Install

At the end of this page, you have the jr2 CLI and a kind cluster on your computer. The next pages use them to make an Instance and run it.

Before you start

This is the first page of the tutorial. You need a computer with these tools:

• Node.js 24 or later. Node.js includes npm.
• Docker. Make sure that the Docker daemon runs.
• kind, which runs a Kubernetes cluster in Docker.
• kubectl, which speaks to the cluster.

kind makes the cluster from Docker containers. jr2 up builds an image with Docker and loads it into the kind cluster. kubectl is the tool that jr2 up, jr2 run and the other commands use to speak to the cluster.

Check Node.js

Run:

node --version

The version must be v24 or later:

v24.18.0

Your version can be different.

Install the jr2 CLI

Run:

npm i -g @jr2/cli

npm installs the jr2 command and the @jr2/orchestrator package that it uses. npm prints its progress and a summary of the packages that it added. This page does not show that output. The next step checks the install.

Check the jr2 CLI

Run:

jr2 --version

The CLI shows its version, its folder and the version of Node.js. Outside an Instance, it shows no Instance:

cli:       <version>    /tmp/jr2-dist/npm-global/lib/node_modules/@jr2/cli
instance:  none — no jr2.config.ts walking up from cwd
node:      v24.18.0

<version> is the version of jr2 that you installed, such as 0.4.1. The folder is in the global folder of your npm, so it can be different.

Make the kind cluster

Run:

kind create cluster --name jr2

kind makes a cluster with one node. It sets your current kubectl context to the new cluster:

Creating cluster "jr2" ...
…
Set kubectl context to "kind-jr2"
…

The context of the cluster is kind-jr2. jr2 up converges into the current kubectl context, so the next pages use this cluster.

Check the Kubernetes version

Run:

kubectl version

The Server Version must be v1.35 or later:

Client Version: v1.35.7
Kustomize Version: v5.7.1
Server Version: v1.36.1

Your versions can be different. If the server version is earlier than v1.35, delete the cluster with kind delete cluster --name jr2. Then install a newer kind release. Make the cluster again. jr2 up refuses an older cluster with this message, where <server version> is the Server Version of the cluster:

refusing: kind-jr2 runs Kubernetes <server version>; jr2 needs Kubernetes 1.35 or newer (every Sandbox mounts jr2's runtime as an image volume, ADR-0037). Nothing was applied.

What happened

You installed the jr2 CLI globally. It is the command that you use for each step of this tutorial. Each Instance also installs its own copy of @jr2/cli. In an Instance folder, the global jr2 gives the command to that copy. Thus the version that runs is the version that the Instance pins. The glossary calls this a Handoff.

You also made a kind cluster. jr2 needs no setup in the cluster other than Kubernetes 1.35 or later. jr2 up puts in it all that an Instance needs. Converge explains what jr2 up makes. The CLI reference gives each command and its options.

Next

Create an Instance.