add log info messages

pkg/skaffold/build/builder_mux.go

@@ -20,6 +20,9 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"reflect"
+
+	"github.com/sirupsen/logrus"
 
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/graph"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/latest"
@@ -45,7 +48,7 @@ func NewBuilderMux(cfg Config, store ArtifactStore, builder func(p latest.Pipeli
 	m := make(map[string]PipelineBuilder)
 	var pb []PipelineBuilder
 	minConcurrency := -1
-	for _, p := range pipelines {
+	for i, p := range pipelines {
 		b, err := builder(p)
 		if err != nil {
 			return nil, fmt.Errorf("creating builder: %w", err)
@@ -55,13 +58,19 @@ func NewBuilderMux(cfg Config, store ArtifactStore, builder func(p latest.Pipeli
 			m[a.ImageName] = b
 		}
 		concurrency := b.Concurrency()
-		if minConcurrency < 0 {
+		// set mux concurrency to be the minimum of all builders' concurrency. (concurrency = 0 means unlimited)
+		switch {
+		case minConcurrency < 0:
 			minConcurrency = concurrency
-		} else if concurrency > 0 && (minConcurrency == 0 || concurrency < minConcurrency) {
-			// set mux concurrency to be the minimum of all builders' concurrency. (concurrency = 0 means unlimited)
+			logrus.Infof("build concurrency first set to %d parsed from %s[%d]", minConcurrency, reflect.TypeOf(b).String(), i)
+		case concurrency > 0 && (minConcurrency == 0 || concurrency < minConcurrency):
 			minConcurrency = concurrency
+			logrus.Infof("build concurrency updated to %d parsed from %s[%d]", minConcurrency, reflect.TypeOf(b).String(), i)
+		default:
+			logrus.Infof("build concurrency value %d parsed from %s[%d] is ignored since it's not less than previously set value %d", concurrency, reflect.TypeOf(b).String(), i, minConcurrency)
 		}
 	}
+	logrus.Infof("final build concurrency value is %d", minConcurrency)
 
 	return &BuilderMux{builders: pb, byImageName: m, store: store, concurrency: minConcurrency}, nil
 }