10 — Push image to Docker Hub

Category: Registry · Priority: High

Tag correctly: docker tag myapp yourusername/myapp:v1.0.0. Learn semantic versioning. Also try the latest tag.

🎯 What is this task?

A Docker image is built on your computer, but to share it or deploy it to the cloud, you need to push it to a registry — a storage service for Docker images. Docker Hub is the most popular free option (like GitHub, but for Docker images).

🤖 AI Prompt

"Explain step by step how to tag a local Docker image and push it to Docker Hub. The local image is called my-docker-app. My Docker Hub username is yourusername. Show the exact commands for: logging in, tagging with a version and latest, pushing, and then pulling it back to verify."

📋 Step-by-step

Step 1 — Create a Docker Hub account

Go to https://hub.docker.com and sign up for a free account. Remember your username.

Step 2 — Log in to Docker Hub from terminal

docker login

Enter your Docker Hub username and password when prompted. You should see Login Succeeded.

Step 3 — Tag your image

Docker images need to be tagged with your username before pushing. Replace yourusername with your actual Docker Hub username:

docker tag my-docker-app:v5 yourusername/my-docker-app:v1.0.0
docker tag my-docker-app:v5 yourusername/my-docker-app:latest

You now have two tags for the same image — a specific version and latest.

Step 4 — Push to Docker Hub

docker push yourusername/my-docker-app:v1.0.0
docker push yourusername/my-docker-app:latest

You'll see progress bars as each layer uploads. After it completes, go to https://hub.docker.com/r/yourusername/my-docker-app in your browser — your image should appear there.

Step 5 — Verify by pulling it back

Delete your local copy and pull it from Docker Hub to confirm it works:

docker rmi yourusername/my-docker-app:latest
docker pull yourusername/my-docker-app:latest
docker run -p 3000:3000 yourusername/my-docker-app:latest

Open http://localhost:3000 — it should work, now running from the cloud-pulled image.

💡 Good habits for image tagging

• Use semantic versioning: v1.0.0, v1.1.0, v2.0.0
• Always also tag as latest for convenience
• Never push images with secrets or credentials baked in

✅ Done when

• Docker Hub account created
• docker login succeeds
• Image pushed to yourusername/my-docker-app:v1.0.0 and latest
• Image visible on hub.docker.com
• docker pull yourusername/my-docker-app:latest works from terminal