Pushing Docker images to Docker Hub

Keeping your images in a Docker Hub repo will make your life easier

Pushing Docker images to Docker Hub

This post assumes you already have an account on Docker Hub. If you don’t, sign up for free before going any further.

Once you have a Docker Hub account, log in and create the repository where you want to store the image. You can do that by clicking the Create Repository button.

Building the image

To push an image to Docker Hub, you will need to have it on your machine. An image can be built from instructions in a Dockerfile or using Docker Compose. Personally, I like to create images from Dockerfiles, where I define my desired OS with all softwares and packages I need. Assuming you alrady have a Dockerfile, cd to the directory where the Dockerfile is and run:

docker build -t username/reponame .

Here, username and reponame are your Docker Hub’s user name and the name of the repository where you want to store the image.

Pushing to Docker Hub

To push your image, you must be logged in. To log in, run:

docker login

You will be asked to type your user name and password, and then you’re all set. Finally, push the image with:

docker push username/reponame:tag

Note that the :tag is not mandatory. If you omit it, a tag latest will be automatically assigned. You would want to assign a custom tag if you’re pushing a specific version of your image. For example, suppose I want to push the version 2.0 of an image to my soyfungigcn repo. To do that, I would run:

docker push almeidasilvaf/soyfungigcn:2.0

And that’s it! In the future, if you want to use that same image on a different machine, all you need to do is run:

docker pull username/reponame

This will download the latest version of the image to your machine. You can also specify a specific version to download by setting a :tag after the repository name.