fix: add quiescenceRun flag to avoid render loops

When quiescence is configured and there are multiple templates, they
will trigger eachothers quiescence timers indefinitely. This can be
avoided by not ticking the timer of other templates when an individual
template's timer fires.

manager/runner.go

@@ -99,8 +99,12 @@ type Runner struct {
 	// quiescenceMap is the map of templates to their quiescence timers.
 	// quiescenceCh is the channel where templates report returns from quiescence
 	// fires.
+	// quiescenceRun is the template that was triggered to render via
+	// its respective timer. This flag is an optimization used to avoid infinite
+	// rendering when multiple templates exist.
 	quiescenceMap map[string]*quiescence
 	quiescenceCh  chan *template.Template
+	quiescenceRun *template.Template
 
 	// dedup is the deduplication manager if enabled
 	dedup *DedupManager
@@ -474,6 +478,7 @@ func (r *Runner) Start() {
 			// Remove the quiescence for this template from the map. This will force
 			// the upcoming Run call to actually evaluate and render the template.
 			log.Printf("[DEBUG] (runner) received template %q from quiescence", tmpl.ID())
+			r.quiescenceRun = tmpl
 			delete(r.quiescenceMap, tmpl.ID())
 
 		case c := <-childExitCh:
@@ -667,6 +672,9 @@ func (r *Runner) Run() error {
 		}
 	}
 
+	// Always reset quiescenceRun in case this run was triggered by a quiescence timer
+	r.quiescenceRun = nil
+
 	// Perform the diff and update the known dependencies.
 	r.diffAndUpdateDeps(runCtx.depsMap)
 
@@ -892,6 +900,13 @@ func (r *Runner) runTemplate(tmpl *template.Template, runCtx *templateRunCtx) (*
 		}
 	}
 
+	if r.quiescenceRun != nil && r.quiescenceRun != tmpl {
+		// During a run triggered via quiescence, mark any template not corresponding to
+		// the quiescence timer as ForQuiescence, signaling it was purposefully skipped.
+		event.ForQuiescence = true
+		return event, nil
+	}
+
 	// If quiescence is activated, start/update the timers and loop back around.
 	// We do not want to render the templates yet.
 	if q, ok := r.quiescenceMap[tmpl.ID()]; ok {