Update to Kubernetes v1.18

[mikkeloscar]

Introduce Kubernetes v1.18: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#changelog-since-v1170

Changes

• EndpointSlice feature gate is enabled by default in 1.18 (We still disable it by default)
• EndpointSlicePorxying can be enabled, disabled by default (Creating new EndpointSliceProxying feature gate for kube-proxy, enabling EndpointSlice feature gate by default kubernetes/kubernetes#86137)
• EvenPodsSpread is disabled by default (It was enabled in v1.18, but we don't support it in the autoscaler yet)

Features

• Now possible to configure scaling behavior on each HPA: https://kubernetes.io/docs/tasks/run-application/horizontal-pod-autoscale/#support-for-configurable-scaling-behavior
  • Document with relevant examples!
• kubectl debug (ephemeral containers)
  • Document feature
• Adds support for StartupProbes: https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/20190221-livenessprobe-holdoff.md
  • Document/mention feature (docs)
• Changes to Ingress
  • IngressClass field (Only relevant for OSS)
    • Add support in skipper (kubernetes: Add support for IngressClass introduced in Kubernetes v1.18 zalando/skipper#1478)
    • Add support in kube-ingress-aws-controller (Add support for IngressClass introduced in Kubernetes v1.18 kube-ingress-aws-controller#357)
  • pathType field
    • Add support in skipper (kubernetes: Add support for new ingress resource field pathType added in Kubernetes v1.18 zalando/skipper#1477)

TODO

• Apiserver added a new flag --goaway-chance which is the fraction of requests that will be closed gracefully(GOAWAY) to prevent HTTP/2 clients from getting stuck on a single apiserver.
• Pause image upgraded to 3.2 in kubelet and kubeadm
• READ THIS: https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.18.md#other-bug-cleanup-or-flake-1

[mikkeloscar]

👍

[jrake-revelant]

👍