feat(vpn): VPN_ENDPOINT_IP

- Deprecate `OPENVPN_TARGET_IP`
- Deprecate `WIREGUARD_ENDPOINT_IP`

Dockerfile

@@ -68,6 +68,8 @@ LABEL \
     org.opencontainers.image.description="VPN swiss-knife like client to tunnel to multiple VPN servers using OpenVPN, IPtables, DNS over TLS, Shadowsocks, an HTTP proxy and Alpine Linux"
 ENV VPNSP=pia \
     VPN_TYPE=openvpn \
+    # Common VPN options
+    VPN_ENDPOINT_IP= \
     # OpenVPN
     OPENVPN_PROTOCOL=udp \
     OPENVPN_USER= \
@@ -80,7 +82,6 @@ ENV VPNSP=pia \
     OPENVPN_CIPHER= \
     OPENVPN_AUTH= \
     OPENVPN_PROCESS_USER= \
-    OPENVPN_TARGET_IP= \
     OPENVPN_IPV6=off \
     OPENVPN_CUSTOM_CONFIG= \
     OPENVPN_INTERFACE=tun0 \
@@ -90,7 +91,6 @@ ENV VPNSP=pia \
     WIREGUARD_PRESHARED_KEY= \
     WIREGUARD_PUBLIC_KEY= \
     WIREGUARD_ADDRESS= \
-    WIREGUARD_ENDPOINT_IP= \
     WIREGUARD_ENDPOINT_PORT= \
     WIREGUARD_INTERFACE=wg0 \
     # VPN server filtering

internal/configuration/sources/env/serverselection.go

@@ -20,7 +20,7 @@ func (r *Reader) readServerSelection(vpnProvider, vpnType string) (
 	ss settings.ServerSelection, err error) {
 	ss.VPN = vpnType
 
-	ss.TargetIP, err = readOpenVPNTargetIP()
+	ss.TargetIP, err = r.readOpenVPNTargetIP()
 	if err != nil {
 		return ss, err
 	}
@@ -99,16 +99,23 @@ var (
 	ErrInvalidIP = errors.New("invalid IP address")
 )
 
-func readOpenVPNTargetIP() (ip net.IP, err error) {
-	s := os.Getenv("OPENVPN_TARGET_IP")
+func (r *Reader) readOpenVPNTargetIP() (ip net.IP, err error) {
+	envKey := "OPENVPN_TARGET_IP"
+	s := os.Getenv(envKey) // Retro-compatibility
 	if s == "" {
-		return nil, nil
+		envKey = "VPN_ENDPOINT_IP"
+		s = os.Getenv(envKey)
+		if s == "" {
+			return nil, nil
+		}
+	} else {
+		r.onRetroActive("OPENVPN_TARGET_IP", "VPN_ENDPOINT_IP")
 	}
 
 	ip = net.ParseIP(s)
 	if ip == nil {
-		return nil, fmt.Errorf("environment variable OPENVPN_TARGET_IP: %w: %s",
-			ErrInvalidIP, s)
+		return nil, fmt.Errorf("environment variable %s: %w: %s",
+			envKey, ErrInvalidIP, s)
 	}
 
 	return ip, nil

internal/configuration/sources/env/wireguardselection.go

@@ -12,7 +12,7 @@ import (
 
 func (r *Reader) readWireguardSelection() (
 	selection settings.WireguardSelection, err error) {
-	selection.EndpointIP, err = readWireguardEndpointIP()
+	selection.EndpointIP, err = r.readWireguardEndpointIP()
 	if err != nil {
 		return selection, err
 	}
@@ -29,16 +29,28 @@ func (r *Reader) readWireguardSelection() (
 
 var ErrIPAddressParse = errors.New("cannot parse IP address")
 
-func readWireguardEndpointIP() (endpointIP net.IP, err error) {
-	s := os.Getenv("WIREGUARD_ENDPOINT_IP")
+func (r *Reader) readWireguardEndpointIP() (endpointIP net.IP, err error) {
+	const currentKey = "VPN_ENDPOINT_IP"
+	key := "WIREGUARD_ENDPOINT_IP"
+	s := os.Getenv(key) // Retro-compatibility
 	if s == "" {
-		return nil, nil
+		key = currentKey
+		s = os.Getenv(key)
+		if s == "" {
+			return nil, nil
+		}
 	}
+
+	if key != currentKey {
+		r.onRetroActive(key, currentKey)
+	}
+
 	endpointIP = net.ParseIP(s)
 	if endpointIP == nil {
-		return nil, fmt.Errorf("environment variable WIREGUARD_ENDPOINT_IP: %w: %s",
-			ErrIPAddressParse, s)
+		return nil, fmt.Errorf("environment variable %s: %w: %s",
+			key, ErrIPAddressParse, s)
 	}
+
 	return endpointIP, nil
 }