Build an image from a Dockerfile
Low risk
What do risk levels mean?
- Read-only
- Inspects state without changing anything.
- Low risk
- Reversible with a routine follow-up command.
- Medium risk
- Changes state; undo path documented.
- Destructive
- Deletes or overwrites; confirmation required.
Builds a Docker image from the Dockerfile in the current directory and tags it, so it can be run locally or pushed to a registry.
dockerbuildimagedockerfile
Parameters
Name and tag for the built image, such as myapp:dev.
Commands
Build the image from ./Dockerfile using the current directory as build context
docker build --tag <tag> .Confirm the built image exists and see its size
docker image ls <tag>Verification
docker image ls <tag>The image is listed with a recent CREATED time and a non-zero size.
Undo
Remove the image that this build created
docker rmi <tag>Pitfalls
- The whole current directory is sent as build context; add a .dockerignore to exclude large or sensitive files.
- Rebuilding with the same tag leaves the previous image as a dangling <none> image; prune occasionally.
- Use --file to point at a Dockerfile outside the current directory, and --no-cache to force a clean rebuild.