Inline cache

The inline cache storage backend is the simplest way to get an external cache and is easy to get started using if you’re already building and pushing an image. However, it doesn’t scale as well to multi-stage builds as well as the other drivers do. It also doesn’t offer separation between your output artifacts and your cache output. This means that if you’re using a particularly complex build flow, or not exporting your images directly to a registry, then you may want to consider the registry cache.

Synopsis

$ docker buildx build --push -t <registry>/<image> \
  --cache-to type=inline \
  --cache-from type=registry,ref=<registry>/image .

No additional parameters are supported for the inline cache.

To export cache using inline storage, pass type=inline to the --cache-to option:

$ docker buildx build --push -t <registry>/<image> \
  --cache-to type=inline .

Alternatively, you can also export inline cache by setting the build argument BUILDKIT_INLINE_CACHE=1, instead of using the --cache-to flag:

$ docker buildx build --push -t <registry>/<image> \
  --arg BUILDKIT_INLINE_CACHE=1 .

To import the resulting cache on a future build, pass type=registry to --cache-from which lets you extract the cache from inside a Docker image in the specified registry:

$ docker buildx build --push -t <registry>/<image> \
  --cache-from type=registry,ref=<registry>/<image> .

Further reading

For an introduction to caching see Optimizing builds with cache.

For more information on the inline cache backend, see the BuildKit README.