karmada/docs/userguide/configure-controllers.md

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Configure Controllers

Karmada maintains a bunch of controllers which are control loops that watch the state of your system, then make or request changes where needed. Each controller tries to move the current state closer to the desired state. See Kubernetes Controller Concepts for more details.

Karmada Controllers

The controllers are embedded into components of karmada-controller-manager or karmada-agent and will be launched
along with components startup. Some controllers may be shared by karmada-controller-manager and karmada-agent.

Controller In karmada-controller-manager In karmada-agent
cluster Y N
clusterStatus Y Y
binding Y N
execution Y Y
workStatus Y Y
namespace Y N
serviceExport Y Y
endpointSlice Y N
serviceImport Y N
unifiedAuth Y N
hpa Y N

Configure Karmada Controllers

You can use --controllers flag to specify the enabled controller list for karmada-controller-manager and karmada-agent, or disable some of them in addition to the default list.

E.g. Specify a controller list:

--controllers=cluster,clusterStatus,binding,xxx

E.g. Disable some controllers:

--controllers=-hpa,-unifiedAuth

Use -foo to disable the controller named foo.

Note: The default controller list might be changed in the future releases. The controllers enabled in the last release might be disabled or deprecated and new controllers might be introduced too. Users who are using this flag should check the release notes before system upgrade.

Kubernetes Controllers

In addition to the controllers that are maintained by the Karmada community, Karmada also requires some controllers from Kubernetes. These controllers run as part of kube-controller-manager and are maintained by the Kubernetes community.

Users are recommended to deploy the kube-controller-manager along with Karmada components. And the installation methods list in installation guide would help you deploy it as well as Karmada components.

Not all controllers in kube-controller-manager are necessary for Karmada, if you are deploying Karmada using other tools, you might have to configure the controllers by --controllers flag just like what we did in example of kube-controller-manager deployment.

The following controllers are tested and recommended by Karmada.

namespace

TODO.

garbagecollector

TODO.

serviceaccount-token

The serviceaccount-token controller runs as part of kube-controller-manager. It watches ServiceAccount creation and creates a corresponding ServiceAccount token Secret to allow API access.

For the Karmada control plane, after a ServiceAccount object is created by the administrator, we also need serviceaccount-token controller to generate the ServiceAccount token Secret, which will be a relief for administrator as he/she doesn't need to manually prepare the token.

More details please refer to: