Create a Docker Image From a Container
One of the Nautilus developer was working to test new changes on a container. He wants to keep a backup of his changes to the container. A new request has been raised for the DevOps team to create a new image from this container. Below are more details about it:
- Create an image
ecommerce:nautilus on Application Server 3 from a container ubuntu_latest that is running on same server.
Steps
To create a docker image from a running container, we can use the following command:
docker commit container-name image-repository:tag
In this case, the actual command is:
docker commit ubuntu_latest ecommerce:nautilus
Good to Know?
Docker Commit
- Purpose: Create new image from container’s changes
- Snapshot: Captures current state of container
- Layer Addition: Adds new layer on top of base image
- Persistence: Preserves modifications made to container
When to Use Commit
- Quick Prototyping: Rapid image creation during development
- Manual Changes: Capture manual configurations
- Debugging: Save state for later analysis
- Backup: Create checkpoint of working container
Commit vs Dockerfile
- Dockerfile: Preferred for production (reproducible, version-controlled)
- Commit: Good for experimentation and quick fixes
- Transparency: Dockerfile shows exact build steps
- Automation: Dockerfile enables automated builds
Best Practices
- Documentation: Add commit message explaining changes
- Minimize Layers: Avoid excessive commits
- Clean State: Remove temporary files before commit
- Dockerfile Migration: Convert successful commits to Dockerfile