Fail E2E tests early if template not found via API

qa/qa/runtime/api/request.rb

@@ -12,6 +12,10 @@ module QA
           @session_address = Runtime::Address.new(api_client.address, request_path)
         end
 
+        def mask_url
+          @session_address.address.sub(/private_token=.*/, "private_token=[****]")
+        end
+
         def url
           @session_address.address
         end

qa/qa/runtime/fixtures.rb

@@ -3,10 +3,19 @@
 module QA
   module Runtime
     module Fixtures
+      include Support::Api
+
+      TemplateNotFoundError = Class.new(RuntimeError)
+
       def fetch_template_from_api(api_path, key)
         request = Runtime::API::Request.new(api_client, "/templates/#{api_path}/#{key}")
-        get request.url
-        json_body[:content]
+        response = get(request.url)
+
+        unless response.code == HTTP_STATUS_OK
+          raise TemplateNotFoundError, "Template at #{request.mask_url} could not be found (#{response.code}): `#{response}`."
+        end
+
+        parse_body(response)[:content]
       end
 
       private