OpenShift Major changes coming with 4.0

Hawkular

Replaced by Prometheus monitoring.

Cassandra

Replaced by Prometheus monitoring.

Heapster

Replaced by Metrics-Server or Prometheus metrics adapter.

Atomic Host

Replaced by Red Hat CoreOS.

System containers

Replaced by Red Hat CoreOS.

projectatomic/docker-1.13 additional search registries

CRI-O is the default container runtime for 4.x on RHCOS and Red Hat Enterprise Linux.

oc adm diagnostics

Operator-based diagnostics.

oc adm registry

Replaced by the registry operator.

Custom Docker Build Strategy on Builder Pods

If you want to continue using custom builds, you must replace your Docker invocations with Podman and Buildah. The custom build strategy will not be removed, but the functionality will change significantly in OpenShift Container Platform 4.0.

Cockpit

Replaced by Quay.

Standalone Registry Installations

Quay is our enterprise container image registry.

DNSmasq

CoreDNS will be the default.

External etcd nodes

For 4.0, etcd is on the cluster always.

CloudForms OpenShift Provider and Podified CloudForms

Replaced by built-in management tooling.

Volume Provisioning via installer

Replaced by dynamic volumes or, if NFS is required, NFS provisioner.

blue-green-installation method

Ease of upgrade is a core value of 4.0.