Add Verify function to check if Ulimit max value is too big

When parsing the ulimit, we should check if the ulimit max value is greater then
the processes max value.  If yes then we should return an error.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

Author: rhatdan

ulimit.go

@@ -109,27 +109,15 @@ func ParseUlimit(val string) (*Ulimit, error) {
 	return &Ulimit{Name: parts[0], Soft: soft, Hard: *hard}, nil
 }
 
-// ParseUlimitAndVerify parses the value and verifyies that values work
-// with current kernel, returns a Ulimit from the specified string.
-func ParseUlimitAndVerify(val string) (*Ulimit, error) {
-	limit, err := ParseUlimit(val)
-	if err != nil {
-		return nil, err
-	}
-
-	parts := strings.Split(val, "=")
-	if len(parts) < 1 {
-		// this should never happen ParseUlimit should have caught this
-		return nil, fmt.Errorf("invalid ulimit argument: %s", val)
-	}
-
+// Verify that ulimit values work with current kernel
+func (u *Ulimit) Verify(limit Ulimit) error {
 	var rlimit syscall.Rlimit
 	if err := syscall.Getrlimit(ulimitNameMapping[parts[0]], &rlimit); err == nil {
-		if limit.Hard > int64(rlimit.Max) {
-			return nil, fmt.Errorf("ulimit hard limit must be less than or equal to hard limit for the current process, hard: %d", limit.Hard)
+		if u.Hard > int64(rlimit.Max) {
+			return fmt.Errorf("ulimit hard limit must be less than or equal to hard limit for the current process, hard: %d", limit.Hard)
 		}
 	}
-	return limit, nil
+	return nil
 }
 
 // GetRlimit returns the RLimit corresponding to Ulimit.

ulimit_test.go

@@ -22,8 +22,11 @@ func TestParseUlimitValid(t *testing.T) {
 }
 
 func TestParseUlimitTooBig(t *testing.T) {
-	if _, err := ParseUlimitAndVerify("nofile=512:1000024"); err == nil {
-		t.Fatalf("expected invalid value got %q", err)
+	if u, err := ParseUlimit("nofile=512:1000024"); err != nil {
+		t.Fatalf("expected valid value got %q", err)
+	}
+	if err := u.Verify(); err == nil {
+		t.Fatalf("expected invalid hard limit")
 	}
 }