* Create a MultiPublisher
MultiPublisher mimics io.MultiWriter in that it will publish an image to
multiple publish.Interface implementations.
* Add publish.{Tarball,Layout}Publisher
This adds support for publishing in the tarball format and to an OCI
image layout.
The tarball format isn't great, yet. It only supports writing once
instead of appending.
* Consolidate options
These were spread all over the place for no reasons. Now all the
publisher related options are grouped together.
* Add options for tarball/layout
Adds --oci-layout-path, --tarball, and --push flags.
--push=false will disable the default behavior of publishing to a
registry.
* go mod vendor
* Add Close method to publish.Interface
This allows us to defer writing to the tarball until we've collected all
the images that have been published.
* Fix tests
* Add build.Limiter
You can limit the number of concurrent builds with -j (a la make).
The default value for this is GOMAXPROCS, which seems reasonable.
When ko is invoked in this mode, import paths must have the `ko://`
prefix. If a human marks an import path with `ko://` and ko can't
resolve the resulting import path, it fails. In "loose mode", such an
import path would be silently ignored and passed on to the resolved
YAML, often resulting in invalid image names (e.g., `image:
github.com/foo/bar`)
In loose mode, `ko://` prefixes are always ignored for
backward-compatibility.
Why this is necessary: when using a local docker registry, users may not
want to support https, or there may be other troubles not allowing
verifiable TLS support.
This commit adds this functionality by adding an `--insecure-registry`
flag.
