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37 lines
1.7 KiB
Markdown
37 lines
1.7 KiB
Markdown
# Legacy Cluster add-ons
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For more information on add-ons see [the documentation](https://kubernetes.io/docs/concepts/cluster-administration/addons/).
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## Overview
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Cluster add-ons are resources like Services and Deployments (with pods) that are
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shipped with the Kubernetes binaries and are considered an inherent part of the
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Kubernetes clusters.
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There are currently two classes of add-ons:
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- Add-ons that will be reconciled.
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- Add-ons that will be created if they don't exist.
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More details could be found in [addon-manager/README.md](addon-manager/README.md).
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## Cooperating Horizontal / Vertical Auto-Scaling with "reconcile class addons"
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"Reconcile" class addons will be periodically reconciled to the original state given
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by the initial config. In order to make Horizontal / Vertical Auto-scaling functional,
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the related fields in config should be left unset. More specifically, leave `replicas`
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in `ReplicationController` / `Deployment` / `ReplicaSet` unset for Horizontal Scaling,
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leave `resources` for container unset for Vertical Scaling. The periodic reconcile
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won't clobbered these fields, hence they could be managed by Horizontal / Vertical
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Auto-scaler.
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## Add-on naming
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The suggested naming for most of the resources is `<basename>` (with no version number).
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Though resources like `Pod`, `ReplicationController` and `DaemonSet` are exceptional.
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It would be hard to update `Pod` because many fields in `Pod` are immutable. For
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`ReplicationController` and `DaemonSet`, in-place update may not trigger the underlying
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pods to be re-created. You probably need to change their names during update to trigger
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a complete deletion and creation.
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[]()
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