[api] do not read the post body unless we have to for validate

This reduces memory usage for chromium commits - at least I hope so

src/api/app/controllers/application_controller.rb

@@ -637,12 +637,21 @@ def self.validate_action(opt)
     end
   end
 
+  class LazyRequestReader
+    def initialize(req)
+      @req = req
+    end
+    def to_s
+      @req.raw_post
+    end
+  end
+
   def validate_xml_request(method = nil)
     opt = params()
     opt[:method] = method || request.method.to_s
     opt[:type] = 'request'
     logger.debug "Validate XML request: #{request}"
-    Suse::Validator.validate(opt, request.raw_post.to_s)
+    Suse::Validator.validate(opt, LazyRequestReader.new(request))
   end
 
   def validate_xml_response

src/api/app/controllers/source_controller.rb

@@ -20,7 +20,6 @@ class IllegalRequest < APIException
   validate_action update_project_meta: { request: :project, response: :status}
   validate_action update_package_meta: { request: :package, response: :status}
 
-  skip_before_action :validate_xml_request, :only => [:file]
   skip_before_action :extract_user, only: [:lastevents_public]
 
   before_action :require_valid_project_name, except: [:index, :lastevents, :lastevents_public, :global_command]

src/api/lib/opensuse/validator.rb

@@ -93,6 +93,7 @@ def validate(opt, content)
         if content.nil?
           raise "illegal option; need content for #{schema_base_filename}"
         end
+        content = content.to_s
         if content.empty?
           logger.debug "no content, skipping validation for #{schema_file}"
           raise ValidationError, "Document is empty, not allowed for #{schema_base_filename}"