Refactor to consolidate APIs into contract package and introduce NFT interface for better modularity and maintainability.

contract/command.go

@@ -0,0 +1,12 @@
+package contract
+
+// Run is a function that executes nft command.
+type Run func(arg ...string) error
+
+type Command interface {
+	// Run nft command.
+	Run(arg ...string) error
+
+	// RunWithOutput Run nft command with output.
+	RunWithOutput(arg ...string) (string, error)
+}

contract/nft.go

@@ -0,0 +1,31 @@
+package contract
+
+import "git.kor-elf.net/kor-elf-shield/go-nftables-client/contract/nft"
+
+// NFT A client for working with nftables
+type NFT interface {
+	// Command returns the command used to execute nft.
+	// You can execute your raw request.
+	Command() Command
+
+	// Clear clears all rules.
+	//
+	// This command is equivalent to:
+	//    nft flush ruleset
+	Clear() error
+
+	// Version returns the version of nftables.
+	//
+	// This command is equivalent to:
+	//    nft -V
+	Version() (nft.Version, error)
+
+	// Table returns an API for working with tables.
+	Table() nft.Table
+
+	// Chain returns an API for working with chains.
+	Chain() nft.Chain
+
+	// Rule returns an API for working with rules.
+	Rule() nft.Rule
+}

contract/nft/chain.go

@@ -0,0 +1,46 @@
+package nft
+
+import (
+	chain2 "git.kor-elf.net/kor-elf-shield/go-nftables-client/chain"
+	"git.kor-elf.net/kor-elf-shield/go-nftables-client/family"
+)
+
+// Chain for working with chains.
+type Chain interface {
+	// Add adds a new chain.
+	//
+	// This command is equivalent to:
+	//     nft add chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name}
+	//     nft add chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ type (filter|route|nat) hook (ingress|prerouting|forward|input|output|postrouting|egress) priority (priority_value = int32) ;}'
+	//     nft add chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ type filter hook (forward|input|output) priority (priority_value = int32) ; policy (accept|drop) ;}'
+	//     nft add chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ type (filter|route|nat) hook (ingress|egress) device {device} priority (priority_value = int32) ;}'
+	Add(family family.Type, tableName string, chainName string, baseChain chain2.ChainOptions) error
+
+	// Create creates a new chain.
+	// Similar to the Add, but returns an error if the chain already exists.
+	//
+	// This command is equivalent to:
+	//     nft create chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name}
+	//     nft create chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ type (filter|route|nat) hook (ingress|prerouting|forward|input|output|postrouting|egress) priority (priority_value = int32) ;}'
+	//     nft create chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ type filter hook (forward|input|output) priority (priority_value = int32) ; policy (accept|drop) ;}'
+	//     nft create chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ type (filter|route|nat) hook (ingress|egress) device {device} priority (priority_value = int32) ;}'
+	Create(family family.Type, tableName string, chainName string, baseChain chain2.ChainOptions) error
+
+	// Delete deletes a chain.
+	//
+	// This command is equivalent to:
+	//     nft delete chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name}
+	Delete(family family.Type, tableName string, chainName string) error
+
+	// Clear clears all rules in a chain.
+	//
+	// This command is equivalent to:
+	//     nft flush chain (ip|ip6|inet|arp|bridge) {table_name} {chain_name}
+	Clear(family family.Type, tableName string, chainName string) error
+
+	// Rename renames a chain.
+	//
+	// This command is equivalent to:
+	//     nft rename chain (ip|ip6|inet|arp|bridge) {table_name} {old_chain_name} {new_chain_name}
+	Rename(family family.Type, tableName string, oldChainName string, newChainName string) error
+}

contract/nft/rule.go

@@ -0,0 +1,31 @@
+package nft
+
+import "git.kor-elf.net/kor-elf-shield/go-nftables-client/family"
+
+// Rule is the interface for rule manipulation.
+type Rule interface {
+	// Add adds a new rule.
+	//
+	// This command is equivalent to:
+	// 		nft add rule (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ expr }'
+	Add(family family.Type, tableName string, chainName string, expr ...string) error
+
+	// Insert inserts a new rule.
+	// Inserted rules are placed at the beginning of the chain, by default.
+	//
+	// This command is equivalent to:
+	// 		nft insert rule (ip|ip6|inet|arp|bridge) {table_name} {chain_name} '{ expr }'
+	Insert(family family.Type, tableName string, chainName string, expr ...string) error
+
+	// Replace replaces a rule.
+	//
+	// This command is equivalent to:
+	// 		nft replace rule (ip|ip6|inet|arp|bridge) {table_name} {chain_name} {handle} '{ expr }'
+	Replace(family family.Type, tableName string, chainName string, handle uint64, expr ...string) error
+
+	// Delete deletes a rule.
+	//
+	// This command is equivalent to:
+	// 		nft delete rule (ip|ip6|inet|arp|bridge) {table_name} {chain_name} {handle}
+	Delete(family family.Type, tableName string, chainName string, handle uint64) error
+}

contract/nft/table.go

@@ -0,0 +1,24 @@
+package nft
+
+import "git.kor-elf.net/kor-elf-shield/go-nftables-client/family"
+
+// Table for working with tables.
+type Table interface {
+	// AddTable adds a new table.
+	//
+	// This command is equivalent to:
+	//     nft add table (ip|ip6|inet|arp|bridge) {table_name}
+	Add(family family.Type, tableName string) error
+
+	// DeleteTable deletes a table.
+	//
+	// This command is equivalent to:
+	//     nft delete table (ip|ip6|inet|arp|bridge) {table_name}
+	Delete(family family.Type, tableName string) error
+
+	// ClearTable clears all rules in a table.
+	//
+	// This command is equivalent to:
+	//     nft flush table (ip|ip6|inet|arp|bridge) {table_name}
+	Clear(family family.Type, tableName string) error
+}

contract/nft/version.go

@@ -0,0 +1,8 @@
+package nft
+
+type Version interface {
+	// Version returns the version of the nftables client.
+	Version() string
+	// Opts returns the options of the nftables client.
+	Opts() map[string]string
+}