Deprecate node-selector, max-pods-to-evict-per-node and evict-local-storage-pods flags and promote then to policy v1alpha1 fields

README.md

@@ -64,6 +64,21 @@ Seven strategies `RemoveDuplicates`, `LowNodeUtilization`, `RemovePodsViolatingI
 are currently implemented. As part of the policy, the parameters associated with the strategies can be configured too.
 By default, all strategies are enabled.
 
+The policy also includes common configuration for all the strategies:
+- `nodeSelector` - limiting the nodes which are processed
+- `evictLocalStoragePods` - allowing to evict pods with local storage
+- `maxNoOfPodsToEvictPerNode` - maximum number of pods evicted from each node (summed through all strategies)
+
+```
+apiVersion: "descheduler/v1alpha1"
+kind: "DeschedulerPolicy"
+nodeSelector: prod=dev
+evictLocalStoragePods: true
+maxNoOfPodsToEvictPerNode: 40
+strategies:
+  ...
+```
+
 ### RemoveDuplicates
 
 This strategy makes sure that there is only one pod associated with a Replica Set (RS),

cmd/descheduler/app/options/options.go

@@ -53,9 +53,9 @@ func (rs *DeschedulerServer) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&rs.PolicyConfigFile, "policy-config-file", rs.PolicyConfigFile, "File with descheduler policy configuration.")
 	fs.BoolVar(&rs.DryRun, "dry-run", rs.DryRun, "execute descheduler in dry run mode.")
 	// node-selector query causes descheduler to run only on nodes that matches the node labels in the query
-	fs.StringVar(&rs.NodeSelector, "node-selector", rs.NodeSelector, "Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")
+	fs.StringVar(&rs.NodeSelector, "node-selector", rs.NodeSelector, "DEPRECATED: selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")
 	// max-no-pods-to-evict limits the maximum number of pods to be evicted per node by descheduler.
-	fs.IntVar(&rs.MaxNoOfPodsToEvictPerNode, "max-pods-to-evict-per-node", rs.MaxNoOfPodsToEvictPerNode, "Limits the maximum number of pods to be evicted per node by descheduler")
+	fs.IntVar(&rs.MaxNoOfPodsToEvictPerNode, "max-pods-to-evict-per-node", rs.MaxNoOfPodsToEvictPerNode, "DEPRECATED: limits the maximum number of pods to be evicted per node by descheduler")
 	// evict-local-storage-pods allows eviction of pods that are using local storage. This is false by default.
-	fs.BoolVar(&rs.EvictLocalStoragePods, "evict-local-storage-pods", rs.EvictLocalStoragePods, "Enables evicting pods using local storage by descheduler")
+	fs.BoolVar(&rs.EvictLocalStoragePods, "evict-local-storage-pods", rs.EvictLocalStoragePods, "DEPRECATED: enables evicting pods using local storage by descheduler")
 }

