A marker is single-sided — only the chosen capture node's uBridge installs the
mark filter — and dir=tx|rx is interpreted from that node's perspective. Until
now the observer was always auto-picked (_choose_marker_side), so dir=tx meant
"the auto-chosen endpoint is sending", which is unpredictable and makes the
direction filter hard to render meaningfully in the Web UI.
Add an optional create-only capture_node_id to MarkerCreate: when set, the
marker is pinned to that endpoint's uBridge (validated as a link endpoint and a
marker-capable type); when omitted, behavior is unchanged (auto-pick). The
chosen id is already echoed back as capture_node_id and in MARK signals, so the
UI can always render the observer regardless of who picked it.
capture_node_id is create-only (changing it would silently flip the meaning of
stored direction; recreate instead) and is not accepted on project-level
definitions — they are link-agnostic and have no endpoints, so inherited
markers keep auto-picking per link.
Plumbed through REST create_marker, the MCP link_marker tool, and base
Link.start_marker. update_marker does not forward it.
Direction field in marker.match events
=======================================
Read ubridge dir=<tx|rx> from MARK signal datagrams and forward it
as a "dir" key in the marker.match notification event. The field is
additive -- older ubridge builds omit it and the parser leaves it null,
so consumers fall back to undirected rendering with no version coupling.
Semantics are relative to the capture node (the signal's node=<id>):
tx = capture node is sending (ingressed device-side NIO), rx = it is
receiving (ingressed link-side NIO).
Per-marker direction filter (opt-in, server-side pipeline)
==========================================================
Add a direction field to MarkerCreate and MarkerDefinitionCreate
schemas ("tx" | "rx" | null). Plumb it through the full pipeline:
Schema -> controller (start_marker/update_marker, marker_entry,
_markers_for_node, update_marker_definition sync)
-> REST/MCP handlers -> compute _ubridge_add_marker_filter +
IOU _ubridge_apply_markers -> bridge add_packet_filter dir <tx|rx>
When set, ubridge only fires the mark handler (signal + pcap) for
packets matching the chosen direction. null (default/legacy) = both
directions -- zero behavioural change for existing markers.
Docs and tests
==============
- docs/features/marker-traffic-insight.md: signal format updated,
new Direction section with NIO mapping, arrow mapping, and additive
compatibility note.
- tests/compute/marker/test_marker_manager.py: 3 new parser tests
(dir tx/rx/absent) plus existing test extended to assert dir=None.
13 files, +123/-22, 72 tests pass (zero breakage)
Add a Per-link attribution section (link field semantics, pcap path keyed on link) with an IOU subsection explaining the shared IOL-BRIDGE and per-port filter lists. Note that the marker.match link_id comes from the signal link= field, and call out shared capture-side node behavior in Notes.
Document the marker feature following the gns3-documentation standard:
overview, Mermaid architecture and business-process diagrams, API endpoint
tables, request/response and field reference, error responses, and notes
covering the key design points — immutable name (rename = delete + create),
global-prefix reservation, read-only inherited markers, render hints
(color / highlight_duration), supported node types, and persistence.
Indexed under Features in docs/README.md.
