fix #346. Fix dump_stats and allow configuration to disable

README.md

@@ -58,6 +58,7 @@ when true (default: `true`)
 * `skip_container_metadata` - Skip some of the container data of the metadata. The metadata will not contain the container_image and container_image_id fields.
 * `skip_master_url` - Skip the master_url field from the metadata.
 * `skip_namespace_metadata` - Skip the namespace_id field from the metadata. The fetch_namespace_metadata function will be skipped. The plugin will be faster and cpu consumption will be less.
+* 'stats_interval` - The interval to display cache stats (default: 30s).  Set to 0 to disable stats collection and logging
 * `watch_retry_interval` - The time interval in seconds for retry backoffs when watch connections fail. (default: `10`)
 
 

lib/fluent/plugin/filter_kubernetes_metadata.rb

@@ -170,7 +170,12 @@ def configure(conf)
 
       require 'kubeclient'
       require 'lru_redux'
+
       @stats = KubernetesMetadata::Stats.new
+      if @stats_interval <= 0
+        @stats = KubernetesMetadata::NoOpStats.new
+        self.define_singleton_method(:dump_stats) {}
+      end
 
       if @cache_ttl < 0
         log.info 'Setting the cache TTL to :none because it was <= 0'
@@ -347,6 +352,7 @@ def filter(tag, time, record)
                                                 time, batch_miss_cache, record['docker']['container_id']))
         metadata = k_metadata
       end
+      dump_stats
       metadata ? record.merge(metadata) : record
     end
 

lib/fluent/plugin/kubernetes_metadata_stats.rb

@@ -43,4 +43,20 @@ def to_s
       end.join(', ')
     end
   end
+  class NoOpStats
+    def initialize
+    end
+
+    def bump(key)
+    end
+
+    def set(key, value)
+    end
+
+    def [](key)
+    end
+
+    def to_s
+    end
+  end
 end

test/plugin/test_filter_kubernetes_metadata.rb

@@ -41,6 +41,24 @@ def create_driver(conf = '')
       assert_equal(1000, d.instance.cache_size)
     end
 
+    sub_test_case 'stats_interval' do
+
+      test 'enables stats when greater than zero' do
+        d = create_driver('stats_interval 1')
+        assert_equal(1, d.instance.stats_interval)
+        d.instance.dump_stats
+        assert_false(d.instance.instance_variable_get("@curr_time").nil?)
+      end
+
+      test 'disables stats when <= zero' do
+        d = create_driver('stats_interval 0')
+        assert_equal(0, d.instance.stats_interval)
+         d.instance.dump_stats
+        assert_nil(d.instance.instance_variable_get("@curr_time"))
+      end
+
+    end
+
     test 'check test_api_adapter' do
       d = create_driver('test_api_adapter KubernetesMetadata::TestApiAdapter')
       assert_equal('KubernetesMetadata::TestApiAdapter', d.instance.test_api_adapter)
@@ -620,6 +638,7 @@ def emit_with_tag(tag, msg = {}, config = '
           kubernetes_url https://localhost:8443
           watch false
           cache_size 1
+          stats_interval 0
         ')
         d.run do
           d.feed(VAR_LOG_CONTAINER_TAG, msgpack_stream)