Add initial nftables client implementation

nft.go

@@ -0,0 +1,53 @@
+package nft
+
+import (
+	"errors"
+)
+
+// NFT A client for working with nftables
+type NFT interface {
+	// Clear clears all rules.
+	Clear() error
+
+	// AddTable adds a new table.
+	AddTable(family FamilyType, name string) error
+}
+
+type nft struct {
+	path string
+}
+
+// New Returns a client for working with nftables.
+// Searches for nft in paths: nft, /usr/sbin/nft, /sbin/nft
+func New() (NFT, error) {
+	paths := []string{"nft", "/usr/sbin/nft", "/sbin/nft"}
+	for _, path := range paths {
+		nftClient, err := NewWithPath(path)
+		if err == nil {
+			return nftClient, nil
+		}
+	}
+
+	return nil, errors.New("nft not found")
+}
+
+// NewWithPath Returns the client for working with nftables with its path specified.
+func NewWithPath(path string) (NFT, error) {
+	if err := checkingNFT(path); err != nil {
+		return nil, err
+	}
+
+	return &nft{
+		path: path,
+	}, nil
+}
+
+func (n *nft) Clear() error {
+	args := []string{"flush", "ruleset"}
+	return executeCommand(n.path, args...)
+}
+
+func (n *nft) AddTable(family FamilyType, name string) error {
+	args := []string{"add", "table", family.String(), name}
+	return executeCommand(n.path, args...)
+}