Containers - Image Versions

Prerequisites

• Docker

Assignment

• Lets start by creating a container for running a website in a container using containerd and nerdctl.

1. Create an index.html file for the website.

    mkdir mywebsite
   

2. Add content to the index.html file

    echo "<h1>Welcome to Containers!!! Version 1</h1>" > ./mywebsite/index.html   
   

3. Verify the content of the index.html file

    cat ./mywebsite/index.html
   

4. Create a Dockerfile to create an container

    touch  ./mywebsite/Dockerfile
   

5. Add the below steps in the Dockerfile

    cat <<EOF > ./mywebsite/Dockerfile
    # Use a lightweight web server base image
    FROM nginx:alpine
   
    # Copy the HTML file to the web server's root directory
    COPY index.html /usr/share/nginx/html/index.html
   
    # Expose the web server's port
    EXPOSE 80
    EOF
   

6. Build an image with nerdctl using the Dockerfile

    docker build -t mywebsite:v1 ./mywebsite
   

7. Verify if the images has been created

    docker images
   

8. Run the Container using the image created in the previous step

    docker run -d -p 8081:80 --name container-demo mywebsite:v1
   

9. Verify if the container is up and running

    docker ps
   

10. Browse the Website using the port 8080

    /mnt/c/Program\ Files/Google/Chrome/Application/chrome.exe http://localhost:8080/
    

11. Update the index.html with some changes

    echo "<h1>Welcome to Containers!</h1> Version 2" > ./mywebsite/index.html   
    

12. Build a new image which will include the changes

    docker build -t mywebsite:v2 ./mywebsite
    

13. Run the container with the new image named v2

    docker run -d -p 8082:80 --name container-demo mywebsite:v2
    

14. Browse the website and confirm that the changes are reflected.

    /mnt/c/Program\ Files/Google/Chrome/Application/chrome.exe http://localhost:8082/