Tagging and pushing Docker images is a fundamental part of modern containerized development and deployment workflows. Once you’ve built a Docker image, essentially a packaged snapshot of your application and its environment, you’ll often want to share it with others or deploy it across different systems. That’s where tagging and pushing come in.
Tagging is the process of assigning a human-readable identifier to an image, typically in the format repository:tag (e.g., myapp:1.0). This helps distinguish between different versions or configurations of the same application. Tags like latest, dev, or semantic versions (v1.2.3) are commonly used to track changes and manage deployments.
Once tagged, the image can be pushed to a Docker registry, a centralized location where images are stored and accessed. This could be a public registry like Docker Hub or a private one hosted internally or on the cloud. Pushing an image makes it accessible to other developers, CI/CD pipelines, or production environments.
Together, tagging and pushing enable consistent, repeatable deployments and simplify collaboration across teams. They’re essential practices for anyone working with Docker in real-world projects, especially when integrating with version control and automated pipelines.
PROCESS TO TAG AND PUSH A DOCKER IMAGE TO REGISTRY
| STEP | COMMAND | DESCRIPTION |
| BUILD THE IMAGE | docker build -t myapp . | Builds an image from a Dockerfile in the current directory. |
| TAG THE IMAGE | docker tag myapp username/myapp:1.0 | Tags the image with a name and version for the registry. |
| LOG IN TO REGISTRY | docker login | Authenticates you with Docker Hub or another registry. |
| PUSH IMAGE | docker push username/myapp:1.0 | Uploads the tagged image to the registry. |
| PUSH ALL TAGS (OPTIONAL) | docker push --all-tags username/myapp | Pushes all tags of the image to the registry. |
| VERIFY ON REGISTRY | Visit Docker Hub or your private registry UI | Confirms the image is available remotely. |
EXAMPLE CODE-
docker build -t myapp .
docker tag myapp USER1/myapp:1.0
docker login
docker push USER1/myapp:1.0
IMAGE VERSIONING & ROLLBACK
What Is Image Versioning?
Image versioning is the process of tagging Docker images with unique identifiers that represent specific states of your application. These tags can be:
- Semantic versions (e.g.,
v1.2.3) - Git commit hashes (e.g.,
abc123) - Timestamps (e.g.,
2025-06-30) - Environment-specific tags (e.g.,
staging,production)
This allows teams to track changes, ensure consistency across environments, and avoid the pitfalls of mutable tags like latest, which can silently change over time.
What Is a Rollback?
A rollback is the act of reverting to a previous, known-good version of an image when a newer deployment causes issues. With Docker, this is as simple as redeploying an older image tag:
docker run myapp:v1.2.0
Because Docker images are immutable, rollbacks are fast, reliable, and don’t require reconfiguring dependencies or environments.
SOME TIPS-
- Avoid relying on
latestin production. - Store images in a secure registry with access control.
- Use semantic versioning for clarity and predictability.
- Automate tagging and pushing in your CI/CD pipeline.
- Maintain a changelog or link tags to Git commits for traceability.