rename option to skip_on_invalid_json

Fixes #24

Author: klausmeyer

lib/logstash/filters/json.rb

@@ -59,8 +59,8 @@ class LogStash::Filters::Json < LogStash::Filters::Base
   # successful match
   config :tag_on_failure, :validate => :array, :default => ["_jsonparsefailure"]
 
-  # Allow to quietly fall-back to plain-text (aka skip the filter without warnings and tags)
-  config :fallback_mode, :validate => :boolean, :default => false
+  # Allow to skip filter on invalid json (allows to handle json and non-json data without warnings)
+  config :skip_on_invalid_json, :validate => :boolean, :default => false
 
   def register
     # Nothing to do here
@@ -75,7 +75,7 @@ def filter(event)
     begin
       parsed = LogStash::Json.load(source)
     rescue => e
-      unless @fallback_mode
+      unless @skip_on_invalid_json
         @tag_on_failure.each{|tag| event.tag(tag)}
         @logger.warn("Error parsing json", :source => @source, :raw => source, :exception => e)
       end

spec/filters/json_spec.rb

@@ -176,10 +176,10 @@
     end
   end
 
-  describe "parse mixture of json an non-json content (fallback mode)" do
+  describe "parse mixture of json an non-json content (skip_on_invalid_json)" do
     subject(:filter) {  LogStash::Filters::Json.new(config)  }
 
-    let(:config) { {"source" => "message", "remove_field" => ["message"], "fallback_mode" => fallback_mode} }
+    let(:config) { {"source" => "message", "remove_field" => ["message"], "skip_on_invalid_json" => skip_on_invalid_json} }
     let(:event) { LogStash::Event.new("message" => message) }
 
     before(:each) do
@@ -190,8 +190,8 @@
 
     let(:message) { "this is not a json message" }
 
-    context "with fallback_mode off" do
-      let(:fallback_mode) { false }
+    context "with `skip_on_invalid_json` set to false" do
+      let(:skip_on_invalid_json) { false }
 
       it "sends a warning to the logger" do
         expect(filter.logger).to have_received(:warn).with("Error parsing json", anything())
@@ -206,8 +206,8 @@
       end
     end
 
-    context "with fallback_mode on" do
-      let(:fallback_mode) { true }
+    context "with `skip_on_invalid_json` set to true" do
+      let(:skip_on_invalid_json) { true }
 
       it "sends no warning" do
         expect(filter.logger).to_not have_received(:warn)