Each strategy implements a test for checking if a maximum number of pods per node
was already evicted. The test duplicates a code that can be put
under a single invocation. Thus, reducing the number of arguments passed
to each strategy given EvicPod call can encapsulate both the check
and the invocation of the pod eviction itself.
Only over utilized nodes need clasification of pods into categories.
Thus, skipping categorizing of pods which saves computation time in cases
where the number of over utilized nodes makes less than 50% of all nodes
or their fraction.
Compared to https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#node-affinity
the strategy kinda implements requiredDuringSchedulingRequiredDuringExecution node affinity type
for kubelets. Only addition to kubelet is the strategy checks whether is at least another node
capable of respecting the node affinity rules.
When requiredDuringSchedulingRequiredDuringExecution node affinity type is implemented in kubelet,
it's likely the strategy either gets removed or re-implemented. Stressing the relation with
requiredDuringSchedulingRequiredDuringExecution will helps consumers of descheduler
to keep in mind the kubelet will eventually take over the strategy when implemented.
Add a link to the test grid dashboard for automated container image builds,
and documents useful gcloud commands for woking with the staging registry.
This documentation is useful for project maintainers that are creating
releases and publishing container images. The chance of remembering
these commands and links is slim to none. Therefore documenting this
information will be very useful.
Based on feedback during code review it was recommended to allow
updating events in addition to creating events. Because event proceeding
logic on the client side sometimes updates existing events instead of
creating a new one.
Enable a build matrix in Travis CI to run the e2e tests against
multiple k8s versions. Additionally update kind to v0.7.0 which adds
support for k8s v1.17.
Replaced command "kind get kubeconfig-path" with "kind get kubeconfig"
because the "kubeconfig-path" subcommand is not valid with kind v0.7.0.
The descheduler creates a k8s event for each pod that it evicts. When
the code to create events was added the RBAC ClusterRole was not updated
to allow creating events. Users would see the below error in the
descheduler log when it tried to create an event.
"system:serviceaccount:kube-system:descheduler-sa" cannot create resource
"events" in API group "" in the namespace "xxxx-production"' (will not retry!)'
This change fixes this error by updating the ClusterRole to allow
creation of k8s events.
