Merge pull request #242 from tongueroo/adjust-for-elb

adjust resp when request coming from elb
rubyonjets · May 2, 2019 · af4bb74 · af4bb74
2 parents 0c7e628 + 2220db2
commit af4bb74
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Showing 3 changed files with 35 additions and 4 deletions.
diff --git a/lib/jets/controller/rack/adapter.rb b/lib/jets/controller/rack/adapter.rb
@@ -33,12 +33,37 @@ 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
-      {
+
+      resp = {
         "statusCode" => status,
         "headers" => headers,
         "body" => body,
         "isBase64Encoded" => base64,
       }
+      adjust_for_elb(resp)
+      resp
+    end
+
+    # Note: ELB is not officially support. This is just in case users wish to manually
+    # connect ELBs to the functions created by Jets.
+    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
+
+    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
 
     # Called from Jets::Controller::Base.process. Example:

diff --git a/lib/jets/controller/rendering/rack_renderer.rb b/lib/jets/controller/rendering/rack_renderer.rb
@@ -165,7 +165,11 @@ def normalize_status_code(code)
                     else
                       code
                     end
-      (status_code || 200).to_s # API Gateway requires a string but rack is okay with either
+
+      # API Gateway requires status to be String but local rack is okay with either
+      # Note, ELB though requires status to be an Integer. We'll later in rack/adapter.rb
+      # adjust status to an Integer if request is coming from an ELB.
+      (status_code || 200).to_s
     end
 
     def set_content_type!(status, headers)

diff --git a/lib/jets/processors/main_processor.rb b/lib/jets/processors/main_processor.rb
@@ -35,8 +35,10 @@ def run
       Jets.increase_call_count
 
       if result.is_a?(Hash) && result["headers"]
-        result["headers"]["x-jets-call-count"] = Jets.call_count
-        result["headers"]["x-jets-prewarm-count"] = Jets.prewarm_count
+        # API Gateway is okay with the header values as Integers but
+        # ELBs are more strict about this and require the header values to be Strings
+        result["headers"]["x-jets-call-count"] = Jets.call_count.to_s
+        result["headers"]["x-jets-prewarm-count"] = Jets.prewarm_count.to_s
       end
 
       result