Merge pull request 'A machine says what it is made of, and says it once a day unasked (issue 160)' (#92) from fix/160-a-machine-says-what-it-is into main

cmd/mesh-host/main.go

@@ -1358,6 +1358,32 @@ type adoptionWatch struct {
 	last string
 	// faulty is whether the last report the mesh heard said an apply refused or failed (novox/hq issue 233).
 	faulty bool
+	// machineSaid is when the mesh last heard what this machine is made of (novox/hq issue 160), and now the
+	// clock it is judged by (time.Now when nil).
+	machineSaid time.Time
+	now         func() time.Time
+}
+
+// machineEvery is how old what a machine said of itself may grow before a reconcile says it again unasked
+// (novox/hq issue 160): a machine nobody pushed to still says it once a day, so no fact the mesh holds of it
+// is older than a day. Under a day by more than one reconcile interval, so the reconcile that says it falls
+// inside the day rather than just past it.
+const machineEvery = 23 * time.Hour
+
+// clock is the wall time, its monotonic reading stripped (Round(0)). **Wall, because a laptop sleeps**: Go's
+// monotonic clock does not advance while the machine is suspended, so a day judged by it on a laptop that slept
+// for half of it is a day and a half of wall time, and what the mesh holds of the machine is older than a day.
+func (w *adoptionWatch) clock() time.Time {
+	if w.now != nil {
+		return w.now().Round(0)
+	}
+	return time.Now().Round(0)
+}
+
+// machineDue is whether a report carries what the machine is made of and the mesh last heard it a day ago
+// or more. A refusal carries none, so it never is.
+func (w *adoptionWatch) machineDue(r link.Report) bool {
+	return r.Refused == "" && len(r.Profile) > 0 && w.clock().Sub(w.machineSaid) >= machineEvery
 }
 
 // fingerprint is what a report says about adoption: each hold and whether it changed, the
@@ -1422,7 +1448,8 @@ func applyState(r link.Report) string {
 // faulty is whether a report says an apply refused or failed.
 func faulty(r link.Report) bool { return r.Refused != "" || len(r.Failed) > 0 }
 
-// news is whether a reconcile's report is worth saying unasked: it says something the last one the mesh heard
+// news is whether a reconcile's report is worth saying unasked: what the machine is made of last reached the
+// mesh a day ago or more (novox/hq issue 160); or it says something the last one the mesh heard
 // did not, and it is about the machine (worthSaying) — or about how the apply went, refused or failed now, or
 // clean after the last one the mesh heard was not (novox/hq issue 233). A refusal says nothing about the
 // machine, but that the machine refuses is what the mesh raises a condition from, and a clean apply after it is
@@ -1430,6 +1457,10 @@ func faulty(r link.Report) bool { return r.Refused != "" || len(r.Failed) > 0 }
 func (w *adoptionWatch) news(r link.Report) bool {
 	w.mu.Lock()
 	defer w.mu.Unlock()
+	// What the machine is made of, once a day whatever else changed (novox/hq issue 160).
+	if w.machineDue(r) {
+		return true
+	}
 	if adoptionFingerprint(r) == w.last {
 		return false
 	}
@@ -1450,6 +1481,9 @@ func (w *adoptionWatch) said(r link.Report) {
 	defer w.mu.Unlock()
 	w.last = adoptionFingerprint(r)
 	w.faulty = faulty(r)
+	if len(r.Profile) > 0 {
+		w.machineSaid = w.clock()
+	}
 }
 
 // changed is differs and said together, for a report published as it is made.