error response from daemon: invalid CapDrop: capability not supported by your kernel or not available in the current environment: “CAP_MAC_ADMIN”
Error: failed to start containers:
Obviously Docker needs the capability mac_admin and some others too.
Our specific problem at this point is proxmox especially the lxc configuration not Docker by itself.
You can add the following line to your /etc/pve/nodes/pve/lxc/xxx.conflxc.cap.drop:
This will clear the cap drops.
Seems not the best solution for me but it works and Docker now gets what it needs.