require 'cgi' require 'stringio' class Jets::Server # This doesnt really need to be middleware class LambdaAwsProxy def initialize(route, env) @route = route @env = env puts "Rack env:".colorize(:yellow) @env.each do |k,v| puts "#{k}: #{v}" end end def response event = build_event context = {} controller_class = find_controller_class controller_action = find_controller_action fun = Jets::PolyFun.new(controller_class, controller_action) resp = fun.run(event, context) # check the logs for polymorphic function errors # Map lambda proxy response format to rack format status = resp["statusCode"] headers = resp["headers"] || {} headers = {'Content-Type' => 'text/html'}.merge(headers) body = resp["body"] [status, headers, [body]] end def build_event resource = @route.path(:api_gateway) # posts/{id}/edit path = @env['PATH_INFO'].sub('/','') # remove beginning slash { "resource" => "/#{resource}", # "/posts/{id}/edit" "path" => @env['PATH_INFO'], # /posts/tung/edit "httpMethod" => @env['REQUEST_METHOD'], # GET "headers" => request_headers, "queryStringParameters" => query_string_parameters, "pathParameters" => @route.extract_parameters(path), "stageVariables" => nil, "requestContext" => {}, "body" => get_body, "isBase64Encoded" => false, } end # Annoying. The headers part of the AWS Lambda proxy structure # does not consisently use the same casing scheme for the header keys. # Sometimes it looks like this: # Accept-Encoding # and sometimes it looks like this: # cache-control # Map for special cases when the casing doesn't match. CASING_MAP = { "Cache-Control" => "cache-control", "Content-Type" => "content-type", "Origin" => "origin", "Upgrade-Insecure-Requests" => "upgrade-insecure-requests", } # Map rack env headers to Api Gateway event headers. Most rack env headers are # prepended by HTTP_. # # Some API Gateway Lambda Proxy are also in the rack env headers. Example: # # "X-Amz-Cf-Id": "W8DF6J-lx1bkV00eCiBwIq5dldTSGGiG4BinJlxvN_4o8fCZtbsVjw==", # "X-Amzn-Trace-Id": "Root=1-5a0dc1ac-58a7db712a57d6aa4186c2ac", # "X-Forwarded-For": "88.88.88.88, 54.239.203.117", # "X-Forwarded-Port": "443", # "X-Forwarded-Proto": "https", # # For sample dump of the event headers, check out: # spec/fixtures/samples/event-headers-form-post.json # # We generally do add those API Gateway Lambda specific headers because # they would be fake anyway and by not adding them we can distinguish a # local request from a remote request on API Gateway. def request_headers headers = @env.select { |k,v| k =~ /^HTTP_/ }.inject({}) do |h,(k,v)| # map things like HTTP_USER_AGENT to "User-Agent" key = k.sub('HTTP_','').split('_').map(&:capitalize).join('-') h[key] = v h end # Content type is not prepended with HTTP_ but is part of Lambda's event headers thankfully headers["Content-Type"] = @env["CONTENT_TYPE"] if @env["CONTENT_TYPE"] # Adjust the casing so it matches the Lambda AWS Proxy's structure CASING_MAP.each do |nice_casing, bad_casing| if headers.key?(nice_casing) headers[bad_casing] = headers.delete(nice_casing) end end # Way to fake X-Amzn-Trace-Id which on_aws? helper checks. # This is how we distinguish a request from API gateway vs local. if ENV['JETS_ON_AWS'] headers["X-Amzn-Trace-Id"] = "Root=fake-trace-id" end headers end def query_string_parameters Rack::Utils.parse_nested_query(@env['QUERY_STRING']) end # To get the post body: # rack.input: # def get_body # @env["rack.input"] is always provided by rack and we should make # the test data always have rack.input to mimic rack, but but handling # it this way because it's simpler. input = @env["rack.input"] || StringIO.new body = input.read # return nil for blank string, because thats what Lambda AWS_PROXY does body unless body.empty? end def find_controller_class # posts#edit => PostsController @route.controller_name.constantize end def find_controller_action @route.action_name end end end