Feat: ExpressVPN support (#623)

internal/configuration/expressvpn.go

@@ -0,0 +1,40 @@
+package configuration
+
+import (
+	"fmt"
+
+	"github.com/qdm12/gluetun/internal/constants"
+)
+
+func (settings *Provider) readExpressvpn(r reader) (err error) {
+	settings.Name = constants.Expressvpn
+	servers := r.servers.GetExpressvpn()
+
+	settings.ServerSelection.TargetIP, err = readTargetIP(r.env)
+	if err != nil {
+		return err
+	}
+
+	settings.ServerSelection.Hostnames, err = r.env.CSVInside("SERVER_HOSTNAME",
+		constants.ExpressvpnHostnameChoices(servers))
+	if err != nil {
+		return fmt.Errorf("environment variable SERVER_HOSTNAME: %w", err)
+	}
+
+	settings.ServerSelection.Countries, err = r.env.CSVInside("COUNTRY", constants.ExpressvpnCountriesChoices(servers))
+	if err != nil {
+		return fmt.Errorf("environment variable COUNTRY: %w", err)
+	}
+
+	settings.ServerSelection.Cities, err = r.env.CSVInside("CITY", constants.ExpressvpnCityChoices(servers))
+	if err != nil {
+		return fmt.Errorf("environment variable CITY: %w", err)
+	}
+
+	settings.ServerSelection.OpenVPN.TCP, err = readOpenVPNProtocol(r)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}