VMware's ongoing embrace of containers has expanded with the release of Harbor, an open source project that adds enterprise-level features to Docker. It could prove enticing to smaller outfits wary of the costs associated with the full enterprise-level Docker.
Harbor is a reworking of the existing Docker distribution with enterprise-specific features rolled in. Users can be authenticated and managed through Active Directory/LDAP, and they can have role-based access controls and permissions assigned to them for specific tasks.
Repositories, and users working on then, can be grouped together as projects and have permissions associated with them. Thus, project leads can have greater control over the codebase than mere contributors. (Auditing user behavior is also built in.)
VMware Harbor provides enterprise extensions to Docker, including the ability to assign RBACs or behavioral policies to objects, or to users manageable through Active Directory or LDAP.
Harbor also provides degrees of convenience and automation for Docker that aren't available out of the box. If you have multiple Docker Registry instances, for instance, Harbor can automatically replicate images between them. Most of Harbor's functions are available through a web-based user portal, but they're also exposed via a RESTful API for automation's sake.
Many of Harbor's features so far are not very flexible. With RBACs, for instance, users can't add custom roles (unless they want to modify the source code). Only four built-in roles are provided -- Guest, Developer, Project Admin, and Sysadmin -- although they should cover the majority of use cases for the time being.
Docker Enterprise also appeals to enterprises with included for-pay support. But Harbor's roster of features is useful enough to outfits of most any size that its best attributes seem likely to become part of the default open source Docker distribution.