bug 1814547: Rebase upstream 1.18

.gitignore

@@ -2,4 +2,4 @@ _output/
 _tmp/
 vendordiff.patch
 .idea/
-
+*.code-workspace

README.md

@@ -54,9 +54,9 @@ See the [user guide](docs/user-guide.md) in the `/docs` directory.
 ## Policy and Strategies
 
 Descheduler's policy is configurable and includes strategies that can be enabled or disabled.
-Five strategies `RemoveDuplicates`, `LowNodeUtilization`, `RemovePodsViolatingInterPodAntiAffinity`,
-`RemovePodsViolatingNodeAffinity`, and `RemovePodsViolatingNodeTaints` are currently implemented.
-As part of the policy, the parameters associated with the strategies can be configured too.
+Seven strategies `RemoveDuplicates`, `LowNodeUtilization`, `RemovePodsViolatingInterPodAntiAffinity`,
+`RemovePodsViolatingNodeAffinity`, `RemovePodsViolatingNodeTaints`, `RemovePodsHavingTooManyRestarts`, and `PodLifeTime`
+are currently implemented. As part of the policy, the parameters associated with the strategies can be configured too.
 By default, all strategies are enabled.
 
 ### RemoveDuplicates
@@ -66,15 +66,21 @@ Replication Controller (RC), Deployment, or Job running on the same node. If the
 those duplicate pods are evicted for better spreading of pods in a cluster. This issue could happen
 if some nodes went down due to whatever reasons, and pods on them were moved to other nodes leading to
 more than one pod associated with a RS or RC, for example, running on the same node. Once the failed nodes
-are ready again, this strategy could be enabled to evict those duplicate pods. Currently, there are no
-parameters associated with this strategy. To disable this strategy, the policy should look like:
+are ready again, this strategy could be enabled to evict those duplicate pods.
+
+It provides one optional parameter, `ExcludeOwnerKinds`, which is a list of OwnerRef `Kind`s. If a pod
+has any of these `Kind`s listed as an `OwnerRef`, that pod will not be considered for eviction.
 
 ```
 apiVersion: "descheduler/v1alpha1"
 kind: "DeschedulerPolicy"
 strategies:
   "RemoveDuplicates":
-     enabled: false
+     enabled: true
+     params:
+       removeDuplicates:
+         excludeOwnerKinds:
+         - "ReplicaSet"
 ```
 
 ### LowNodeUtilization
@@ -198,6 +204,21 @@ strategies:
          includingInitContainers: true
 ```
 
+### PodLifeTime
+
+This strategy evicts pods that are older than `.strategies.PodLifeTime.params.maxPodLifeTimeSeconds` The policy
+file should look like:
+
+````
+apiVersion: "descheduler/v1alpha1"
+kind: "DeschedulerPolicy"
+strategies:
+  "PodLifeTime":
+     enabled: true
+     params:
+        maxPodLifeTimeSeconds: 86400
+````
+
 ## Pod Evictions
 
 When the descheduler decides to evict pods from a node, it employs the following general mechanism:
@@ -265,7 +286,6 @@ Learn how to engage with the Kubernetes community on the [community page](http:/
 This roadmap is not in any particular order.
 
 * Consideration of pod affinity
-* Strategy to consider pod life time
 * Strategy to consider number of pending pods
 * Integration with cluster autoscaler
 * Integration with metrics providers for obtaining real load metrics

docs/user-guide.md

@@ -5,8 +5,10 @@ Starting with descheduler release v0.10.0 container images are available in thes
 * `eu.gcr.io/k8s-artifacts-prod/descheduler/descheduler`
 * `us.gcr.io/k8s-artifacts-prod/descheduler/descheduler`
 
+## Policy Configuration Examples
 The [examples](https://github.com/kubernetes-sigs/descheduler/tree/master/examples) directory has descheduler policy configuration examples.
 
+## CLI Options
 The descheduler has many CLI options that can be used to override its default behavior.
 ```
 descheduler --help
@@ -44,4 +46,45 @@ Flags:
       --vmodule moduleSpec               comma-separated list of pattern=N settings for file-filtered logging
 
 Use "descheduler [command] --help" for more information about a command.
-```
+```
+
+## Production Use Cases
+This section contains descriptions of real world production use cases.
+
+### Balance Cluster By Pod Age
+When initially migrating applications from a static virtual machine infrastructure to a cloud native k8s
+infrastructure there can be a tendency to treat application pods like static virtual machines. One approach
+to help prevent developers and operators from treating pods like virtual machines is to ensure that pods
+only run for a fixed amount
+of time.
+
+The `PodLifeTime` strategy can be used to ensure that old pods are evicted. It is recommended to create a
+[pod disruption budget](https://kubernetes.io/docs/tasks/run-application/configure-pdb/) for each
+application to ensure application availability.
+```
+descheduler -v=3 --evict-local-storage-pods --policy-config-file=pod-life-time.yml
+```
+
+This policy configuration file ensures that pods created more than 7 days ago are evicted.
+```
+---
+apiVersion: "descheduler/v1alpha1"
+kind: "DeschedulerPolicy"
+strategies:
+  "LowNodeUtilization":
+    enabled: false
+  "RemoveDuplicates":
+    enabled: false
+  "RemovePodsViolatingInterPodAntiAffinity":
+    enabled: false
+  "RemovePodsViolatingNodeAffinity":
+    enabled: false
+  "RemovePodsViolatingNodeTaints":
+    enabled: false
+  "RemovePodsHavingTooManyRestarts":
+    enabled: false
+  "PodLifeTime":
+    enabled: true
+    params:
+      maxPodLifeTimeSeconds: 604800 # pods run for a maximum of 7 days
+```

examples/pod-life-time.yml

@@ -0,0 +1,20 @@
+---
+apiVersion: "descheduler/v1alpha1"
+kind: "DeschedulerPolicy"
+strategies:
+  "LowNodeUtilization":
+    enabled: false
+  "RemoveDuplicates":
+    enabled: false
+  "RemovePodsViolatingInterPodAntiAffinity":
+    enabled: false
+  "RemovePodsViolatingNodeAffinity":
+    enabled: false
+  "RemovePodsViolatingNodeTaints":
+    enabled: false
+  "RemovePodsHavingTooManyRestarts":
+    enabled: false
+  "PodLifeTime":
+    enabled: true
+    params:
+      maxPodLifeTimeSeconds: 604800 # 7 days

go.mod

@@ -3,15 +3,12 @@ module sigs.k8s.io/descheduler
 go 1.13
 
 require (
-	github.com/gogo/protobuf v1.3.1 // indirect
 	github.com/spf13/cobra v0.0.5
 	github.com/spf13/pflag v1.0.5
-	k8s.io/api v0.17.0
-	k8s.io/apimachinery v0.17.3-beta.0
-	k8s.io/apiserver v0.17.0
-	k8s.io/client-go v0.17.0
-	k8s.io/component-base v0.17.0
+	k8s.io/api v0.18.2
+	k8s.io/apimachinery v0.18.2
+	k8s.io/apiserver v0.18.2
+	k8s.io/client-go v0.18.2
+	k8s.io/component-base v0.18.2
 	k8s.io/klog v1.0.0
-	k8s.io/kube-openapi v0.0.0-20200121204235-bf4fb3bd569c // indirect
-	sigs.k8s.io/yaml v1.2.0 // indirect
 )