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Space - building a CMS with OVN Concepts#

OVS + OVN 2025 Fall Conference (Prague) digest Program Adjacent pick Prague · 19–20 November 2025

Abstract Slides Recording

Felix Huettner (StackIt)

Play the recording: Space - building a CMS with OVN Concepts

  • Why: An end-user case study of a cloud provider whose requirements (policy-based routing combined with dynamic routing, deny ACLs, per-ACL logging) outgrew Neutron — and who, rather than replacing OVN, built a custom CMS layer on OVN design concepts.
  • What: "spaced", a Go daemon using ovn-kubernetes' libovsdb, translating a custom "spacebound" OVSDB schema into the standard OVN northbound DB — effectively a custom northd. It coexists with Neutron through per-table resource ownership (either Neutron or spaced writes a given NB table), with a full migration off Neutron as the long-term goal.
  • How: Sticks to OVN's layered model (NB/SB/northd/ovn-controller), inserting spaced between the CMS and NB; the processing engine is modeled on OVN's incremental-processing engine (not yet implemented). Challenges listed honestly: libovsdb is event-driven with no consistent-state reads, no automatic reference resolution, and no change tracking.
  • Where applicable: StackIT / Schwarz Digits' OpenStack+OVN production environment — org-specific, but a useful template for anyone considering building a CMS directly on OVN primitives instead of adopting a full CMS.