eee8598ff9
Automatic merge from submit-queue (batch tested with PRs 44337, 45775, 45832, 45574, 45758) Refactor gcr.io/google_containers/elasticsearch to alpine **What this PR does / why we need it**: This reduces the image size of the gcr.io/google_containers/elasticsearch image. Before: ``` REPOSITORY TAG IMAGE ID CREATED SIZE gcr.io/google_containers/elasticsearch v2.4.1-2 6941e43df81a 4 weeks ago 419MB ``` After: ``` REPOSITORY TAG IMAGE ID CREATED SIZE gcr.io/google_containers/elasticsearch v2.4.1-2 24ad40c21a52 About an hour ago 178MB ``` **Special notes for your reviewer**: I used a workaround to make the elasticsearch_logging_discovery binary work with alpine. (See [stackoverflow](https://stackoverflow.com/questions/34729748/installed-go-binary-not-found-in-path-on-alpine-linux-docker/35613430#35613430)). Alternatively this can be solved by setting ```CGO_ENABLED=0```when compiling the binary. I didn't feel comfortable chaing the Makefile though, since I'm no golang expert. Feedback wanted!
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.