Automating the provisioning of 5G services, deployed over a heterogeneous infrastructure (in terms of domains, technologies, and management platforms), remains a complex task, yet driven by the constant need to provide end-to-end connections at network slices at reducing costs and service deployment time. At the same time, such services are increasingly conceived around interconnected functions and require allocation of computing, storage, and networking resources. The METRO-HAUL 5G research initiative acknowledges the need for automation and strives to develop an orchestration platform for services and resources that extends, integrates, and builds on top of existing approaches, macroscopically adopting Transport Software Defined Networking principles, and leveraging the programmability and open control of Transport SDN.