docker interface is not typically auto-connected - since this is a privileged interface. I also note the snap plugs the
docker-support interface - is this because you are shipping docker inside your snap? If this is the case, instead it would be better to use the docker snap directly for this via something like the following (see Snap that deploy a Docker image for an example of a similar request in the past) :
Also we do not normally grant auto-connect of the
docker interface since that essentially grants device ownership to the snap - instead we can grant use of the interface and then this has to be manually connected by the user. However, if you feel this should be auto-connected as well (since perhaps the use of docker is a primary function of Commandeer) then we can look into publisher vetting (as is done for granting classic confinement).