Expose config for Watcher performance tuning

This changes the watcher to start with a performance config. We expose
ThreadsPerController, QPS and Burst for performance tuning as we do for
pipelines controller.

cmd/pipelines-as-code-watcher/main.go

@@ -8,7 +8,10 @@ import (
 	"time"
 
 	"github.com/openshift-pipelines/pipelines-as-code/pkg/reconciler"
+	"k8s.io/client-go/rest"
+	"knative.dev/pkg/injection"
 	"knative.dev/pkg/injection/sharedmain"
+	"knative.dev/pkg/signals"
 )
 
 const globalProbesPort = "8080"
@@ -44,5 +47,18 @@ func main() {
 	}()
 	<-c
 
-	sharedmain.Main("pac-watcher", reconciler.NewController())
+	// This parses flags.
+	cfg := injection.ParseAndGetRESTConfigOrDie()
+
+	if cfg.QPS == 0 {
+		cfg.QPS = 2 * rest.DefaultQPS
+	}
+	if cfg.Burst == 0 {
+		cfg.Burst = rest.DefaultBurst
+	}
+	// multiply by no of controllers being created
+	cfg.QPS = 5 * cfg.QPS
+	cfg.Burst = 5 * cfg.Burst
+	ctx := signals.NewContext()
+	sharedmain.MainWithConfig(ctx, "pac-watcher", cfg, reconciler.NewController())
 }