Class: Jets::Controller::Rack::Adapter

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

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(event, context) ⇒ Adapter

Returns a new instance of Adapter.



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# File 'lib/jets/controller/rack/adapter.rb', line 13

def initialize(event, context)
  @event, @context = event, context
end

Class Method Details

.process(event, context) ⇒ Object

Returns back API Gateway response hash structure



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# File 'lib/jets/controller/rack/adapter.rb', line 8

def self.process(event, context)
  adapter = new(event, context)
  adapter.process
end

Instance Method Details

#add_response_headers(resp, headers) ⇒ Object 



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# File 'lib/jets/controller/rack/adapter.rb', line 46

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/rack/adapter.rb', line 55

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/rack/adapter.rb', line 32

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

#env ⇒ Object 



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# File 'lib/jets/controller/rack/adapter.rb', line 25

def env
  Env.new(@event, @context, adapter: true).convert # convert to Rack env
end

#from_elb? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jets/controller/rack/adapter.rb', line 69

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 ⇒ 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



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# File 'lib/jets/controller/rack/adapter.rb', line 20

def process
  status, headers, body = Jets.application.call(env)
  convert_to_api_gateway(status, headers, body)
end

#rack_vars(vars) ⇒ Object

Called from Jets::Controller::Base.process. Example:

adapter.rack_vars(
  'jets.controller' => self,
  'lambda.context' => context,
  'lambda.event' => event,
  'lambda.meth' => meth,
)

Passes a these special variables so we have access to them in the middleware. The controller instance is called in the Main middleware. The lambda.* info is used by the Rack::Local middleware to create a mimiced controller for the local server.



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# File 'lib/jets/controller/rack/adapter.rb', line 89

def rack_vars(vars)
  env.merge!(vars)
end