Merge pull request #24559 from derekwaynecarr/eviction_flags

Automatic merge from submit-queue

Add kubelet flags for eviction threshold configuration

This PR just adds the flags for kubelet eviction and the associated generated code.

I am happy to tweak text, but we can also do that later at this point in the release.

Since this causes codegen, I wanted to stage this first.

/cc @vishh @kubernetes/sig-node

cmd/kubelet/app/options/options.go

@@ -254,4 +254,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.NodeIP, "node-ip", s.NodeIP, "IP address of the node. If set, kubelet will use this IP address for the node")
 	fs.BoolVar(&s.EnableCustomMetrics, "enable-custom-metrics", s.EnableCustomMetrics, "Support for gathering custom metrics.")
 	fs.StringVar(&s.RuntimeCgroups, "runtime-cgroups", s.RuntimeCgroups, "Optional absolute name of cgroups to create and run the runtime in.")
+	fs.StringVar(&s.EvictionHard, "eviction-hard", s.EvictionHard, "A set of eviction thresholds (e.g. memory.available<1Gi) that if met would trigger a pod eviction.")
+	fs.StringVar(&s.EvictionSoft, "eviction-soft", s.EvictionSoft, "A set of eviction thresholds (e.g. memory.available<1.5Gi) that if met over a corresponding grace period would trigger a pod eviction.")
+	fs.StringVar(&s.EvictionSoftGracePeriod, "eviction-soft-grace-period", s.EvictionSoftGracePeriod, "A set of eviction grace periods (e.g. memory.available=1m30s) that correspond to how long a soft eviction threshold must hold before triggering a pod eviction.")
 }

docs/admin/kubelet.md

@@ -87,6 +87,9 @@ kubelet
       --enable-server[=true]: Enable the Kubelet's server
       --event-burst=10: Maximum size of a bursty event records, temporarily allows event records to burst to this number, while still not exceeding event-qps. Only used if --event-qps > 0
       --event-qps=5: If > 0, limit event creations per second to this value. If 0, unlimited.
+      --eviction-hard="": A set of eviction thresholds (e.g. memory.available<1Gi) that if met would trigger a pod eviction.
+      --eviction-soft="": A set of eviction thresholds (e.g. memory.available<1.5Gi) that if met over a corresponding grace period would trigger a pod eviction.
+      --eviction-soft-grace-period="": A set of eviction grace periods (e.g. memory.available=1m30s) that correspond to how long a soft eviction threshold must hold before triggering a pod eviction.
       --experimental-flannel-overlay[=false]: Experimental support for starting the kubelet with the default overlay network (flannel). Assumes flanneld is already running in client mode. [default=false]
       --file-check-frequency=20s: Duration between checking config files for new data
       --google-json-key="": The Google Cloud Platform Service Account JSON Key to use for authentication.

hack/verify-flags/known-flags.txt

@@ -116,6 +116,9 @@ etcd-servers-overrides
 event-burst
 event-qps
 event-ttl
+eviction-hard
+eviction-soft
+eviction-soft-grace-period
 executor-bindall
 executor-logv
 executor-path

pkg/apis/componentconfig/deep_copy_generated.go

@@ -302,6 +302,9 @@ func DeepCopy_componentconfig_KubeletConfiguration(in KubeletConfiguration, out
 	}
 	out.NonMasqueradeCIDR = in.NonMasqueradeCIDR
 	out.EnableCustomMetrics = in.EnableCustomMetrics
+	out.EvictionHard = in.EvictionHard
+	out.EvictionSoft = in.EvictionSoft
+	out.EvictionSoftGracePeriod = in.EvictionSoftGracePeriod
 	return nil
 }
 

pkg/apis/componentconfig/types.go

@@ -341,6 +341,12 @@ type KubeletConfiguration struct {
 	NonMasqueradeCIDR string `json:"nonMasqueradeCIDR"`
 	// enable gathering custom metrics.
 	EnableCustomMetrics bool `json:"enableCustomMetrics"`
+	// Comma-delimited list of hard eviction expressions.  For example, 'memory.available<300Mi'.
+	EvictionHard string `json:"evictionHard,omitempty"`
+	// Comma-delimited list of soft eviction expressions.  For example, 'memory.available<300Mi'.
+	EvictionSoft string `json:"evictionSoft,omitempty"`
+	// Comma-delimeted list of grace periods for each soft eviction signal.  For example, 'memory.available=30s'.
+	EvictionSoftGracePeriod string `json:"evictionSoftGracePeriod,omitempty"`
 }
 
 type KubeSchedulerConfiguration struct {