Fix #265 and refers to #256

- Logs a message about auth failure for PIA v4 servers

internal/logging/line.go

@@ -51,6 +51,9 @@ func PostProcessLine(s string) (filtered string, level logging.Level) {
 			level = logging.ErrorLevel
 		case s == "openvpn: Initialization Sequence Completed":
 			return color.HiGreenString(s), logging.InfoLevel
+		case s == "openvpn: AUTH: Received control message: AUTH_FAILED":
+			filtered = s + "\n\n  (IF YOU ARE USING PIA V4 servers, MAYBE CHECK OUT https://github.com/qdm12/gluetun/issues/265)\n" //nolint:lll
+			level = logging.ErrorLevel
 		default:
 			filtered = s
 			level = logging.InfoLevel

internal/logging/line_test.go

@@ -104,6 +104,10 @@ func Test_PostProcessLine(t *testing.T) {
 			"openvpn: Initialization Sequence Completed",
 			"openvpn: Initialization Sequence Completed",
 			logging.InfoLevel},
+		"openvpn auth failed": {
+			"openvpn: AUTH: Received control message: AUTH_FAILED",
+			"openvpn: AUTH: Received control message: AUTH_FAILED\n\n  (IF YOU ARE USING PIA V4 servers, MAYBE CHECK OUT https://github.com/qdm12/gluetun/issues/265)\n", //nolint:lll
+			logging.ErrorLevel},
 	}
 	for name, tc := range tests {
 		tc := tc