initial nftables config generation test

pkg/definitions/config.go

@@ -0,0 +1,6 @@
+package definitions
+
+type Config struct {
+	ConfigVersion int64     `json:"config_version"`
+	Netfilter     Netfilter `json:"netfilter"`
+}

pkg/definitions/netfilter.go

@@ -0,0 +1,7 @@
+package definitions
+
+type Netfilter struct {
+	ForwardRules        []ForwardRule        `json:"forward_rules"`
+	DestinationNATRules []DestinationNATRule `json:"destination_nat_rules"`
+	SourceNATRules      []SourceNATRule      `json:"source_nat_rules"`
+}

pkg/definitions/rules.go

@@ -0,0 +1,23 @@
+package definitions
+
+type Rule struct {
+	Match   RuleMatch `json:"match"`
+	Comment string    `json:"comment"`
+	Counter bool      `json:"counter"`
+}
+
+type RuleMatch struct {
+	TCPDestinationPort uint64 `json:"tcp_destination_port"`
+}
+
+type ForwardRule struct {
+	Rule
+}
+
+type DestinationNATRule struct {
+	Rule
+}
+
+type SourceNATRule struct {
+	Rule
+}