Docker tags
Tagging helps developers to version images. An image can contain any number of tags. Developers or operators using the image can download/pull a particular version using the tag name. A tag name can consist of numbers, lowercase or uppercase alphabets, underscores, periods, and dashes. The following command creates a new image with v1.0
as the tag name and learningwsc/mycustomwebserver
as the image name where learningwsc
is the Docker Hub username and mycustomwebserver
is the name of my image:
docker build -t learningwsc/mycustomwebserver:v1.0 .
The Docker daemon is intelligent enough to avoid downloads of redundant layers when working with multiple tags of the same image. When the users download the image with a tag, docker checks for existing layers on the host machine and the differential set of the image, or say only the latest layers are downloaded, this makes software really thin and easily portable.
If not specified the latest is used as the default tag. Tagging information...