
    end
    return true if status =~ expected_status
    raise "#{operation} #{stack_name} failed, current status #{status}" if status =~ finished
  end
  raise "waiting for #{operation} stack #{stack_name} timed out after #{timeout_in_minutes} minutes"
end