Improve empty result handler

README.md

@@ -110,6 +110,7 @@ Options:
   -l, --log=""                          Log to a file
   --all, --reportAll=true               Display all vulnerabilities, even if they are approved
   -r, --report=""                       Report output file, as JSON
+  --exit-when-no-features=false         Exit with status code 5 when no features are found for a particular image
 ```
 
 ## Example whitelist yaml file

main.go

@@ -26,7 +26,7 @@ func main() {
 		reportAll          = app.BoolOpt("all reportAll", true, "Display all vulnerabilities, even if they are approved")
 		reportFile         = app.StringOpt("r report", "", "Report output file, as JSON")
 		imageName          = app.StringArg("IMAGE", "", "Name of the Docker image to scan")
-		exitWhenNoFeatures = app.BoolOpt("exit-when-no-features", false, "Exit with status code 1 when no features are found for a particular image")
+		exitWhenNoFeatures = app.BoolOpt("exit-when-no-features", false, "Exit with status code 5 when no features are found for a particular image")
 	)
 
 	app.Before = func() {
@@ -54,7 +54,9 @@ func main() {
 			*reportAll,
 			*exitWhenNoFeatures,
 		})
-		if len(result) > 0 {
+		if result == nil {
+			os.Exit(5)
+		} else if len(result) > 0 {
 			os.Exit(1)
 		}
 	}

scanner.go

@@ -40,8 +40,8 @@ func scan(config scannerConfig) []string {
 	analyzeLayers(layerIds, config.clairURL, config.scannerIP)
 	vulnerabilities := getVulnerabilities(config, layerIds)
 
-	if len(vulnerabilities) == 0 {
-		return []string{}
+	if vulnerabilities == nil {
+		return nil; // exit when no features
 	}
 
 	//Check vulnerabilities against whitelist and report