h2. Original requirements We need a way to list the groups a user should be part of on the node they can log in to. Typical use cases: a) docker group b) admin group h2. Solution to implement The simplest thing that could possibly work: * can_login links grow a @groups@ property, an array of group name strings. * Workbench's user setup form has a text entry field for the administrator to enter a comma-separated list of group names. It turns this into an array and sends that as a parameter with the API setup request. * The script that actually creates shell accounts from can_login links creates group memberships from the new @groups@ property. We know that this method is susceptible to typos—it will silently fail to set the desired group memberships if the admin makes a mistake entering the group memberships in the setup form. We consider that an acceptable risk/limitation for now.