Web clients serialize empty form fields as "" while unset values are
stored as None on the node. The bare != diff in the update handler then
sees a phantom change on every full PUT and recreates the container for
nothing -- even when the user only changed a controller-only field such
as netmiko_device_type.
Normalize at the schema boundary ("" -> None for start_command,
environment and extra_hosts; "" -> "/" for console_http_path), make
the setters apply the same canonicalization, and create nodes through
the setters instead of bypassing them in __init__ so both paths store
identical values.
Project open used to create each link by issuing two NIO POSTs from the
controller to the compute — ~5000 HTTP round-trips for a 2500-link
topology, all funnelling through the single shared controller/compute
event loop and capping throughput near 12 links/s.
Replace it with a bulk path:
- UDPLink split into _prepare() (local: ports, peer addrs, link_data)
and _commit_nios() (dispatch). create() = prepare + commit (interactive).
- Link.add_node gains batch=True: attach both nodes without triggering
per-link NIO HTTP.
- compute: new POST /projects/{id}/nios/batch endpoint with a unified
_add_nio_binding dispatch across node types (docker/qemu/iou/vpcs/
builtin differ in signature).
- project.open: prepare all links locally, group NIO entries by compute,
send each compute a single /nios/batch, then finalise (wire node/port
refs, mark created, notify, apply marker defs) in parallel.
Cuts controller->compute HTTP from O(links) to O(computes). Test added
for the batch endpoint.
