Quick Start

This tutorial walks you through,

• setting up Clusternet locally with 1 parent cluster and 3 child clusters by using kind
• checking child clusters registration status
• deploying applications to multiple clusters

Prerequisites

• Helm
• kubectl
• kubectl plugin “clusternet”
• kind
• Docker

Some Known Issues

Pod errors due to “too many open files”

You may encounter that some pods fail to get running and the logs of these pods complain “too many open files”.

This may be caused by running out of inotify resources. Resource limits are defined by fs.inotify.max_user_watches and fs.inotify.max_user_instances system variables. For example, in Ubuntu these default to 8192 and 128 respectively, which is not enough to create multiple kind clusters with many pods.

To increase these limits temporarily run the following commands on the host:

sudo sysctl fs.inotify.max_user_watches=524288
sudo sysctl fs.inotify.max_user_instances=512

To make the changes persistent, edit the file /etc/sysctl.conf and add these lines:

fs.inotify.max_user_watches = 524288
fs.inotify.max_user_instances = 512

Clone Clusternet

Clone the repository,

mkdir -p $GOPATH/src/github.com/clusternet/
cd $GOPATH/src/github.com/clusternet/
git clone https://github.com/clusternet/clusternet
cd clusternet

Install Clusternet

Run the following script,

cd hack
./local-running.sh

If everything goes well, you will see the messages as follows:

Local clusternet is running now.
To start using clusternet, please run:
  export KUBECONFIG="${HOME}/.kube/clusternet.config"
  kubectl config get-contexts

When you run kubectl config get-contexts, you will see 1 parent cluster and 3 child clusters and the clusternet has been deployed automatically.

$ kubectl config get-contexts
CURRENT   NAME     CLUSTER       AUTHINFO      NAMESPACE
          child1   kind-child1   kind-child1   
          child2   kind-child2   kind-child2   
          child3   kind-child3   kind-child3   
*         parent   kind-parent   kind-parent
$ kubectl get pod -n clusternet-system
NAME                                            READY   STATUS    RESTARTS   AGE
clusternet-controller-manager-5b54d5f95-bnq8l   1/1     Running   0          2m
clusternet-controller-manager-5b54d5f95-kn6mw   1/1     Running   0          2m
clusternet-controller-manager-5b54d5f95-pkmc6   1/1     Running   0          2m
clusternet-hub-6c7bbcbd68-flbwm                 1/1     Running   0          2m3s
clusternet-hub-6c7bbcbd68-m4rkx                 1/1     Running   0          2m3s
clusternet-hub-6c7bbcbd68-rkw5c                 1/1     Running   0          2m3s
clusternet-scheduler-8675d64884-4r8rx           1/1     Running   0          2m1s
clusternet-scheduler-8675d64884-7nx5d           1/1     Running   0          2m1s
clusternet-scheduler-8675d64884-8c8f5           1/1     Running   0          2m1s

Checking Cluster Registration

Please follow this tutorial on checking cluster registration status.

Deploying Applications to Child Clusters

Please follow our interactive tutorials to deploy applications to above three child clusters from parent cluster. And the parent cluster can register itself as a child cluster as well, if you install clusternet-agent on it.