When --vmtest-web is set, Host.app is launched with --screenshot-port 0
to start a localhost HTTP server that captures the VZVirtualMachineView
display. The Go test harness parses the SCREENSHOT_PORT=<port> line from
stdout, then polls every 2 seconds for JPEG thumbnails and pushes them
over WebSocket to the web dashboard.
Clicking a screenshot thumbnail opens a full-resolution image proxied
through the web UI's /screenshot/{node} endpoint.
Screenshot events are excluded from the EventBus history (they're large
and only the latest matters, stored in NodeStatus.Screenshot).
Updates #13038
Change-Id: I9bc67ddd1cc72948b33c555d4be3d8db06a41f6d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Add an optional --vmtest-web flag that starts an HTTP server showing a
live dashboard for vmtest runs. The dashboard includes:
- Step progress tracker showing all test phases (compile, image prep,
QEMU launch, agent connect, tailscale up, test-specific steps)
with status icons and elapsed times
- Per-VM "virtual monitor" cards showing serial console output
streamed in realtime via WebSocket
- Per-NIC DHCP status (supporting multi-homed VMs like subnet routers)
- Per-node Tailscale status (hidden for non-tailnet VMs)
- Test status badge (Running/Passed/Failed) with live elapsed timer
- Event log showing all lifecycle events chronologically
Architecture follows the existing util/eventbus HTMX+WebSocket pattern:
the server pushes HTML fragments with hx-swap-oob attributes over a
WebSocket, and HTMX routes them to the correct DOM elements by ID.
Key components:
- vmstatus.go: Step tracker (Begin/End lifecycle), EventBus (pub/sub
with history for late joiners), VMEvent types, NodeStatus tracking
- web.go: HTTP server, WebSocket handler, template loading, ANSI-to-HTML
conversion via robert-nix/ansihtml, deterministic port selection
- assets/: HTML templates, CSS, HTMX library (copied from eventbus)
- vnet/vnet.go: DHCP event callback on Server for observing DHCP lifecycle
- qemu.go: Console log file tailing with manual offset-based reading
Usage:
go test ./tstest/natlab/vmtest/ --run-vm-tests --vmtest-web=:0 -v
When using :0, a deterministic port based on the test name is tried
first so re-runs get the same URL, falling back to OS-assigned on
conflict.
Updates #13038
Change-Id: I45281347b3d7af78ed9f4ff896033984f84dcb4d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
