Introducing option to disable log coloring

NSM issue: networkservicemesh#1594

Signed-off-by: Botond Szirtes <botond.szirtes@est.tech>

pkg/tools/log/logruslogger/formatter.go

@@ -18,6 +18,7 @@ package logruslogger
 
 import (
 	"bytes"
+	"os"
 	"strings"
 
 	nested "github.com/antonfisher/nested-logrus-formatter"
@@ -33,6 +34,9 @@ type formatter struct {
 func newFormatter() *formatter {
 	f := formatter{}
 	f.nf.FieldsOrder = []string{"id", "name"}
+	if os.Getenv("LOG_NOCOLORS") == "true" {
+		f.nf.NoColors = true
+	}
 	return &f
 }
 
@@ -53,10 +57,16 @@ func (f *formatter) Format(entry *logrus.Entry) ([]byte, error) {
 	bb := &bytes.Buffer{}
 
 	split := strings.SplitN(bytesString, "\x1b[0m", 2)
-	prefix := split[0] + "\x1b[0m"
-	split[1] = split[1][:len(split[1])-1] // remove trailing \n
+
+	prefix := ""
+	if !f.nf.NoColors {
+		prefix = split[0] + "\x1b[0m"
+		split = split[1:]
+	}
+
+	split[0] = split[0][:len(split[0])-1] // remove trailing \n
 	bb.WriteString(prefix)
-	for _, line := range strings.Split(split[1], "\n") {
+	for _, line := range strings.Split(split[0], "\n") {
 		bb.WriteString(line)
 		bb.WriteString(";\t")
 	}