karmada Documentation

1. Project Overview & Quickstart (karmada-io/karmada) Copy Chapter

File: README.md Copy Chapter

Karmada

Karmada: Open, Multi-Cloud, Multi-Cluster Kubernetes Orchestration Copy Chapter

Karmada (Kubernetes Armada) is a Kubernetes management system that enables you to run your cloud-native applications across multiple Kubernetes clusters and clouds, with no changes to your applications. By speaking Kubernetes-native APIs and providing advanced scheduling capabilities, Karmada enables truly open, multi-cloud Kubernetes.

Karmada aims to provide turnkey automation for multi-cluster application management in multi-cloud and hybrid cloud scenarios,
with key features such as centralized multi-cloud management, high availability, failure recovery, and traffic scheduling.

Karmada is an incubation project of the Cloud Native Computing Foundation (CNCF).

Why Karmada: Copy Chapter

• K8s Native API Compatible

  • Zero change upgrade, from single-cluster to multi-cluster
  • Seamless integration of existing K8s tool chain

• Out of the Box

  • Built-in policy sets for scenarios, including: Active-active, Remote DR, Geo Redundant, etc.
  • Cross-cluster applications auto-scaling, failover and load-balancing on multi-cluster.

• Avoid Vendor Lock-in

  • Integration with mainstream cloud providers
  • Automatic allocation, migration across clusters
  • Not tied to proprietary vendor orchestration

• Centralized Management

  • Location agnostic cluster management
  • Support clusters in Public cloud, on-prem or edge

• Fruitful Multi-Cluster Scheduling Policies

  • Cluster Affinity, Multi Cluster Splitting/Rebalancing
  • Multi-Dimension HA: Region/AZ/Cluster/Provider

• Open and Neutral

  • Jointly initiated by Internet, finance, manufacturing, teleco, cloud providers, etc.
  • Target for open governance with CNCF

Notice: This project is developed in continuation of Kubernetes Federation v1 and v2. Some basic concepts are inherited from these two versions.

Architecture Copy Chapter

The Karmada Control Plane consists of the following components:

• Karmada API Server
• Karmada Controller Manager
• Karmada Scheduler

ETCD stores the Karmada API objects, the API Server is the REST endpoint all other components talk to, and the Karmada Controller Manager performs operations based on the API objects you create through the API server.

The Karmada Controller Manager runs the various controllers, the controllers watch Karmada objects and then talk to the underlying clusters' API servers to create regular Kubernetes resources.

1. Cluster Controller: attach Kubernetes clusters to Karmada for managing the lifecycle of the clusters by creating cluster objects.
2. Policy Controller: the controller watches PropagationPolicy objects. When the PropagationPolicy object is added, it selects a group of resources matching the resourceSelector and creates ResourceBinding with each single resource object.
3. Binding Controller: the controller watches ResourceBinding object and create Work object corresponding to each cluster with a single resource manifest.
4. Execution Controller: the controller watches Work objects. When Work objects are created, it will distribute the resources to member clusters.

Concepts Copy Chapter

Resource template: Karmada uses Kubernetes Native API definition for federated resource template, to make it easy to integrate with existing tools that already adopt on Kubernetes

Propagation Policy: Karmada offers a standalone Propagation(placement) Policy API to define multi-cluster scheduling and spreading requirements.

• Support 1:n mapping of Policy: workload, users don't need to indicate scheduling constraints every time creating federated applications.
• With default policies, users can just interact with K8s API

Override Policy: Karmada provides standalone Override Policy API for specializing cluster relevant configuration automation. E.g.:

• Override image prefix according to member cluster region
• Override StorageClass according to cloud provider

The following diagram shows how Karmada resources are involved when propagating resources to member clusters.

Quick Start Copy Chapter

This guide will cover:

• Install karmada control plane components in a Kubernetes cluster which is known as host cluster.
• Join a member cluster to karmada control plane.
• Propagate an application by using karmada.

Prerequisites Copy Section

• Go version follows go.mod
• kubectl version v1.19+
• kind version v0.14.0+

Install the Karmada control plane Copy Section

1. Clone this repo to your machine:

git clone https://github.com/karmada-io/karmada

2. Change to the karmada directory:

cd karmada

3. Deploy and run Karmada control plane:

run the following script:

hack/local-up-karmada.sh

This script will do the following tasks for you:

• Start a Kubernetes cluster to run the Karmada control plane, aka. the host cluster.
• Build Karmada control plane components based on a current codebase.
• Deploy Karmada control plane components on the host cluster.
• Create member clusters and join Karmada.

If everything goes well, at the end of the script output, you will see similar messages as follows:

Local Karmada is running.

To start using your Karmada environment, run:
  export KUBECONFIG="$HOME/.kube/karmada.config"
Please use 'kubectl config use-context karmada-host/karmada-apiserver' to switch the host and control plane cluster.

