Simon Law
cb7e536804
Previously, refreshing the routecheck.Client would probe to generate a new routecheck.Report, but this method was only wired up to the LocalAPI and the `tailscale routecheck` command. However, waiting for a probe to finish before choosing a router would take too long, so we must keep a regularly updated report to be consulted as necessary. This patch adds a Start and Close method to the routecheck.Client and starts it in the background from features/routecheck. To enable this feature for a given node, set both of the following node attributes: `client-side-reachability` and `client-side-reachability-routecheck`. This patch also wires up the RouterTracker.OnRoutersChange hook, which fires a callback whenever a new network map includes information about a router node, This signals to the routecheck.Client that it might need to schedule another probe, if the shape of the routing table has changed materially. Updates #17366 Updates tailscale/corp#33033 Signed-off-by: Simon Law <sfllaw@tailscale.com>
69 lines
1.9 KiB
Go
69 lines
1.9 KiB
Go
// Copyright (c) Tailscale Inc & contributors
|
||
// SPDX-License-Identifier: BSD-3-Clause
|
||
|
||
package routecheck
|
||
|
||
import (
|
||
"net/http"
|
||
"time"
|
||
|
||
jsonv2 "github.com/go-json-experiment/json"
|
||
jsonv1 "github.com/go-json-experiment/json/v1"
|
||
|
||
"tailscale.com/ipn/localapi"
|
||
"tailscale.com/net/routecheck"
|
||
"tailscale.com/util/def"
|
||
"tailscale.com/util/httpm"
|
||
)
|
||
|
||
func init() {
|
||
localapi.Register("routecheck", serveRouteCheck)
|
||
}
|
||
|
||
// ServeRouteCheck handles the API endpoint that serves the routecheck Report.
|
||
// If the probe form field is true, then this handler will refresh the Report
|
||
// before serving it.
|
||
// If the timeout form field is a valid duration, the probe will consider a node
|
||
// to be unreachable if it doesn’t respond before the timeout expires.
|
||
func serveRouteCheck(h *localapi.Handler, w http.ResponseWriter, r *http.Request) {
|
||
rc := ClientFor(h.LocalBackend())
|
||
if rc == nil {
|
||
http.Error(w, "routecheck is not enabled", http.StatusServiceUnavailable)
|
||
return
|
||
}
|
||
|
||
if r.Method != httpm.POST {
|
||
http.Error(w, "want POST", http.StatusMethodNotAllowed)
|
||
return
|
||
}
|
||
|
||
report := rc.Report()
|
||
if def.Bool(r.FormValue("probe"), false) {
|
||
timeout := def.Duration(r.FormValue("timeout"), routecheck.DefaultTimeout)
|
||
timeout = clampRouteCheckTimeout(timeout)
|
||
rp, err := rc.Refresh(r.Context(), timeout)
|
||
if err != nil {
|
||
localapi.WriteErrorJSON(w, err)
|
||
return
|
||
}
|
||
report = rp
|
||
}
|
||
|
||
w.Header().Set("Content-Type", "application/json")
|
||
if report == nil {
|
||
w.WriteHeader(http.StatusNoContent)
|
||
return
|
||
}
|
||
|
||
// TODO(sfllaw): Since ipn/localapi is still using encoding/json
|
||
// with its default options, marshal with DefaultOptionsV1.
|
||
jsonv2.MarshalWrite(w, report, jsonv1.DefaultOptionsV1())
|
||
}
|
||
|
||
func clampRouteCheckTimeout(timeout time.Duration) time.Duration {
|
||
if timeout < 0 {
|
||
timeout = routecheck.DefaultTimeout
|
||
}
|
||
return min(max(0, timeout), 60*time.Second) // clamp to [0s, 60s]
|
||
}
|