Maint: internal/storage rework

- No more global variables
- Inject merged servers to configuration package
- Fix #566: configuration parsing to use persisted servers.json
- Move server data files from `internal/constants` to `internal/storage`

internal/provider/cyberghost/filter.go

@@ -17,9 +17,9 @@ func (c *Cyberghost) filterServers(selection configuration.ServerSelection) (
 	servers []models.CyberghostServer, err error) {
 	if len(selection.Groups) == 0 {
 		if selection.OpenVPN.TCP {
-			selection.Groups = tcpGroupChoices()
+			selection.Groups = tcpGroupChoices(c.servers)
 		} else {
-			selection.Groups = udpGroupChoices()
+			selection.Groups = udpGroupChoices(c.servers)
 		}
 	}
 
@@ -50,18 +50,18 @@ func (c *Cyberghost) filterServers(selection configuration.ServerSelection) (
 	return servers, nil
 }
 
-func tcpGroupChoices() (choices []string) {
+func tcpGroupChoices(servers []models.CyberghostServer) (choices []string) {
 	const tcp = true
-	return groupsForTCP(tcp)
+	return groupsForTCP(servers, tcp)
 }
 
-func udpGroupChoices() (choices []string) {
+func udpGroupChoices(servers []models.CyberghostServer) (choices []string) {
 	const tcp = false
-	return groupsForTCP(tcp)
+	return groupsForTCP(servers, tcp)
 }
 
-func groupsForTCP(tcp bool) (choices []string) {
-	allGroups := constants.CyberghostGroupChoices()
+func groupsForTCP(servers []models.CyberghostServer, tcp bool) (choices []string) {
+	allGroups := constants.CyberghostGroupChoices(servers)
 	choices = make([]string, 0, len(allGroups))
 	for _, group := range allGroups {
 		switch {

internal/provider/cyberghost/filter_test.go

@@ -21,7 +21,7 @@ func Test_Cyberghost_filterServers(t *testing.T) {
 	}{
 		"no server": {
 			selection: configuration.ServerSelection{VPN: constants.OpenVPN},
-			err:       errors.New("no server found: for VPN openvpn; protocol udp; groups Premium UDP Asia, Premium UDP Europe, Premium UDP USA"), //nolint:lll
+			err:       errors.New("no server found: for VPN openvpn; protocol udp"),
 		},
 		"servers without filter defaults to UDP": {
 			servers: []models.CyberghostServer{
@@ -146,10 +146,18 @@ func Test_Cyberghost_filterServers(t *testing.T) {
 func Test_tcpGroupChoices(t *testing.T) {
 	t.Parallel()
 
+	servers := []models.CyberghostServer{
+		{Group: "Premium TCP Asia"},
+		{Group: "Premium TCP Europe"},
+		{Group: "Premium TCP USA"},
+		{Group: "Premium UDP Asia"},
+		{Group: "Premium UDP Europe"},
+		{Group: "Premium UDP USA"},
+	}
 	expected := []string{
 		"Premium TCP Asia", "Premium TCP Europe", "Premium TCP USA",
 	}
-	choices := tcpGroupChoices()
+	choices := tcpGroupChoices(servers)
 
 	assert.Equal(t, expected, choices)
 }
@@ -157,10 +165,18 @@ func Test_tcpGroupChoices(t *testing.T) {
 func Test_udpGroupChoices(t *testing.T) {
 	t.Parallel()
 
+	servers := []models.CyberghostServer{
+		{Group: "Premium TCP Asia"},
+		{Group: "Premium TCP Europe"},
+		{Group: "Premium TCP USA"},
+		{Group: "Premium UDP Asia"},
+		{Group: "Premium UDP Europe"},
+		{Group: "Premium UDP USA"},
+	}
 	expected := []string{
 		"Premium UDP Asia", "Premium UDP Europe", "Premium UDP USA",
 	}
-	choices := udpGroupChoices()
+	choices := udpGroupChoices(servers)
 
 	assert.Equal(t, expected, choices)
 }

internal/provider/privateinternetaccess/portforward.go

@@ -33,7 +33,7 @@ var (
 func (p *PIA) PortForward(ctx context.Context, client *http.Client,
 	logger logging.Logger, gateway net.IP, serverName string) (
 	port uint16, err error) {
-	server := constants.PIAServerWhereName(serverName)
+	server := constants.PIAServerWhereName(p.servers, serverName)
 	if !server.PortForward {
 		logger.Error("The server " + serverName +
 			" (region " + server.Region + ") does not support port forwarding")