Hello World Example

This tutorial will demonstrate how to get started with Rancher Desktop by pushing an app to a local Kubernetes cluster.

Rancher Desktop works with two container engines, containerd and Moby, the open-sourced components of the Docker ecosystem. For nerdctl, use the containerd runtime. For docker, use the dockerd(moby) runtime.

Example#1 - Build Image & Run Container

Create a folder

  1. mkdir hello-world
  2. cd hello-world

Create a blank Dockerfile

On Windows, Create a blank file named Dockerfile

On Linux, You can use below command to create a blank Dockerfile

  1. vi Dockerfile

Populate the Dockerfile with the command below

  1. FROM alpine  
  2. CMD ["echo", "Hello World!!"]

Build and run the image for verification purposes

  • nerdctl
  • docker
  1. nerdctl build --tag helloworld:v1.0 .
  2. nerdctl images | grep helloworld
  3. nerdctl run --rm helloworld:v1.0
  4. # Remove the image
  5. nerdctl rmi helloworld:v1.0
  1. docker build --tag helloworld:v1.0 .
  2. docker images | grep helloworld
  3. docker run --rm helloworld:v1.0
  4. # Remove the image
  5. docker rmi helloworld:v1.0

Example#2 - Build Image & Deploy Container to Kubernetes

Make sure that you switch the Container Runtime setting in the Kubernetes Settings panel to either dockerd or containerd as needed.

Create a folder and add a sample index.html file as follows

  1. mkdir nginx
  2. cd nginx
  3. echo "<h1>Hello World from NGINX!!</h1>" > index.html

Create a blank Dockerfile

On Windows, Create a blank file named Dockerfile

On Linux, You can use below command to create a blank Dockerfile

  1. vi Dockerfile

Populate the Dockerfile with the command below

  1. FROM nginx:alpine
  2. COPY . /usr/share/nginx/html

Build image from code locally

⚠️ Note: Please note that you need to pass the flag --namespace k8s.io to the nerdctl build command, so that nerdctl builds the image and then makes it available in the k8s.io namespace.

  • nerdctl
  • docker
  1. nerdctl --namespace k8s.io build --tag nginx-helloworld:latest .
  2. nerdctl --namespace k8s.io images | grep nginx-helloworld
  1. docker build --tag nginx-helloworld:latest .
  2. docker images | grep nginx-helloworld

Deploy to Kubernetes

Run below command to create and run a pod using the image built in the previous step.

⚠️ Note: Please note that you need to pass the flag --image-pull-policy=Never to use a local image with :latest tag, as :latest tag will always try to pull the images from a remote repository.

  1. kubectl run hello-world --image=nginx-helloworld:latest --image-pull-policy=Never --port=80
  2. kubectl port-forward pods/hello-world 8080:80

Point your web browser to localhost:8080, and you will see the message Hello World from NGINX!!. If you prefer to stay on the command line, use curl localhost:8080.

Delete the pod and the image

  • nerdctl
  • docker
  1. kubectl delete pod hello-world
  2. # Remove the image
  3. nerdctl --namespace k8s.io rmi nginx-helloworld:latest
  1. kubectl delete pod hello-world 
  2. # Remove the image
  3. docker rmi nginx-helloworld:latest