docs/user-guide.md

@@ -21,11 +21,11 @@ Available Commands:
   version     Version of descheduler
 
 Flags:
-      --add-dir-header                   If true, adds the file directory to the header
+      --add-dir-header                   If true, adds the file directory to the header of the log messages
       --alsologtostderr                  log to standard error as well as files
       --descheduling-interval duration   Time interval between two consecutive descheduler executions. Setting this value instructs the descheduler to run in a continuous loop at the interval specified.
       --dry-run                          execute descheduler in dry run mode.
-      --evict-local-storage-pods         Enables evicting pods using local storage by descheduler
+      --evict-local-storage-pods         DEPRECATED: enables evicting pods using local storage by descheduler
   -h, --help                             help for descheduler
       --kubeconfig string                File with  kube configuration.
       --log-backtrace-at traceLocation   when logging hits line file:N, emit a stack trace (default :0)
@@ -34,8 +34,8 @@ Flags:
       --log-file-max-size uint           Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited. (default 1800)
       --log-flush-frequency duration     Maximum number of seconds between log flushes (default 5s)
       --logtostderr                      log to standard error instead of files (default true)
-      --max-pods-to-evict-per-node int   Limits the maximum number of pods to be evicted per node by descheduler
-      --node-selector string             Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)
+      --max-pods-to-evict-per-node int   DEPRECATED: limits the maximum number of pods to be evicted per node by descheduler
+      --node-selector string             DEPRECATED: selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)
       --policy-config-file string        File with descheduler policy configuration.
       --skip-headers                     If true, avoid header prefixes in the log messages
       --skip-log-headers                 If true, avoid headers when opening log files
@@ -88,10 +88,10 @@ strategies:
 ```
 
 ### Autoheal Node Problems
-Descheduler's `RemovePodsViolatingNodeTaints` strategy can be combined with 
+Descheduler's `RemovePodsViolatingNodeTaints` strategy can be combined with
 [Node Problem Detector](https://github.com/kubernetes/node-problem-detector/) and
 [Cluster Autoscaler](https://github.com/kubernetes/autoscaler/tree/master/cluster-autoscaler) to automatically remove
 Nodes which have problems. Node Problem Detector can detect specific Node problems and taint any Nodes which have those
-problems. The Descheduler will then deschedule workloads from those Nodes. Finally, if the descheduled Node's resource 
+problems. The Descheduler will then deschedule workloads from those Nodes. Finally, if the descheduled Node's resource
 allocation falls below the Cluster Autoscaler's scale down threshold, the Node will become a scale down candidate
 and can be removed by Cluster Autoscaler. These three components form an autohealing cycle for Node problems.

pkg/api/types.go

@@ -28,6 +28,15 @@ type DeschedulerPolicy struct {
 
 	// Strategies
 	Strategies StrategyList
+
+	// NodeSelector for a set of nodes to operate over
+	NodeSelector *string
+
+	// EvictLocalStoragePods allows pods using local storage to be evicted.
+	EvictLocalStoragePods *bool
+
+	// MaxNoOfPodsToEvictPerNode restricts maximum of pods to be evicted per node.
+	MaxNoOfPodsToEvictPerNode *int
 }
 
 type StrategyName string

pkg/api/v1alpha1/types.go

@@ -28,6 +28,15 @@ type DeschedulerPolicy struct {
 
 	// Strategies
 	Strategies StrategyList `json:"strategies,omitempty"`
+
+	// NodeSelector for a set of nodes to operate over
+	NodeSelector *string `json:"nodeSelector,omitempty"`
+
+	// EvictLocalStoragePods allows pods using local storage to be evicted.
+	EvictLocalStoragePods *bool `json:"evictLocalStoragePods,omitempty"`
+
+	// MaxNoOfPodsToEvictPerNode restricts maximum of pods to be evicted per node.
+	MaxNoOfPodsToEvictPerNode *int `json:"maxNoOfPodsToEvictPerNode,omitempty"`
 }
 
 type StrategyName string

pkg/descheduler/descheduler.go

@@ -20,7 +20,7 @@ import (
 	"context"
 	"fmt"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/klog/v2"
 
@@ -79,8 +79,23 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 		"PodLifeTime":                             strategies.PodLifeTime,
 	}
 
+	nodeSelector := rs.NodeSelector
+	if deschedulerPolicy.NodeSelector != nil {
+		nodeSelector = *deschedulerPolicy.NodeSelector
+	}
+
+	evictLocalStoragePods := rs.EvictLocalStoragePods
+	if deschedulerPolicy.EvictLocalStoragePods != nil {
+		evictLocalStoragePods = *deschedulerPolicy.EvictLocalStoragePods
+	}
+
+	maxNoOfPodsToEvictPerNode := rs.MaxNoOfPodsToEvictPerNode
+	if deschedulerPolicy.MaxNoOfPodsToEvictPerNode != nil {
+		maxNoOfPodsToEvictPerNode = *deschedulerPolicy.MaxNoOfPodsToEvictPerNode
+	}
+
 	wait.Until(func() {
-		nodes, err := nodeutil.ReadyNodes(ctx, rs.Client, nodeInformer, rs.NodeSelector, stopChannel)
+		nodes, err := nodeutil.ReadyNodes(ctx, rs.Client, nodeInformer, nodeSelector, stopChannel)
 		if err != nil {
 			klog.V(1).Infof("Unable to get ready nodes: %v", err)
 			close(stopChannel)
@@ -97,9 +112,9 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 			rs.Client,
 			evictionPolicyGroupVersion,
 			rs.DryRun,
-			rs.MaxNoOfPodsToEvictPerNode,
+			maxNoOfPodsToEvictPerNode,
 			nodes,
-			rs.EvictLocalStoragePods,
+			evictLocalStoragePods,
 		)
 
 		for name, f := range strategyFuncs {