Fix too many open files

Factored validate file into own func, the defer was not being
called on each iteration. This results in the tool keeping
every KEP yaml open during execution.

Author: bowei

pkg/repo/validate.go

@@ -84,41 +84,22 @@ func (r *Repo) Validate() (
 		return warnings, valErrMap, errors.New("must find more than zero KEPs")
 	}
 
-	kepHandler, prrHandler := r.KEPHandler, r.PRRHandler
 	prrDir := r.PRRApprovalPath
 	logrus.Infof("PRR directory: %s", prrDir)
 
 	for _, filename := range files {
-		kepFile, err := os.Open(filename)
-		if err != nil {
-			return warnings, valErrMap, errors.Wrapf(err, "could not open file %s", filename)
-		}
-
-		defer kepFile.Close()
-
-		logrus.Infof("parsing %s", filename)
-		kep, kepParseErr := kepHandler.Parse(kepFile)
-		if kepParseErr != nil {
-			return warnings, valErrMap, errors.Wrap(kepParseErr, "parsing KEP file")
-		}
-		kep.Filename = filename
-
-		// TODO: This shouldn't be required once we push the errors into the
-		//       parser struct
-		if kep.Error != nil {
-			return warnings, valErrMap, errors.Wrapf(kep.Error, "%v has an error", filename)
-		}
-
-		err = kepval.ValidatePRR(kep, prrHandler, prrDir)
-		if err != nil {
+		if err := validateFile(r, prrDir, filename); err != nil {
+			fvErr := &fatalValidationError{}
+			if errors.As(err, fvErr) {
+				return warnings, valErrMap, err
+			}
 			valErrMap[filename] = append(valErrMap[filename], err)
 		}
 	}
 
 	if len(valErrMap) > 0 {
 		for filename, errs := range valErrMap {
 			logrus.Infof("the following PRR validation errors occurred in %s:", filename)
-
 			for _, e := range errs {
 				logrus.Infof("%v", e)
 			}
@@ -127,3 +108,35 @@ func (r *Repo) Validate() (
 
 	return warnings, valErrMap, nil
 }
+
+// fatalValidationError will short-circuit KEP parsing and return early.
+type fatalValidationError struct{ Err error }
+
+func (e fatalValidationError) Error() string { return e.Err.Error() }
+func (e fatalValidationError) Unwrap() error { return e.Err }
+
+// validateFile runs a validation and returns an error if validation fails.
+// fatalValidationError will be returned if further parsing should be stopped.
+func validateFile(r *Repo, prrDir, filename string) error {
+	kepFile, err := os.Open(filename)
+	if err != nil {
+		return &fatalValidationError{Err: errors.Wrapf(err, "could not open file %s", filename)}
+	}
+	defer kepFile.Close()
+
+	logrus.Infof("parsing %s", filename)
+	kepHandler, prrHandler := r.KEPHandler, r.PRRHandler
+	kep, kepParseErr := kepHandler.Parse(kepFile)
+	if kepParseErr != nil {
+		return errors.Wrap(kepParseErr, "parsing KEP file")
+	}
+	kep.Filename = filename
+
+	// TODO: This shouldn't be required once we push the errors into the
+	//       parser struct
+	if kep.Error != nil {
+		return &fatalValidationError{Err: errors.Wrapf(kep.Error, "%v has an error", filename)}
+	}
+
+	return kepval.ValidatePRR(kep, prrHandler, prrDir)
+}