Clusternet

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Managing Your Clusters (including public, private, hybrid, edge, etc) as easily as Visiting the Internet.

Out of the Box.

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Clusternet (Cluster Internet) is an open source add-on that helps you manage thousands of millions of Kubernetes clusters as easily as visiting the Internet. No matter the clusters are running on public cloud, private cloud, hybrid cloud, or at the edge, Clusternet lets you manage/visit them all as if they were running locally. This also help eliminate the need to juggle different management tools for each cluster.

Clusternet can also help deploy and coordinate applications to multiple clusters from a single set of APIs in a hosting cluster.

Clusternet will help setup network tunnels in a configurable way, when your clusters are running in a VPC network, at the edge, or behind a firewall.

Clusternet also provides a Kubernetes-styled API, where you can continue using the Kubernetes way, such as KubeConfig, to visit a certain Managed Kubernetes cluster, or a Kubernetes service.

Clusternet is multiple platforms supported now, including linux/amd64, linux/arm64, linux/ppc64le, linux/s390x , linux/386 and linux/arm;

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• Architecture
• Concepts
• Contributing & Developing
• Getting Started
  • Installing Clusternet
  • Checking Cluster Registration
  • Visiting Managed Clusters With RBAC
  • How to Interact with Clusternet
  • Deploying Applications to Multiple Clusters

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Architecture

Clusternet is light-weighted that consists of two components, clusternet-agent and clusternet-hub.

clusternet-agent is responsible for

• auto-registering current cluster to a parent cluster as a child cluster, which is also been called ManagedCluster;
• reporting heartbeats of current cluster, including Kubernetes version, running platform, healthz/readyz/livez status, etc;
• setting up a websocket connection that provides full-duplex communication channels over a single TCP connection to parent cluster;

clusternet-hub is responsible for

• approving cluster registration requests and creating dedicated resources, such as namespaces, serviceaccounts and RBAC rules, for each child cluster;
• serving as an aggregated apiserver (AA), which is used to serve as a websocket server that maintain multiple active websocket connections from child clusters;
• providing Kubernstes-styled API to redirect/proxy/upgrade requests to each child cluster;
• coordinating and deploying applications to multiple clusters from a single set of APIs;

📌 📌 Note:

Since clusternet-hub is running as an AA, please make sure that parent apiserver could visit the clusternet-hub service.

Concepts

For every Kubernetes cluster that wants to be managed, we call it child cluster. The cluster where child clusters are registerring to, we call it parent cluster.

clusternet-agent runs in child cluster, while clusternet-hub runs in parent cluster.

• ClusterRegistrationRequest is an object that clusternet-agent creates in parent cluster for child cluster registration.
• ManagedCluster is an object that clusternet-hub creates in parent cluster after approving ClusterRegistrationRequest.
• HelmChart is an object contains a helm chart configuration.
• Subscription defines the resources that subscribers want to install into clusters. For every matched cluster, a corresponding Base object will be created in its dedicated namespace.
• Clusternet provides a two-stage priority based override strategy. Localization and Globalization will define the overrides with priority, where lower numbers are considered lower priority. Localization is namespace-scoped resource, while Globalization is cluster-scoped. Refer to Deploying Applications to Multiple Clusters on how to use these.
• Base objects will be rendered to Description objects with Globalization and Localization settings applied. Description is the final resources to be deployed into target child clusters.

Contributing & Developing

If you want to get participated and become a contributor to Clusternet, please don't hesitate to refer to our CONTRIBUTING document for details.

A developer guide is ready to help you

• build binaries for all platforms, such as darwin/amd64, linux/amd64, linux/arm64, etc;
• build docker images for multiple platforms, such as linux/amd64, linux/arm64, etc;

Getting Started

Installing Clusternet

You can try below ways to

• install Clusternet with Helm
• install Clusternet the Hard Way

Checking Cluster Registration

After clusternet-hub is successfully installed. You can try to install clusternet-agent to any Kubernetes clusters you want to manage.

Please follow this guide to check cluster registrations.

Visiting Managed Clusters With RBAC

✅ Clusternet supports visiting all your managed clusters with RBAC directly from parent cluster.

Please follow this guide to visit your managed clusters.

How to Interact with Clusternet

Clusternet has provided two ways to help interact with Clusternet.

• kubectl plugin kubectl-clusternet
• use client-go to interact with Clusternet

Deploying Applications to Multiple Clusters

Clusternet supports deploying applications to multiple clusters from a single set of APIs in a hosting cluster.

Please follow this guide to deploy your applications to multiple clusters.