Using skaffold for continuous development on local/remote K8s

matharoo

Categories

  • devops

Tags

  • devops
  • kubernetes
  • skaffold

skaffold

Skaffold is a great continuous development tool that helps test build, push and deploying the application. Especially for developers it easily allow app to be built and deployed to their local cluster or even remote clusters allowing them to easily detect any anomalies that their changes may cause to the building or deployment process.

Components involved:

  • skaffold
  • minikube / kind cluster
  • app with Dockerfile and your kubernetes manifests

In this quick tutorial we will be continuing the setup on our mynode-app: https://github.com/matharoo/mynode-app.

Adding skaffold to your app

First we have to ensure that our project has working Dockerfile and k8s directory with kubernetes manifests like deployments and services at least.

Once you have installed skaffold client on your machine, all we need to do is run skaffold init in our projects root dir which generates a skaffold yaml and automatically detect the Dockerfile and K8s manifests in the project. It makes it easy for developers to deploy to different namespaces in your local cluster.

Running the app

Now we can just run either of the following commands to deploy to the current selected cluster-context:

  • skaffold dev -n nodejs if we want to build and deploy the new changes continuously and watch for any file changes inside our project root dir. And after we exit skaffold it removes the deployments.
skaffold-dev
running skaffold in dev mode continuously watches and rebuilds and redeploys
  • skaffold run -n nodejs just create the image once if doesn’t exist and deploy it and test.
skaffold-run
it builds and deploy to k8s which can then be deleted with `skaffold delete -n nodejs`
  • skaffold deploy -n nodejs to just deploy the pre built image.

These commands generate a new docker image for the project and then automatically deploys it to the cluster according the deployment manifest.

To finally access the app on browser we can use the kubectl port forward method like:

kubectl port-forward deployment/mynode-app 3000:3000 -n development
Output:
Forwarding from 127.0.0.1:3000 -> 3000
Forwarding from [::1]:3000 -> 3000

Now app can be tested at : http://localhost:3000/

So skaffold can simplify the life of developers who are entering in the realm of developing and testing their app on kubernetes without even have to worry about learning and running the kubectl commands.

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