Add default firewall rules and fix tests in the github flow.

client/internal/firewall_linux.go

@@ -0,0 +1,18 @@
+package internal
+
+import (
+	log "github.com/sirupsen/logrus"
+
+	"github.com/netbirdio/netbird/client/firewall"
+	"github.com/netbirdio/netbird/client/firewall/iptables"
+)
+
+// buildFirewallManager creates a firewall manager instance for the Linux
+func buildFirewallManager(wgIfaceName string) (firewall.Manager, error) {
+	fw, err := iptables.Create(wgIfaceName)
+	if err != nil {
+		log.Debugf("failed to create iptables manager: %s", err)
+		return nil, err
+	}
+	return fw, nil
+}