feat:[CI-15236]: Added IMAGE_TAR_PATH as output variable for the plugin.

kaniko.go

@@ -407,14 +407,26 @@ func (p Plugin) Exec() error {
 	}
 
 	if p.Output.OutputFile != "" {
-		if err = output.WritePluginOutputFile(p.Output.OutputFile, getDigest(p.Build.DigestFile)); err != nil {
+		if err = output.WritePluginOutputFile(p.Output.OutputFile, getDigest(p.Build.DigestFile), getTarPath(p.Build.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
 }
 
+func getTarPath(tarPath string) string {
+	if tarPath == "" {
+		fmt.Fprintf(os.Stderr, "Warning: tar_path is empty\n")
+		return ""
+	}
+	if _, err := os.Stat(tarPath); err != nil && os.IsNotExist(err) {
+		fmt.Fprintf(os.Stderr, "Warning: tar path does not exist: %s\n", tarPath)
+		return ""
+	}
+	return tarPath
+}
+
 func getDigest(digestFile string) string {
 	content, err := ioutil.ReadFile(digestFile)
 	if err != nil {

pkg/output/output.go

@@ -1,12 +1,23 @@
 package output
 
 import (
+	"fmt"
 	"github.com/joho/godotenv"
 )
 
-func WritePluginOutputFile(outputFilePath, digest string) error {
-	output := map[string]string{
-		"digest": digest,
+func WritePluginOutputFile(outputFilePath, digest string, pluginTarPath string) error {
+	output := make(map[string]string)
+	if digest != "" {
+		output["digest"] = digest
 	}
+
+	if pluginTarPath != "" {
+		output["IMAGE_TAR_PATH"] = pluginTarPath
+	}
+
+	if len(output) == 0 {
+		return fmt.Errorf("no values to write to output file")
+	}
+
 	return godotenv.Write(output, outputFilePath)
 }