Support new input ignore_paths to all the supported versions of Kaniko

cmd/kaniko-docker/main.go

@@ -353,7 +353,7 @@ func main() {
 			Usage:  "Path to ignore during the build.",
 			EnvVar: "PLUGIN_IGNORE_PATH",
 		},
-		cli.StringSliceFlag{
+		cli.StringFlag{
 			Name:   "ignore-paths",
 			Usage:  "Path to ignore during the build.",
 			EnvVar: "PLUGIN_IGNORE_PATHS",

kaniko.go

@@ -483,13 +483,14 @@ func (p Plugin) Exec() error {
 		}
 	}
 
-	p.Output.OutputFile = os.Getenv("DRONE_OUTPUT")
-	var tarPath string
-	if p.Build.TarPath != "" {
-		tarPath = getTarPath(p.Build.TarPath)
-	}
-	if err = output.WritePluginOutputFile(p.Output.OutputFile, getDigest(p.Build.DigestFile), tarPath); err != nil {
-		fmt.Fprintf(os.Stderr, "failed to write plugin output file at path: %s with error: %s\n", p.Output.OutputFile, err)
+	if p.Output.OutputFile != "" {
+		var tarPath string
+		if p.Build.TarPath != "" {
+			tarPath = getTarPath(p.Build.TarPath)
+		}
+		if err = output.WritePluginOutputFile(p.Output.OutputFile, getDigest(p.Build.DigestFile), tarPath); err != nil {
+			fmt.Fprintf(os.Stderr, "failed to write plugin output file at path: %s with error: %s\n", p.Output.OutputFile, err)
+		}
 	}
 
 	return nil