Direct Connection
If the kube-apiserver address of the member cluster is accessible on any node of the host cluster, you can adopt Direction Connection. This method is applicable when the kube-apiserver address of the member cluster can be exposed or host cluster and member cluster are in the same private network or subnet.
To use the multi-cluster feature using direct connection, you must have at least two clusters serving as the host cluster and the member cluster respectively. A cluster can be defined as the host cluster or the member cluster either before or after you install KubeSphere. For more information about installing KubeSphere, refer to Installing on Linux and Installing on Kubernetes.
Video Demonstration
Prepare a Host Cluster
A host cluster provides you with the central control plane and you can only define one host cluster.
If you already have a standalone KubeSphere cluster installed, you can set the value of clusterRole
to host
by editing the cluster configuration.
Option A - Use the web console:
Use the
admin
account to log in to the console and go to CRDs on the Cluster Management page. Enter the keywordClusterConfiguration
and go to its detail page. Edit the YAML ofks-installer
, which is similar to Enable Pluggable Components.Option B - Use Kubectl:
kubectl edit cc ks-installer -n kubesphere-system
In the YAML file of ks-installer
, navigate to multicluster
, set the value of clusterRole
to host
, then click OK (if you use the web console) to make it effective:
multicluster:
clusterRole: host
To set the host cluster name, add a field hostClusterName
under multicluster.clusterRole
in the YAML file of ks-installer
:
multicluster:
clusterRole: host
hostClusterName: <Host cluster name>
Note
- It is recommended that you set the host cluster name while you are preparing your host cluster. When your host cluster is set up and running with resources deployed, it is not recommended that you set the host cluster name.
- The host cluster name can contain only lowercase letters, numbers, hyphens (-), or periods (.), and must start and end with a lowercase letter or number.
You need to wait for a while so that the change can take effect.
You can define a host cluster before you install KubeSphere either on Linux or on an existing Kubernetes cluster. If you want to install KubeSphere on Linux, you use a config-sample.yaml
file. If you want to install KubeSphere on an existing Kubernetes cluster, you use two YAML files, one of which is cluster-configuration.yaml
.
To set a host cluster, change the value of clusterRole
to host
in config-sample.yaml
or cluster-configuration.yaml
accordingly before you install KubeSphere.
multicluster:
clusterRole: host
To set the host cluster name, add a field hostClusterName
under multicluster.clusterRole
in config-sample.yaml
or cluster-configuration.yaml
:
multicluster:
clusterRole: host
hostClusterName: <Host cluster name>
Note
- The host cluster name can contain only lowercase letters, numbers, hyphens (-), or periods (.), and must start and end with a lowercase letter or number.
Info
config-sample.yaml
file. In this case, you can set a host cluster after KubeSphere is installed.You can use kubectl to retrieve the installation logs to verify the status by running the following command. Wait for a while, and you will be able to see the successful log return if the host cluster is ready.
kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l 'app in (ks-install, ks-installer)' -o jsonpath='{.items[0].metadata.name}') -f
Prepare a Member Cluster
In order to manage the member cluster from the host cluster, you need to make jwtSecret
the same between them. Therefore, get it first by excuting the following command on the host cluster.
kubectl -n kubesphere-system get cm kubesphere-config -o yaml | grep -v "apiVersion" | grep jwtSecret
The output may look like this:
jwtSecret: "gfIwilcc0WjNGKJ5DLeksf2JKfcLgTZU"
If you already have a standalone KubeSphere cluster installed, you can set the value of clusterRole
to member
by editing the cluster configuration.
Option A - Use the web console:
Use the
admin
account to log in to the console and go to CRDs on the Cluster Management page. Enter the keywordClusterConfiguration
and go to its detail page. Edit the YAML ofks-installer
, which is similar to Enable Pluggable Components.Option B - Use Kubectl:
kubectl edit cc ks-installer -n kubesphere-system
In the YAML file of ks-installer
, enter the corresponding jwtSecret
shown above:
authentication:
jwtSecret: gfIwilcc0WjNGKJ5DLeksf2JKfcLgTZU
Scroll down and set the value of clusterRole
to member
, then click OK (if you use the web console) to make it effective:
multicluster:
clusterRole: member
You need to wait for a while so that the change can take effect.
You can define a member cluster before you install KubeSphere either on Linux or on an existing Kubernetes cluster. If you want to install KubeSphere on Linux, you use a config-sample.yaml
file. If you want to install KubeSphere on an existing Kubernetes cluster, you use two YAML files, one of which is cluster-configuration.yaml
. To set a member cluster, enter the value of jwtSecret
shown above and change the value of clusterRole
to member
in config-sample.yaml
or cluster-configuration.yaml
accordingly before you install KubeSphere.
authentication:
jwtSecret: gfIwilcc0WjNGKJ5DLeksf2JKfcLgTZU
multicluster:
clusterRole: member
Note
config-sample.yaml
file. In this case, you can set a member cluster after KubeSphere is installed.You can use kubectl to retrieve the installation logs to verify the status by running the following command. Wait for a while, and you will be able to see the successful log return if the member cluster is ready.
kubectl logs -n kubesphere-system $(kubectl get pod -n kubesphere-system -l 'app in (ks-install, ks-installer)' -o jsonpath='{.items[0].metadata.name}') -f
Import a Member Cluster
Log in to the KubeSphere console as
admin
and click Add Cluster on the Cluster Management page.Enter the basic information of the cluster to be imported on the Import Cluster page. You can also click Edit Mode in the upper-right corner to view and edit the basic information in YAML format. After you finish editing, click Next.
In Connection Method, select Direct connection, and copy the kubeconfig of the member cluster and paste it into the box. You can also click Edit Mode in the upper-right corner to edit the kubeconfig of the member cluster in YAML format.
Note
Make sure theserver
address in KubeConfig is accessible on any node of the host cluster.Click Create and wait for cluster initialization to finish.
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