Images evolve over time and their tags reflect this. Generally, an image tag always points to the latest image built.
If there is too much information embedded in a tag name, like
v2.0.1-may-2019, the tag points to just one revision of an image and is
never updated. Using default image pruning options, such an image is never
removed.
If the tag is named v2.0, image revisions are more likely. This
results in longer tag history and, therefore, the image pruner is more likely to
remove old and unused images.
Although tag naming convention is up to you, here are a few examples in the
format <image_name>:<image_tag>:
| Description | Example |
|---|---|
Revision |
|
Architecture |
|
Base image |
|
Latest (potentially unstable) |
|
Latest stable |
|
If you require dates in tag names, periodically inspect old and unsupported
images and istags and remove them. Otherwise, you can experience increasing
resource usage caused by retaining old images.