Docker Docker Registry and Repository Docker Hub Public vs Private Repositories Docker Login docker push docker tag

1. Core Command / Concept

Docker Hub allows you to store and share Docker images. docker login.

2. Step‑by‑Step

1. Check if you have a Docker Hub account: docker login
2. Enter your Docker Hub username and password when prompted.
3. Verify login success: docker login -u <username> -p <password>
4. Create a new public repository: docker tag <image_name> <username>/<image_name>
5. Push the image to Docker Hub: docker push <username>/<image_name>
6. Clean up by removing the local image: docker rmi <image_name>
7. ⚠️ Delete all stopped containers: docker container prune

3. Real Commands with Examples

Example 1: Login and Push

• Purpose: Push a Docker image to a public repository.
• Command: docker login -u <username> -p <password> && docker tag <image_name> <username>/<image_name> && docker push <username>/<image_name>
• Brief explanation of flags: -u specifies the username, -p specifies the password.

Example 2: Private Repository

• Purpose: Push a Docker image to a private repository.
• Command: docker login -u <username> -p <password> && docker tag <image_name> <username>/<image_name> && docker push <username>/<image_name>
• Brief explanation of flags: Same as Example 1.

Example 3: Tagging

• Purpose: Tag a Docker image with a new name.
• Command: docker tag <image_name> <username>/<image_name>
• Brief explanation of flags: None.

4. Common Errors

Error 1: Login Failure

• Error message or symptom: "Login failed"
• Why it happens: Incorrect username or password.
• One-line fix: docker login -u <username> -p <password>

Error 2: Image Not Found

• Error message or symptom: "image not found"
• Why it happens: Image does not exist locally.
• One-line fix: docker pull <image_name>

Error 3: Push Failure

• Error message or symptom: "push failed"
• Why it happens: Image not tagged correctly.
• One-line fix: docker tag <image_name> <username>/<image_name>

5. Quick Checks

Scenario 1: Login Status

• Situation: You want to check if you are logged in.
• Command to run: docker login
• What a correct response looks like: "Login Succeeded"

Scenario 2: Image List

• Situation: You want to list all Docker images.
• Command to run: docker images
• What a correct response looks like: A list of images with their tags.

Scenario 3: Push Status

• Situation: You want to check the push status.
• Command to run: docker push <username>/<image_name>
• What a correct response looks like: "Push successful"

6. Last‑Minute Reference

• Docker Hub URL: https://hub.docker.com
• Docker Hub username: Your Docker Hub username
• Docker Hub password: Your Docker Hub password
• Image name: The name of your Docker image
• Username: Your Docker Hub username
• Password: Your Docker Hub password
• ⚠️ Docker Hub rate limits: 100 requests per hour
• ⚠️ Docker Hub image size limits: 1 GB
• ⚠️ Docker Hub repository limits: 100 repositories
• ⚠️ Docker Hub team limits: 10 teams