To manage your member clusters, run:
  export KUBECONFIG="$HOME/.kube/members.config"
Please use 'kubectl config use-context member1/member2/member3' to switch to the different member cluster.

There are two contexts in Karmada:

• karmada-apiserver kubectl config use-context karmada-apiserver
• karmada-host kubectl config use-context karmada-host

The karmada-apiserver is the main kubeconfig to be used when interacting with the Karmada control plane, while karmada-host is only used for debugging Karmada installation with the host cluster. You can check all clusters at any time by running: kubectl config view. To switch cluster contexts, run kubectl config use-context [CONTEXT_NAME]

Demo Copy Section

Propagate application Copy Section

In the following steps, we are going to propagate a deployment by Karmada.

1. Create nginx deployment in Karmada.

First, create a deployment named nginx:

kubectl create -f samples/nginx/deployment.yaml

2. Create PropagationPolicy that will propagate nginx to member cluster

Then, we need to create a policy to propagate the deployment to our member cluster.

kubectl create -f samples/nginx/propagationpolicy.yaml

3. Check the deployment status from Karmada

You can check deployment status from Karmada, don't need to access member cluster:

$ kubectl get deployment
NAME    READY   UP-TO-DATE   AVAILABLE   AGE
nginx   2/2     2            2           20s

Kubernetes compatibility Copy Chapter

Karmada is compatible with a wide range of Kubernetes versions. For detailed compatibility instructions,
please refer to the Kubernetes Compatibility.

The following table shows the compatibility test results against the latest 10 Kubernetes versions:

Key:

• ✓ Karmada and the Kubernetes version are exactly compatible.
• + Karmada has features or API objects that may not be present in the Kubernetes version.
• - The Kubernetes version has features or API objects that Karmada can't use.

Meeting Copy Chapter

Regular Community Meeting:

• Tuesday at 14:30 UTC+8 (Chinese)(biweekly). Convert to your timezone.
• Tuesday at 15:00 UTC+0 (English)(biweekly). Convert to your timezone.

Resources:

• Meeting Notes and Agenda
• Meeting Calendar | Subscribe
• Meeting Link

Contact Copy Chapter

If you have questions, feel free to reach out to us in the following ways:

• mailing list
• slack | Join
• twitter

References Copy Chapter

• To learn about companies and organizations using Karmada in production, please visit Adopters page.
• For commercial support, professional services, and consulting, please visit Partners page.
• For talks and presentations about Karmada, please visit Community Talks.
• For blogs and articles, please visit website.

Contributing Copy Chapter

If you're interested in being a contributor and want to get involved in
developing the Karmada code, please see CONTRIBUTING for
details on submitting patches and the contribution workflow.

License Copy Chapter

Karmada is under the Apache 2.0 license. See the LICENSE file for details.

File: docs/README.md Copy Chapter

Karmada documentation is all hosted on karmada-io/website.

2. Official Technical Reference & Guides (karmada-io/website) Copy Chapter

Karmada Docs & Website

This repo contains the source code of Karmada website and all of the docs for Karmada.
It's built by Docusaurus, a modern static website generator.

• Karmada website
• Karmada docs
• Karmada Blog

Welcome to join us and you are more than appreciated to contribute!

Release Branch Versioning Copy Chapter

Each release branch maintains documentation for the 6 most recent versions of Karmada. For example, the release-1.14 branch maintains documentation for Karmada versions v1.9 through v1.14. This versioning strategy ensures that users can access documentation for recent versions while keeping the repository manageable.

When a new minor version is released, the documentation for the oldest version is removed from maintenance, and the branch is updated to include documentation for the new version.

Website Preview Copy Chapter

If you only update the docs, you do not need to preview the website locally.
We will create a preview link for you when you submit a pull request (PR). In an open PR,
you can find the preview link in the comment of the PR.
Check Open PRs List.

Run with Node.js Copy Chapter

If you have the Node.js environment, you can run the website locally.

# Clone the repo, or your own fork
git clone https://github.com/<YOUR_GITHUB_USERNAME>/karmada-website.git

# Install dependencies
cd karmada-website
npm install

# Start the site
yarn run start

Run with Docker Copy Chapter

If you do not want to install the Node.js environment, you can consider using Docker instead.

make serve

With just one command, you can run it locally and then access http://localhost:3000 to preview the website.

Local Development Copy Chapter

If you want to contribute to the website, firstly, it is essential to learn some basic knowledge of Docusaurus.

Run the development server Copy Section

To start a local development server, please run:

yarn run start

This command starts a local development server and opens a browser window at http://localhost:3000.
Most changes are automatically reflected live without the need to restart the server.

Build Copy Section

yarn run build

This command generates static content into the build directory and can be served using any static contents hosting service.

Deployment Copy Section

GIT_USER=<Your GitHub username> USE_SSH=true yarn deploy

If you are using GitHub pages for hosting, this command is a convenient way to build the website and push to the gh-pages branch.