feat(healthcheck): combination of ICMP and TCP+TLS checks (#2923)

- New option: `HEALTH_ICMP_TARGET_IP` defaults to `0.0.0.0` meaning use the VPN server public IP address.
- Options removed: `HEALTH_VPN_INITIAL_DURATION` and `HEALTH_VPN_ADDITIONAL_DURATION` - times and retries are handpicked and hardcoded.
- Less aggressive checks and less false positive detection

internal/vpn/openvpn.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/qdm12/gluetun/internal/configuration/settings"
+	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/openvpn"
 	"github.com/qdm12/gluetun/internal/provider"
 )
@@ -14,39 +15,38 @@ import (
 func setupOpenVPN(ctx context.Context, fw Firewall,
 	openvpnConf OpenVPN, providerConf provider.Provider,
 	settings settings.VPN, ipv6Supported bool, starter CmdStarter,
-	logger openvpn.Logger) (runner *openvpn.Runner, serverName string,
-	canPortForward bool, err error,
+	logger openvpn.Logger) (runner *openvpn.Runner, connection models.Connection, err error,
 ) {
-	connection, err := providerConf.GetConnection(settings.Provider.ServerSelection, ipv6Supported)
+	connection, err = providerConf.GetConnection(settings.Provider.ServerSelection, ipv6Supported)
 	if err != nil {
-		return nil, "", false, fmt.Errorf("finding a valid server connection: %w", err)
+		return nil, models.Connection{}, fmt.Errorf("finding a valid server connection: %w", err)
 	}
 
 	lines := providerConf.OpenVPNConfig(connection, settings.OpenVPN, ipv6Supported)
 
 	if err := openvpnConf.WriteConfig(lines); err != nil {
-		return nil, "", false, fmt.Errorf("writing configuration to file: %w", err)
+		return nil, models.Connection{}, fmt.Errorf("writing configuration to file: %w", err)
 	}
 
 	if *settings.OpenVPN.User != "" {
 		err := openvpnConf.WriteAuthFile(*settings.OpenVPN.User, *settings.OpenVPN.Password)
 		if err != nil {
-			return nil, "", false, fmt.Errorf("writing auth to file: %w", err)
+			return nil, models.Connection{}, fmt.Errorf("writing auth to file: %w", err)
 		}
 	}
 
 	if *settings.OpenVPN.KeyPassphrase != "" {
 		err := openvpnConf.WriteAskPassFile(*settings.OpenVPN.KeyPassphrase)
 		if err != nil {
-			return nil, "", false, fmt.Errorf("writing askpass file: %w", err)
+			return nil, models.Connection{}, fmt.Errorf("writing askpass file: %w", err)
 		}
 	}
 
 	if err := fw.SetVPNConnection(ctx, connection, settings.OpenVPN.Interface); err != nil {
-		return nil, "", false, fmt.Errorf("allowing VPN connection through firewall: %w", err)
+		return nil, models.Connection{}, fmt.Errorf("allowing VPN connection through firewall: %w", err)
 	}
 
 	runner = openvpn.NewRunner(settings.OpenVPN, starter, logger)
 
-	return runner, connection.ServerName, connection.PortForward, nil
+	return runner, connection, nil
 }