Make default logging less verbose.

At info level, log the latest known VCL mtime. Log all of the mtimes
at debug level.

pkg/apiclient/spec.go

@@ -315,11 +315,22 @@ func (updater *SpecUpdater) updatedVCLMap(
 	return
 }
 
+func (updater *SpecUpdater) latestVCLMtime() time.Time {
+	latest := time.Time{}
+	for _, t := range updater.vcls {
+		if t.After(latest) {
+			latest = t
+		}
+	}
+	return latest
+}
+
 // Update generates a new configuration from the current state of the
 // k8s cluster, and loads it as a new instance of VCL.
 func (updater *SpecUpdater) Update() error {
-	updater.log.Info("Update signal received")
-	updater.log.Info("Current VCL file modification times: ", updater.vcls)
+	updater.log.Debug("Current VCL file modification times: ", updater.vcls)
+	updater.log.Info("Current latest known VCL file modification time: ",
+		updater.latestVCLMtime())
 	spec, err := updater.getSpec()
 	if err != nil {
 		// XXX generate Warn event
@@ -361,7 +372,9 @@ func (updater *SpecUpdater) Update() error {
 	}
 	// XXX generate Info event, inc counter(?)
 	updater.vcls = updatedMap
-	updater.log.Info("Updated VCL file modification times: ", updater.vcls)
+	updater.log.Debug("Updated VCL file modification times: ", updater.vcls)
+	updater.log.Info("Updated latest known VCL file modification time: ",
+		updater.latestVCLMtime())
 	updater.log.Info("Varnish update succeeded")
 	return nil
 }