docs for resourceVersion (#258)

fabric8io · Oct 8, 2020 · 84f66a8 · 84f66a8
1 parent f65617d
commit 84f66a8
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/lib/fluent/plugin/kubernetes_metadata_watch_namespaces.rb b/lib/fluent/plugin/kubernetes_metadata_watch_namespaces.rb
@@ -16,6 +16,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# TODO: this is mostly copy-paste from kubernetes_metadata_watch_pods.rb unify them
 require_relative 'kubernetes_metadata_common'
 
 module KubernetesMetadata
@@ -89,15 +90,18 @@ def start_namespace_watch
     # starting from that resourceVersion.
     def get_namespaces_and_start_watcher
       options = {
-        resource_version: '0'  # Fetch from API server.
+        resource_version: '0'  # Fetch from API server cache instead of etcd quorum read
       }
       namespaces = @client.get_namespaces(options)
       namespaces[:items].each do |namespace|
         cache_key = namespace[:metadata][:uid]
         @namespace_cache[cache_key] = parse_namespace_metadata(namespace)
         @stats.bump(:namespace_cache_host_updates)
       end
+
+      # continue watching from most recent resourceVersion
       options[:resource_version] = namespaces[:metadata][:resourceVersion]
+
       @client.watch_namespaces(options)
     end
 

diff --git a/lib/fluent/plugin/kubernetes_metadata_watch_pods.rb b/lib/fluent/plugin/kubernetes_metadata_watch_pods.rb
@@ -16,6 +16,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# TODO: this is mostly copy-paste from kubernetes_metadata_watch_namespaces.rb unify them
 require_relative 'kubernetes_metadata_common'
 
 module KubernetesMetadata
@@ -91,7 +92,7 @@ def start_pod_watch
     # from that resourceVersion.
     def get_pods_and_start_watcher
       options = {
-        resource_version: '0'  # Fetch from API server.
+        resource_version: '0'  # Fetch from API server cache instead of etcd quorum read
       }
       if ENV['K8S_NODE_NAME']
         options[:field_selector] = 'spec.nodeName=' + ENV['K8S_NODE_NAME']
@@ -105,6 +106,8 @@ def get_pods_and_start_watcher
           @cache[cache_key] = parse_pod_metadata(pod)
           @stats.bump(:pod_cache_host_updates)
         end
+
+        # continue watching from most recent resourceVersion
         options[:resource_version] = pods[:metadata][:resourceVersion]
       end
       @client.watch_pods(options)