It resolves issues #474 and #589 which were coming from libcompose,
as well as resolves#440 and #437 partially as `group_add` & `stop_grace_period`
are supported by libcompose now.
This adds github.com/pkg/errors to glide.yaml followed
by glide and glide-vc commands. The github.com/pkg/errors
package is currently required mainly for the errors.Wrap()
and errors.New() methods, since this lets us to annotate the
errors while passing the error message up the call stack.
Implements a kompose specific docker compose label "kompose.service.expose" which can be used to expose the specified services externally. The accepted values are of type string.
If the value is set to "true", the provider sets the endpoint automatically, and for any other value, the value is set as the hostname. If multiple ports are defined in a service, the first one is chosen to be the exposed.
Unit tests, functional tests, glide updates and docs have also been added in this commit for the related feature.
