Refactor table management to use a dedicated API and improve command handling.

family/type.go

@@ -1,18 +1,18 @@
-package nft
+package family
 
 import "fmt"
 
-type FamilyType int8
+type Type int8
 
 const (
-	IP FamilyType = iota + 1
+	IP Type = iota + 1
 	IP6
 	INET
 	ARP
 	BRIDGE
 )
 
-func (f FamilyType) String() string {
+func (f Type) String() string {
 	switch f {
 	case IP:
 		return "ip"

internal/command/command.go

@@ -0,0 +1,37 @@
+package command
+
+import (
+	"errors"
+	"os/exec"
+)
+
+type NFT interface {
+	Run(arg ...string) error
+}
+
+type execNFT struct {
+	nftPath string
+}
+
+func New(path string) (NFT, error) {
+	if err := checkingNFT(path); err != nil {
+		return nil, err
+	}
+
+	return &execNFT{
+		nftPath: path,
+	}, nil
+}
+
+func (r *execNFT) Run(arg ...string) error {
+	cmd := exec.Command(r.nftPath, arg...)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		if len(out) > 0 {
+			return errors.New(string(out))
+		}
+		return err
+	}
+
+	return nil
+}

internal/command/utils.go

@@ -1,4 +1,4 @@
-package nft
+package command
 
 import (
 	"errors"
@@ -8,19 +8,6 @@ import (
 	"strings"
 )
 
-func executeCommand(name string, arg ...string) error {
-	cmd := exec.Command(name, arg...)
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		if len(out) > 0 {
-			return errors.New(string(out))
-		}
-		return err
-	}
-
-	return nil
-}
-
 func checkingNFT(path string) error {
 	if path == "" {
 		return errors.New("path is empty")

internal/table/table.go

@@ -0,0 +1,51 @@
+package table
+
+import (
+	"git.kor-elf.net/kor-elf-shield/go-nftables-client/family"
+	"git.kor-elf.net/kor-elf-shield/go-nftables-client/internal/command"
+)
+
+type API 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
+}
+
+type table struct {
+	command command.NFT
+}
+
+func New(command command.NFT) API {
+	return &table{
+		command: command,
+	}
+}
+
+func (t *table) Add(family family.Type, tableName string) error {
+	args := []string{"add", "table", family.String(), tableName}
+	return t.command.Run(args...)
+}
+
+func (t *table) Delete(family family.Type, tableName string) error {
+	args := []string{"delete", "table", family.String(), tableName}
+	return t.command.Run(args...)
+}
+
+func (t *table) Clear(family family.Type, tableName string) error {
+	args := []string{"flush", "table", family.String(), tableName}
+	return t.command.Run(args...)
+}

nft.go

@@ -2,6 +2,9 @@ package nft
 
 import (
 	"errors"
+
+	"git.kor-elf.net/kor-elf-shield/go-nftables-client/internal/command"
+	"git.kor-elf.net/kor-elf-shield/go-nftables-client/internal/table"
 )
 
 // NFT A client for working with nftables
@@ -12,27 +15,13 @@ type NFT interface {
 	//    nft flush ruleset
 	Clear() error
 
-	// AddTable adds a new table.
+	// Table returns an API for working with tables.
-	//
+	Table() table.API
-	// This command is equivalent to:
-	//     nft add table (ip|ip6|inet|arp|bridge) {table_name}
-	AddTable(family FamilyType, tableName string) error
-
-	// DeleteTable deletes a table.
-	//
-	// This command is equivalent to:
-	//     nft delete table (ip|ip6|inet|arp|bridge) {table_name}
-	DeleteTable(family FamilyType, 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}
-	ClearTable(family FamilyType, tableName string) error
 }
 
 type nft struct {
-	path string
+	command command.NFT
+	table   table.API
 }
 
 // New Returns a client for working with nftables.
@@ -51,31 +40,22 @@ func New() (NFT, error) {
 
 // NewWithPath Returns the client for working with nftables with its path specified.
 func NewWithPath(path string) (NFT, error) {
-	if err := checkingNFT(path); err != nil {
+	nftCommand, err := command.New(path)
+	if err != nil {
 		return nil, err
 	}
 
 	return &nft{
-		path: path,
+		command: nftCommand,
+		table:   table.New(nftCommand),
 	}, nil
 }
 
 func (n *nft) Clear() error {
 	args := []string{"flush", "ruleset"}
-	return executeCommand(n.path, args...)
+	return n.command.Run(args...)
 }
 
-func (n *nft) AddTable(family FamilyType, tableName string) error {
+func (n *nft) Table() table.API {
-	args := []string{"add", "table", family.String(), tableName}
+	return n.table
-	return executeCommand(n.path, args...)
-}
-
-func (n *nft) DeleteTable(family FamilyType, tableName string) error {
-	args := []string{"delete", "table", family.String(), tableName}
-	return executeCommand(n.path, args...)
-}
-
-func (n *nft) ClearTable(family FamilyType, tableName string) error {
-	args := []string{"flush", "table", family.String(), tableName}
-	return executeCommand(n.path, args...)
 }