04b3ab9aba
Automatic merge from submit-queue (batch tested with PRs 50932, 49610, 51312, 51415, 50705) Allow running kube-proxy as a DaemonSet when using kube-up.sh on GCE **What this PR does / why we need it**: From #23225, this PR adds an option for user to run kube-proxy as a DaemonSet instead of static pods using GCE startup scripts. By default, kube-proxy will run as static pods. This is the first step for moving kube-proxy into a DaemonSet in GCE, remaining tasks will be tracked on #23225. **Special notes for your reviewer**: The last commit are purely for testing out kube-proxy as daemonset via CIs. cc @kubernetes/sig-network-misc @kubernetes/sig-cluster-lifecycle-misc **Release note**: ```release-note When using kube-up.sh on GCE, user could set env `KUBE_PROXY_DAEMONSET=true` to run kube-proxy as a DaemonSet. kube-proxy is run as static pods by default. ```
Cluster add-ons
Overview
Cluster add-ons are resources like Services and Deployments (with pods) that are shipped with the Kubernetes binaries and are considered an inherent part of the Kubernetes clusters.
There are currently two classes of add-ons:
- Add-ons that will be reconciled.
- Add-ons that will be created if they don't exist.
More details could be found in addon-manager/README.md.
Cooperating Horizontal / Vertical Auto-Scaling with "reconcile class addons"
"Reconcile" class addons will be periodically reconciled to the original state given
by the initial config. In order to make Horizontal / Vertical Auto-scaling functional,
the related fields in config should be left unset. More specifically, leave replicas
in ReplicationController / Deployment / ReplicaSet unset for Horizontal Scaling,
leave resources for container unset for Vertical Scaling. The periodic reconcile
won't clobbered these fields, hence they could be managed by Horizontal / Vertical
Auto-scaler.
Add-on naming
The suggested naming for most of the resources is <basename> (with no version number).
Though resources like Pod, ReplicationController and DaemonSet are exceptional.
It would be hard to update Pod because many fields in Pod are immutable. For
ReplicationController and DaemonSet, in-place update may not trigger the underlying
pods to be re-created. You probably need to change their names during update to trigger
a complete deletion and creation.