update docker image

Updating a Docker image is an essential skill when working with Docker, saving time and effort by allowing for incremental changes rather than creating a new image each time.

Introduction

This is a simple step-by-step guide to updating a Docker image.

Getting Started

You’ll first need to have Docker running on your PC. If you don’t have Docker installed yet, you can download it from the official website.

Step 1: Pull the Docker Image

The first step to updating a Docker image is to pull the existing image. Use the following command:

docker pull [image name]

Replace [image name] with the name of the Docker image you want to update.

Step 2: Run a Docker Container

After pulling the Docker image, it’s time to run a Docker container. Use the following command:

docker run -it [image name] /bin/bash

This command starts a new Docker container and opens an interactive session.

Step 3: Make Changes

Now you are inside the Docker container. You can make the desired changes in this environment.

Step 4: Exit the Docker Container

Once all the changes are made, exit the Docker container by typing exit and hitting Enter.

Step 5: Commit the Changes

After exiting the Docker container, run the following command to save the changes:

docker commit [container id] [new image name] 

You get the [container id] using the docker ps -a command which lists all containers. Replace [new image name] with the name you desire for the updated image.

Step 6: Verify Changes

Finally, verify that the changes have been saved correctly by running the following command:

docker images

The updated Docker image should be listed

Updating a Docker image can seem complicated initially, but these simple steps make it a straightforward process and a great way to save time when working with Docker.