This section defines a format for encoding a container as a filesystem bundle - a set of files organized in a certain way, and containing all the necessary data and metadata for any compliant runtime to perform all standard operations against it. See also MacOS application bundles for a similar use of the term bundle.
The definition of a bundle is only concerned with how a container, and its configuration data, are stored on a local filesystem so that it can be consumed by a compliant runtime.
A Standard Container bundle contains all the information needed to load and run a container. This includes the following artifacts:
-
config.json
: contains configuration data. This REQUIRED file MUST reside in the root of the bundle directory and MUST be namedconfig.json
. Seeconfig.json
for more details. -
container's root filesystem: the directory referenced by
root.path
, if that property is set inconfig.json
.
When supplied, while these artifacts MUST all be present in a single directory on the local filesystem, that directory itself is not part of the bundle. In other words, a tar archive of a bundle will have these artifacts at the root of the archive, not nested within a top-level directory.