kubectl (Kubernetes CLI) plugin which is like

kubectl run

rsync

It creates temporary Pod and synchronises your local files to the desired container and executes any command.

Why

Sometimes you need to develop/execute your code in Kubernetes, because access to database, insufficient resources locally, need access to some specific device, use specific architecture, etc. The full build image, push, deploy cycle is way too slow for real development.

Use cases

This can be used for example to build and run your local project in Kubernetes where's more resources, required architecture, etc. while using your prefed editor locally.

Alternatives

• kubectl cp

  - Does full file copying, which is slow if a lot of files
• NFS - requires a lot of extra installation and configuration

Other similar

• telepresence - Executes locally and tunnels traffic from Kubernetes
• docker-sync - Only for Docker

How it works

kubectl warp

kubectl run

sshd-rsync

kubectl port-forward

1. Start the Pod

First the

warp

sshd-rsync

The

sshd-rsync

sshd

rsync

rsync

sshd-rsync

rsync

2. Open tunnel

To sync the files with

rsync

warp

sshd-rsync

3. Initial sync

At first, the Pod is in init state, and only the

sshd-rsync

The initial sync is needed so that we can start the actual container with any command. E.g. if we have shell script

test.sh

and when the container start with

./test.sh

as the command, the file must be there available before the execution.

4. Continuous syncing

When the initial sync is done, the actual container start with

sshd-rsync

warp

rsync

Install

With Krew (Kubernetes plugin manager)

Install Krew, then run the following commands:

krew update
krew install warp

MacOS with Brew

brew install rsync ernoaapa/kubectl-plugins/warp

Linux / MacOS without Brew

1. Install rsync with your preferred package manager
2. Download

   kubectl-warp

   binary from releases
3. Add it to your

   PATH

Usage

When the plugin binary is found from

PATH

kubectl

shell
kubectl warp --help

Basics

# Start bash in ubuntu image. Files in current directory will be synced to the container
kubectl warp -i -t --image ubuntu testing -- /bin/bash

Start nodejs project in node container
cd examples/nodejs
kubectl warp -i -t --image node testing-node -- npm run watch

Exclude / Include

Sometimes some directories are too unnecessary to sync so you can speed up the initial sync with

--exclude

--include

rsync

Do not sync local node_modules, because we fetch dependencies in the container as first command

cd examples/nodejs kubectl warp -i -t --image node testing-node --exclude="node_modules/***" -- npm install && npm run watch ```

Examples

There's some examples with different languages in examples directory

Development

Prerequisites

• Golang v1.11
• Go mod enabled

Build and run locally

go run ./main.go --image alpine -- ls -la

Syncs your local files to Kubernetes and list the files

Build and install locally

go install .

Now you can use kubectl
kubectl warp --help