create docker image

Docker is a wonderful tool that helps developers package their applications into containers. This makes them portable and ready for deployment on any machine.

Now let’s dive into “how you can create a Docker image yourself”.

Step 1: Install Docker

First, you need Docker on your computer. If Docker is playing hide and seek, head over to the official Docker website. There you’ll find detailed instructions on how to install it on your specific operating system: whether you’re team Windows, MacOS, or Linux.

Step 2: Create a Dockerfile

Now, it’s all about the Dockerfile. This little fellow holds the instructions needed to create a Docker image. To get it started, create a new folder on your computer and name it something like mydocker. Inside, create a new text file and rename it as Dockerfile, no extensions.

Step 3: Define Base Image

A Dockerfile begins by defining a base image. This image acts as a starting point for your new image.

It could be a simple Linux OS, a Windows server, or even another Dockerfile.

For our tutorial, we’ll use the simplest base image, Alpine Linux.

Write FROM alpine This tells Docker we want to start with a basic Alpine Linux image.

Step 4: Run Commands

The next step is to tell Docker what to do with your image.

For example, you might want Docker to install a web server or some software. You do this by using a RUN instruction.

For example, RUN apk add --update nodejs nodejs-npm This command installs Node.js and Npm on our Alpine Linux image.

Step 5: Finish up your Dockerfile

In addition to the FROM and the RUN command, there’s another command you need to add to your Dockerfile: CMD. This command specifies what should be run when a container is started from your image. For our tutorial, you can use CMD ["node"].

Your complete Dockerfile should now look something like this:

FROM alpine
RUN apk add --update nodejs nodejs-npm
CMD ["node"]

Step 6: Build your Docker Image

Save your Dockerfile and open a terminal at the location of your Dockerfile. To build the Docker image, run the command: docker build -t mynode . The -t option is used to tag the image with a name mynode, and the . tells Docker to look for a Dockerfile in the current directory.

And voila! You have just created a Docker image.

Step 7: Verify

Want to see the fruits of your labor? Heck yeah, you do! Just type docker images in your terminal and hit enter. You’d see your image mynode proudly listed there.

That’s it, folks! You just successfully built your very first Docker image. Now you can distribute your software in a way that’s not only convenient but also reliable.