use an existing logger for screencap

closes FOO-1440
flag=none

TEST PLAN:
  1) make cutycapt fail with non-200 response
  2) log entry gets written

Change-Id: Ib9b40536e5a6fa597a3f0a305c2254b4612db2e1
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/256274
Reviewed-by: Jacob Burroughs <jburroughs@instructure.com>
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
QA-Review: Ethan Vizitei <evizitei@instructure.com>
Product-Review: Ethan Vizitei <evizitei@instructure.com>

lib/services/screencap_service.rb

@@ -23,7 +23,7 @@ module Services
     def initialize(config)
       @config = config.with_indifferent_access
     end
-        
+
     def snapshot_url_to_file(url, tmpfile)
       url_params = { url: url }.to_query
       full_url = "#{@config[:url]}?#{url_params}"
@@ -32,10 +32,9 @@ module Services
           http_response.read_body do |chunk|
             tmpfile.write chunk
           end
-  
           tmpfile.close
         else
-          logger.error("Snapshot failed with error code #{http_response.code}")
+          Rails.logger.error("Snapshot failed with error code #{http_response.code}")
           return false
         end
       end

spec/lib/services/screencap_service_spec.rb

@@ -39,9 +39,9 @@ module Services
         token: 'AN_API_TOKEN'
       }
     end
-    
+
     subject { described_class.new(config) }
-    
+
     context ".snapshot_url_to_file" do
       it 'calls the provided url' do
         @stub = stub_request(:get, config[:url]).
@@ -49,7 +49,20 @@ module Services
           to_return(status: 200, body: "IMAGE_GOES_HERE")
 
         Tempfile.create('example.png') do |f|
-          subject.snapshot_url_to_file("https://www.example.com", f)
+          result = subject.snapshot_url_to_file("https://www.example.com", f)
+          expect(result).to be_truthy
+        end
+        expect(@stub).to have_been_requested.times(1)
+      end
+
+      it 'returns false if it gets a non-200' do
+        @stub = stub_request(:get, config[:url]).
+          with(query: { url: 'https://www.example.com' }).
+          to_return(status: 500, body: "IMAGE_GOES_HERE")
+
+        Tempfile.create('example.png') do |f|
+          result = subject.snapshot_url_to_file("https://www.example.com", f)
+          expect(result).to be_falsey
         end
         expect(@stub).to have_been_requested.times(1)
       end