fix: overwrite the output file when repetedly executing kyverno apply…

… command (#1701)

Signed-off-by: Yashvardhan Kukreja <yash.kukreja.98@gmail.com>

pkg/kyverno/apply/command.go

@@ -205,6 +205,18 @@ func applyCommandHelper(resourcePaths []string, cluster bool, policyReport bool,
 		return validateEngineResponses, rc, resources, skippedPolicies, err
 	}
 
+	// empty the previous contents of the file just in case if the file already existed before with some content(so as to perform overwrites)
+	// the truncation of files for the case when mutateLogPath is dir, is handled under pkg/kyverno/apply/common.go
+	if !mutateLogPathIsDir {
+		_, err := os.OpenFile(mutateLogPath, os.O_TRUNC|os.O_WRONLY, 0644)
+		if err != nil {
+			if !sanitizederror.IsErrorSanitized(err) {
+				return validateEngineResponses, rc, resources, skippedPolicies, sanitizederror.NewWithError("failed to truncate the existing file at "+mutateLogPath, err)
+			}
+			return validateEngineResponses, rc, resources, skippedPolicies, err
+		}
+	}
+
 	mutatedPolicies, err := common.MutatePolices(policies)
 	if err != nil {
 		if !sanitizederror.IsErrorSanitized(err) {

pkg/kyverno/common/common.go

@@ -537,9 +537,10 @@ func PrintMutatedOutput(mutateLogPath string, mutateLogPathIsDir bool, yaml stri
 	yaml = yaml + ("\n---\n\n")
 
 	if !mutateLogPathIsDir {
+		// truncation for the case when mutateLogPath is a file (not a directory) is handled under pkg/kyverno/apply/command.go
 		f, err = os.OpenFile(mutateLogPath, os.O_APPEND|os.O_WRONLY, 0644)
 	} else {
-		f, err = os.OpenFile(mutateLogPath+"/"+fileName+".yaml", os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+		f, err = os.OpenFile(mutateLogPath+"/"+fileName+".yaml", os.O_CREATE|os.O_WRONLY, 0644)
 	}
 
 	if err != nil {