Managing IP Allocation with an Open-Source DDI#

Marco Martinez - Swisscom

• Why: IPAM is an explicit core interest, and this is a practitioner's build report: no open-source DDI exists today, so the speaker assembled one from three proven components rather than building DNS/DHCP/IPAM from scratch.
• What: A composable DDI built on Infrahub (IPAM/source of truth), Kea (DHCP), and PowerDNS (DNS), orchestrated by Event-Driven Ansible into a single event-driven configuration plane. The IPAM layer is authoritative: DNS entries and DHCP reservation pools are generated dynamically from the modeled dependencies in Infrahub.
• How: An earlier attempt (a "configuration plane" over the three products with separate automation tooling) failed on consistency; the working design makes Infrahub the source of truth, and events from it drive Ansible workflows that apply only the defined properties to Kea and PowerDNS — which keep their production-grade secure configuration for everything else. Reconciliation is built in. The result and code are published (github.com/marcom4rtinez/ddi).
• Where applicable: Environments priced out of commercial DDI (the stated motivation: cost, transparency, source of truth, moving out of silos). Honest limitations: HA and the "one vendor supports the whole stack" property of commercial DDI are what you give up; everything runs on containers/Linux and the integration complexity is higher than a monolithic product. Operator-specific in architecture choices, but the pattern (SoT generates DNS/DHCP, event-driven push, reconcile) is broadly reusable.