IPVanish support (#475)

- Fix #410 and #416

internal/configuration/ipvanish.go

@@ -0,0 +1,52 @@
+package configuration
+
+import (
+	"github.com/qdm12/gluetun/internal/constants"
+)
+
+func (settings *Provider) ipvanishLines() (lines []string) {
+	if len(settings.ServerSelection.Countries) > 0 {
+		lines = append(lines, lastIndent+"Countries: "+commaJoin(settings.ServerSelection.Countries))
+	}
+
+	if len(settings.ServerSelection.Cities) > 0 {
+		lines = append(lines, lastIndent+"Cities: "+commaJoin(settings.ServerSelection.Cities))
+	}
+
+	if len(settings.ServerSelection.Hostnames) > 0 {
+		lines = append(lines, lastIndent+"Hostnames: "+commaJoin(settings.ServerSelection.Hostnames))
+	}
+
+	return lines
+}
+
+func (settings *Provider) readIpvanish(r reader) (err error) {
+	settings.Name = constants.Ipvanish
+
+	settings.ServerSelection.TCP, err = readProtocol(r.env)
+	if err != nil {
+		return err
+	}
+
+	settings.ServerSelection.TargetIP, err = readTargetIP(r.env)
+	if err != nil {
+		return err
+	}
+
+	settings.ServerSelection.Countries, err = r.env.CSVInside("COUNTRY", constants.IpvanishCountryChoices())
+	if err != nil {
+		return err
+	}
+
+	settings.ServerSelection.Cities, err = r.env.CSVInside("CITY", constants.IpvanishCityChoices())
+	if err != nil {
+		return err
+	}
+
+	settings.ServerSelection.Hostnames, err = r.env.CSVInside("SERVER_HOSTNAME", constants.IpvanishHostnameChoices())
+	if err != nil {
+		return err
+	}
+
+	return nil
+}