Retrocompatiblity with EXTRA_SUBNETS key

internal/params/params.go

@@ -159,3 +159,10 @@ func (r *reader) GetVPNSP() (vpnServiceProvider models.VPNProvider, err error) {
 func (r *reader) GetVersionInformation() (enabled bool, err error) {
 	return r.envParams.GetOnOff("VERSION_INFORMATION", libparams.Default("on"))
 }
+
+func (r *reader) onRetroActive(oldKey, newKey string) {
+	r.logger.Warn(
+		"You are using the old environment variable %s, please consider changing it to %s",
+		oldKey, newKey,
+	)
+}

internal/params/routing.go

@@ -4,13 +4,19 @@ import (
 	"fmt"
 	"net"
 	"strings"
+
+	libparams "github.com/qdm12/golibs/params"
 )
 
 // GetOutboundSubnets obtains the CIDR subnets from the comma separated list of the
 // environment variable FIREWALL_OUTBOUND_SUBNETS.
 func (r *reader) GetOutboundSubnets() (outboundSubnets []net.IPNet, err error) {
 	const key = "FIREWALL_OUTBOUND_SUBNETS"
-	s, err := r.envParams.GetEnv(key)
+	retroOption := libparams.RetroKeys(
+		[]string{"EXTRA_SUBNETS"},
+		r.onRetroActive,
+	)
+	s, err := r.envParams.GetEnv(key, retroOption)
 	if err != nil {
 		return nil, err
 	} else if s == "" {