Many others have already recommended these, but I suggest installing test VMs of both phpipam and nipap and seeing which works best for your use case.

NIPAP has fairly extensive tools supporting automation for provisioning. phpipam has a few additional functions on top of only ip address management, it also appears to have been designed for a use case where people are running geographically spread out layer 2 services and keeping track of which vlan belongs to which customer.