Class: Jets::Controller::Handler::Apigw

Inherits:
Object
  • Object
show all
Extended by:
Memoist
Defined in:
lib/jets/controller/handler/apigw.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(event, context, controller, meth, rack_env) ⇒ Apigw

Returns a new instance of Apigw.



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# File 'lib/jets/controller/handler/apigw.rb', line 10

def initialize(event, context, controller, meth, rack_env)
  @event = event
  @context = context
  @controller = controller
  @meth = meth
  @rack_env = rack_env
end

Instance Attribute Details

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/jets/controller/handler/apigw.rb', line 9

def context
  @context
end

#controller ⇒ Object (readonly)

Returns the value of attribute controller.



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# File 'lib/jets/controller/handler/apigw.rb', line 9

def controller
  @controller
end

#event ⇒ Object (readonly)

Returns the value of attribute event.



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# File 'lib/jets/controller/handler/apigw.rb', line 9

def event
  @event
end

#meth ⇒ Object (readonly)

Returns the value of attribute meth.



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# File 'lib/jets/controller/handler/apigw.rb', line 9

def meth
  @meth
end

#rack_env ⇒ Object (readonly)

Returns the value of attribute rack_env.



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# File 'lib/jets/controller/handler/apigw.rb', line 9

def rack_env
  @rack_env
end

Instance Method Details

#add_response_headers(resp, headers) ⇒ Object 



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# File 'lib/jets/controller/handler/apigw.rb', line 64

def add_response_headers(resp, headers)
  resp['headers'] = headers.reject { |_, val| val.is_a?(Array) }
  multi_value_headers = headers.select { |_, val| val.is_a?(Array) }

  resp['multiValueHeaders'] = multi_value_headers unless multi_value_headers.blank?
end

#adjust_for_elb(resp) ⇒ Object

Note: ELB is not officially support. This is just in case users wish to manually connect ELBs to the functions created by Jets.



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# File 'lib/jets/controller/handler/apigw.rb', line 73

def adjust_for_elb(resp)
  return resp unless from_elb?

  # ELB requires statusCode to be an Integer whereas API Gateway requires statusCode to be a String
  status = resp["statusCode"] = resp["statusCode"].to_i

  # ELB also requires statusDescription attribute
  status_desc = Rack::Utils::HTTP_STATUS_CODES[status]
  status_desc = status_desc.nil? ? status.to_s : "#{status} #{status_desc}"
  resp["statusDescription"] = status_desc

  resp
end

#convert_to_api_gateway(status, headers, body) ⇒ Object

Transform the structure to AWS_PROXY compatible structure docs.aws.amazon.com/apigateway/latest/developerguide/set-up-lambda-proxy-integrations.html#api-gateway-simple-proxy-for-lambda-output-format



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# File 'lib/jets/controller/handler/apigw.rb', line 50

def convert_to_api_gateway(status, headers, body)
  base64 = headers["x-jets-base64"] == 'yes'
  body = body.respond_to?(:read) ? body.read : body
  body = Base64.encode64(body) if base64

  {}.tap do |resp|
    resp['statusCode'] = status
    resp['body'] = body
    resp['isBase64Encoded'] = base64
    add_response_headers(resp, headers)
    adjust_for_elb(resp)
  end
end

#from_elb? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jets/controller/handler/apigw.rb', line 87

def from_elb?
  # NOTE: @event["requestContext"]["elb"] is set when the request is coming from an elb
  # Can set JETS_ELB=1 for local testing
  @event["requestContext"] && @event["requestContext"]["elb"] || ENV['JETS_ELB']
end

#process_through_middlewares ⇒ Object

  1. Convert API Gateway event event to Rack env

  2. Process using full Rack middleware stack

  3. Convert back to API gateway response structure payload

Returns back API Gateway response hash structure Only called when running in AWS Lambda.

Set the jets.* env variables so we have access to them in the middleware. The controller instance is called in the Main middleware. On AWS, will use original event and context. On local server, will use Middleware::Mimic event and context.



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# File 'lib/jets/controller/handler/apigw.rb', line 29

def process_through_middlewares
  env = rack_env.merge(
    'jets.controller' => @controller, # original controller instance from handler
    'jets.context'    => @context,    # original AWS Lambda context
    'jets.event'      => @event,      # original AWS Lambda event
    'jets.meth'       => @meth,
  )
  status, headers, body = Jets.application.call(env) # goes through full middleware stack
  # middleware can handle Array or BodyProxy, APIGW require Strings
  case body
  when Rack::Files::Iterator
    str = File.read(body.path)
  else
    # join for Rack::BodyProxy or Array
    str = body.join
  end
  convert_to_api_gateway(status, headers, str)
end