k3s in docker

k3s is the lightweight Kubernetes distribution by Rancher: rancher/k3s

k3d creates containerized k3s clusters. This means, that you can spin up a multi-node k3s cluster on a single machine using docker.

Learning

• Website with documentation: k3d.io
• Rancher Meetup - May 2020 - Simplifying Your Cloud-Native Development Workflow With K3s, K3c and K3d (YouTube)k3d demo repository: iwilltry42/k3d-demo

Requirements

• docker

Get

You have several options there:

• use the install script to grab the latest release:
• wget: wget -q -O - https://raw.githubusercontent.com/rancher/k3d/main/install.sh | bash
• curl: curl -s https://raw.githubusercontent.com/rancher/k3d/main/install.sh | bash
• use the install script to grab a specific release (via TAG environment variable):
• wget: wget -q -O - https://raw.githubusercontent.com/rancher/k3d/main/install.sh | TAG=v3.0.0 bash
• curl: curl -s https://raw.githubusercontent.com/rancher/k3d/main/install.sh | TAG=v3.0.0 bash
• use Homebrew: brew install k3d (Homebrew is available for MacOS and Linux)
• Formula can be found in homebrew/homebrew-core and is mirrored to homebrew/linuxbrew-core
• install via AUR package rancher-k3d-bin: yay -S rancher-k3d-bin
• grab a release from the release tab and install it yourself.
• install via go: go install github.com/rancher/k3d (Note: this will give you unreleased/bleeding-edge changes)

or…

Build

1. Clone this repo, e.g. via git clone git@github.com:rancher/k3d.git or go get github.com/rancher/k3d/v3@main
2. Inside the repo run

• ‘make install-tools’ to make sure required go packages are installed

1. Inside the repo run one of the following commands

• make build to build for your current system
• go install to install it to your GOPATH (Note: this will give you unreleased/bleeding-edge changes)
• make build-cross to build for all systems

Usage

Check out what you can do via k3d help or check the docs @ k3d.io

Example Workflow: Create a new cluster and use it with kubectl

1. k3d cluster create CLUSTER_NAME to create a new single-node cluster (= 1 container running k3s + 1 loadbalancer container)
2. k3d kubeconfig merge CLUSTER_NAME --switch-context to update your default kubeconfig and switch the current-context to the new one
3. execute some commands like kubectl get pods --all-namespaces
4. k3d cluster delete CLUSTER_NAME to delete the default cluster

#kubernetes #docker #devops