Class: Jets::Controller::Middleware::Local

Inherits:
Object
  • Object
show all
Extended by:
Memoist
Defined in:
lib/jets/controller/middleware/local/api_gateway.rb,
lib/jets/controller/middleware/local.rb,
lib/jets/controller/middleware/local/route_matcher.rb,
lib/jets/controller/middleware/local/mimic_aws_call.rb

Overview

Takes a Rack env and converts to ApiGateway event

Defined Under Namespace

Classes: ApiGateway, MimicAwsCall, RouteMatcher

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ Local

Returns a new instance of Local.



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# File 'lib/jets/controller/middleware/local.rb', line 8

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/jets/controller/middleware/local.rb', line 12

def call(env)
  route = RouteMatcher.new(env).find_route
  unless route
    return [404, {'Content-Type' => 'text/html'}, not_found(env)]
  end

  mimic = MimicAwsCall.new(route, env)
  # Make @controller and @meth instance available so we dont not have to pass it around.
  @controller, @meth, @event = mimic.controller, mimic.meth, mimic.event

  if route.to == 'jets/rack#process' # megamode
    # Bypass the Jets middlewares since it could interfere with the Rack
    # application's middleware stack.
    #
    # Rails sends back a transfer-encoding=chunked. Curling Rails directly works,
    # but passing the Rails response back through this middleware results in errors.
    # Disable chunking responses by deleting the transfer-encoding response header.
    # Would like to understand why this happens this better, if someone can explain please let me know.
    status, headers, body = @controller.dispatch! # jets/rack_controller
    headers.delete "transfer-encoding"
    [status, headers, body]
  elsif route.to == 'jets/mount#call' # mount route
    status, headers, body = @controller.dispatch! # jets/mount_controller
    [status, headers, body]
  elsif polymorphic_function?
    run_polymophic_function
  else # Normal Jets request
    mimic_aws_lambda!(env, mimic.vars) unless on_aws?(env)
    @app.call(env)
  end
end

#mimic_aws_lambda!(env, vars) ⇒ Object

Modifies env the in the same way real call from AWS lambda would modify env



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# File 'lib/jets/controller/middleware/local.rb', line 66

def mimic_aws_lambda!(env, vars)
  env.merge!(vars)
  env
end

#not_found(env) ⇒ Object 



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# File 'lib/jets/controller/middleware/local.rb', line 86

def not_found(env)
  message = routes_error_message(env)
  body = <<~HTML
    <!DOCTYPE html>
    <html>
        <head>
            <meta charset="utf-8">
            <title>Route not found</title>
        </head>
        <body>
          #{message}
        </body>
    </html>
  HTML
  StringIO.new(body)
end

#on_aws?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/jets/controller/middleware/local.rb', line 71

def on_aws?(env)
  return false if Jets.env.test? # usually with test we're passing in full API Gateway fixtures with the HTTP_X_AMZN_TRACE_ID
  on_cloud9 = !!(env['HTTP_HOST'] =~ /cloud9\..*\.amazonaws\.com/)
  !!env['HTTP_X_AMZN_TRACE_ID'] && !on_cloud9
end

#polymorphic_function ⇒ Object 



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# File 'lib/jets/controller/middleware/local.rb', line 50

def polymorphic_function
  # Abusing PolyFun to run polymorphic code, should call LambdaExecutor directly
  # after reworking LambdaExecutor so it has a better interface.
  Jets::PolyFun.new(@controller.class, @meth)
end

#polymorphic_function? ⇒ Boolean

Never hit when calling polymorphic function on AWS Lambda. Can only get called with the local server.

Returns:

  • (Boolean) 


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# File 'lib/jets/controller/middleware/local.rb', line 45

def polymorphic_function?
  return false if ENV['_HANDLER'] # slight speed improvement on Lambda
  polymorphic_function.task.lang != :ruby
end

#routes_error_message(env) ⇒ Object 



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# File 'lib/jets/controller/middleware/local.rb', line 77

def routes_error_message(env)
  message = "<h2>404 Error: Route #{env['PATH_INFO'].sub('/','')} not found</h2>"
  if Jets.env != "production"
    message << "<p>Here are the routes defined in your application:</p>"
    message << "#{routes_table}"
  end
  message
end

#routes_table ⇒ Object

Show pretty route table for user to help with debugging in non-production mode



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# File 'lib/jets/controller/middleware/local.rb', line 104

def routes_table
  routes = Jets::Router.routes

  return "Your routes table is empty." if routes.empty?

  text = "Verb | Path | Controller#action\n"
  text << "--- | --- | ---\n"
  routes.each do |route|
    text << "#{route.method} | #{route.path} | #{route.to}\n"
  end
  html = Kramdown::Document.new(text).to_html
  puts html
  html
end

#run_polymophic_function ⇒ Object 



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# File 'lib/jets/controller/middleware/local.rb', line 57

def run_polymophic_function
  resp = polymorphic_function.run(@event, @meth) # polymorphic code
  status = resp['statusCode']
  headers = resp['headers']
  body = StringIO.new(resp['body'])
  [status, headers, body] # triplet
end