Allow links to be specified with only the name if this matches the alias

Signed-off-by: Antonio Murdaca <me@runcom.ninja>

parsers/parsers.go

@@ -135,3 +135,17 @@ func ParsePortRange(ports string) (uint64, uint64, error) {
 	}
 	return start, end, nil
 }
+
+func ParseLink(val string) (string, string, error) {
+	if val == "" {
+		return "", "", fmt.Errorf("empty string specified for links")
+	}
+	arr := strings.Split(val, ":")
+	if len(arr) > 2 {
+		return "", "", fmt.Errorf("bad format for links: %s", val)
+	}
+	if len(arr) == 1 {
+		return val, val, nil
+	}
+	return arr[0], arr[1], nil
+}

parsers/parsers_test.go

@@ -123,3 +123,35 @@ func TestParsePortRangeIncorrectStartRange(t *testing.T) {
 		t.Fatalf("Expecting error 'Invalid range specified for the Port' but received %s.", err)
 	}
 }
+
+func TestParseLink(t *testing.T) {
+	name, alias, err := ParseLink("name:alias")
+	if err != nil {
+		t.Fatalf("Expected not to error out on a valid name:alias format but got: %v", err)
+	}
+	if name != "name" {
+		t.Fatalf("Link name should have been name, got %s instead", name)
+	}
+	if alias != "alias" {
+		t.Fatalf("Link alias should have been alias, got %s instead", alias)
+	}
+	// short format definition
+	name, alias, err = ParseLink("name")
+	if err != nil {
+		t.Fatalf("Expected not to error out on a valid name only format but got: %v", err)
+	}
+	if name != "name" {
+		t.Fatalf("Link name should have been name, got %s instead", name)
+	}
+	if alias != "name" {
+		t.Fatalf("Link alias should have been name, got %s instead", alias)
+	}
+	// empty string link definition is not allowed
+	if _, _, err := ParseLink(""); err == nil || !strings.Contains(err.Error(), "empty string specified for links") {
+		t.Fatalf("Expected error 'empty string specified for links' but got: %v", err)
+	}
+	// more than two colons are not allowed
+	if _, _, err := ParseLink("link:alias:wrong"); err == nil || !strings.Contains(err.Error(), "bad format for links: link:alias:wrong") {
+		t.Fatalf("Expected error 'bad format for links: link:alias:wrong' but got: %v", err)
+	}
+}