I'm still not entirely sold to a fixed amount of 2000 VLANs. According to https://en.wikipedia.org/wiki/IEEE_802.1Q you can have max 4094 VLANs (VID limitation). Also, if someone tries to set vlan_start to 3000 (due to some random company policy), you'll get invalid values. Also, some switches may only support a far lower number.

So I would make vlan_end configurable and add a check that vlan_start is above 0 and vlan_end is below 4095. This way we can always blame the cloud admin if things break :-)