kubectl (Kubernetes CLI) plugin which is like kubectl run
with rsync
.
It creates temporary Pod and synchronises your local files to the desired container and executes any command.
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.
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.
kubectl cp
- Does full file copying, which is slow if a lot of files- NFS - requires a lot of extra installation and configuration
- telepresence - Executes locally and tunnels traffic from Kubernetes
- docker-sync - Only for Docker
kubectl warp
is basically just combination of, simplified and modified version of kubectl run
, sshd-rsync
container and kubectl port-forward
to access the container.
First the warp
generates temporary SSH key pair and and starts a temporary Pod with desired image and sshd-rsync
container with the temporary public SSH public key as authorized key.
The sshd-rsync
is just container with sshd
daemon running in port 22 and rsync
binary installed so the local rsync
can sync the files to the shared volume over the SSH.
The Pod have the sshd-rsync
container defined twice, as init-container to make the initial sync before the actual container to start, and as a sidecar for the actual container to keep the files in-sync. The init-container waits one rsync
execution and completes after succesfully so the actual containers can start.
To sync the files with rsync
over the SSH, warp
opens port forwarding from random local port to the Pod port 22, what the sshd-rsync
init- and sidecar-container listen.
At first, the Pod is in init state, and only the sshd-rsync
is running and waiting for single sync execution. When the initial sync is done, the container completes succesfully so the Pod starts the actual containers.
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.
When the initial sync is done, the actual container start with sshd-rsync
as a sidecar. The warp
command continuously run rsync
command locally to update the files in the Pod.
brew install rsync ernoaapa/kubectl-plugins/warp
- Install rsync with your preferred package manager
- Download
kubectl-warp
binary from releases - Add it to your
PATH
When the plugin binary is found from PATH
you can just execute it through kubectl
CLI
kubectl warp --help
# 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
Sometimes some directories are too unnecessary to sync so you can speed up the initial sync with
--exclude
and --include
flags, those gets passed to the rsync
command, for more info see rsync manual
# 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
There's some examples with different languages in examples directory
- Golang v1.11
- Go mod enabled
go run ./main.go --image alpine -- ls -la
# Syncs your local files to Kubernetes and list the files
go install .
# Now you can use `kubectl`
kubectl warp --help