feat(ivpn): allow no password for account IDs

- When matching `i-xxxx-xxxx-xxxx` username
- When matching `ivpn-xxxx-xxxx-xxxx` username

internal/configuration/settings/openvpn.go

@@ -2,6 +2,7 @@ package settings
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
@@ -73,6 +74,8 @@ type OpenVPN struct {
 	Flags []string
 }
 
+var ivpnAccountID = regexp.MustCompile(`^(i|ivpn)\-[a-zA-Z0-9]{4}\-[a-zA-Z0-9]{4}\-[a-zA-Z0-9]{4}$`)
+
 func (o OpenVPN) validate(vpnProvider string) (err error) {
 	// Validate version
 	validVersions := []string{constants.Openvpn24, constants.Openvpn25}
@@ -87,7 +90,10 @@ func (o OpenVPN) validate(vpnProvider string) (err error) {
 		return ErrOpenVPNUserIsEmpty
 	}
 
-	if !isCustom && o.Password == "" {
+	passwordRequired := !isCustom &&
+		(vpnProvider != constants.Ivpn || !ivpnAccountID.MatchString(o.User))
+
+	if passwordRequired && o.Password == "" {
 		return ErrOpenVPNPasswordIsEmpty
 	}
 

internal/configuration/settings/openvpn_test.go

@@ -0,0 +1,44 @@
+package settings
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_ivpnAccountID(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		s     string
+		match bool
+	}{
+		{},
+		{s: "abc"},
+		{s: "i"},
+		{s: "ivpn"},
+		{s: "ivpn-aaaa"},
+		{s: "ivpn-aaaa-aaaa"},
+		{s: "ivpn-aaaa-aaaa-aaa"},
+		{s: "ivpn-aaaa-aaaa-aaaa", match: true},
+		{s: "ivpn-aaaa-aaaa-aaaaa"},
+		{s: "ivpn-a6B7-fP91-Zh6Y", match: true},
+		{s: "i-aaaa"},
+		{s: "i-aaaa-aaaa"},
+		{s: "i-aaaa-aaaa-aaa"},
+		{s: "i-aaaa-aaaa-aaaa", match: true},
+		{s: "i-aaaa-aaaa-aaaaa"},
+		{s: "i-a6B7-fP91-Zh6Y", match: true},
+	}
+
+	for _, testCase := range testCases {
+		testCase := testCase
+		t.Run(testCase.s, func(t *testing.T) {
+			t.Parallel()
+
+			match := ivpnAccountID.MatchString(testCase.s)
+
+			assert.Equal(t, testCase.match, match)
+		})
+	}
+}