Evictor¶

Install Evictor¶

Evictor will compact your pods into fewer nodes, creating empty nodes that will be removed by the Node deletion policy. To install Evictor fo the first time run this command:

helm repo add castai https://castai.github.io/official-addons
helm -n kube-system upgrade -i evictor castai/evictor --set dryRun=false

This process will take some time. Also, by default, Evictor will not cause any downtime to single replica deployments / StatefulSets, pods without ReplicaSet, meaning that those nodes can't be removed gracefully. Familiarize with rules and available overrides in order to setup Evictor to meet your needs.

Upgrading Evictor¶

Check the Evictor version you are currently using:
```
helm ls -n kube-system
```
Update the helm chart repository to make sure that your helm command is aware of the latest charts:
```
helm repo update
```

Install the latest Evictor version:

helm -n kube-system upgrade -i evictor castai/evictor --set dryRun=false

Check whether the Evictor version was changed:
```
helm ls -n kube-system
```

Avoiding downtime during Bin-Packing¶

Evictor follows certain rules to avoid downtime. In order for the node to be considered for possible removal due to bin-packing, all of the pods running on the node must meet following criteria:

A pod must be replicated: it should be managed by a Controller (e.g. ReplicaSet, ReplicationController, Deployment), which has more than one replicas (see Overrides)
A pod is not part of StatefulSet
A pod must not be marked as non-evictable (see Overrides)
All static pods (YAMLs defined in node's /etc/kubernetes/manifests by default) are considered evictable
All DaemonSet-controller pods are considered evictable

Rules override for specific pods or nodes¶

Name	Value	Type (`Annotation` or `Label`)	Location (`Pod` or `Node`)	Effect
`beta.evictor.cast.ai/eviction-disabled`	`"true"`	`Annotation`on`Pod`, but can be both`label`and`annotation`on`Node`	Both`Pod`and`Node`	Evictor won't try to Evict a Node with this Annotation or Node running Pod annotated with this Annotation.
`autoscaling.cast.ai/removal-disabled`	`"true"`	Both	`Node`	Evictor won't try to Evict a Node marked with this`Annotation`or`Label`
`beta.evictor.cast.ai/disposable`	`"true"`	`Annotation`	`Pod`	Evictor will treat this`Pod` as Evictable despite any of the other rules defined in Rules