Documentation: Pushing and Pulling a Docker Image to Docker Hub

This guide walks you through the steps to push a custom WordPress image to Docker Hub and verify it by pulling it back. It’s designed to be beginner-friendly!

Step 1: Create a Docker Hub Account

1. Sign Up for Docker Hub:
   • Go to the Docker Hub website.
   • Click on Sign Up.
   • Fill in the required details to create your account.

Step 2: Prepare Your Docker Image

1. Tag the Image:
   To push an image to Docker Hub, it needs to be tagged correctly with the format:

   [DockerHubUsername]/[RepositoryName]:[Tag]

Example:

   docker tag [IMAGE_ID] your-username/wordpress:latest

In my case, I tagged my WordPress image:

   docker tag 2f3572d5cd72 your-username/wordpress:latest

• 2f3572d5cd72 is the image ID of my WordPress container.
• your-username/wordpress:latest is the name and tag for the image in my Docker Hub repository.

Step 3: Push the Image to Docker Hub

1. Login to Docker Hub:
   Before pushing an image, make sure you’re logged in using:

   docker login

1. Push the Tagged Image:
   Use the docker push command to upload the image to Docker Hub:

   docker push your-username/wordpress:latest

• The output showed Docker uploading layers of my image to the repository. If some layers were already present in the official WordPress image, Docker reused them.

1. Successful Push Confirmation:
   The output ended with:

   latest: digest: sha256:78a7f1bd075abad746e53aca7605976c2cf76796b1f868bc3adb17a98bbf0287 size: 5161

This confirmed that the image was successfully pushed.

Step 4: Verify the Image on Docker Hub

1. Check the Repository Online:
   I logged in to Docker Hub and navigated to my repository (your-username/wordpress). The image with the latest tag was listed there.

Step 5: Pull the Image to Verify

1. Pull the Image:
   To test that the image works, I pulled it from Docker Hub using:

   docker pull your-username/wordpress:latest

• This downloaded the image from Docker Hub.
• The successful pull confirmed that the image was stored correctly.

Tips & Notes

• Login to Docker Hub: Before pushing an image, make sure you’re logged in using:

  docker login

• Repository Naming: The name must include your Docker Hub username (e.g., your-username/wordpress).

That’s it! Your WordPress image is now available on Docker Hub and ready for deployment anywhere.