f-25: vms: add iptables gestion

Signed-off-by: GnomeZworc <nicolas.boufidjeline@g3e.fr>

internal/iptables/iptables.go

@@ -0,0 +1,42 @@
+package iptables
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+func addRule(args ...string) error {
+	return exec.Command("iptables", append([]string{"-t", "nat", "-A"}, args...)...).Run()
+}
+
+func deleteRule(args ...string) error {
+	return exec.Command("iptables", append([]string{"-t", "nat", "-D"}, args...)...).Run()
+}
+
+func AddMetadataRedirect(vmIP, gatewayIP, metadataPort string) error {
+	if err := addRule("PREROUTING",
+		"-s", vmIP+"/32",
+		"-d", "169.254.169.254/32",
+		"-p", "tcp", "-m", "tcp",
+		"--dport", "80",
+		"-j", "DNAT",
+		"--to-destination", gatewayIP+":"+metadataPort,
+	); err != nil {
+		return fmt.Errorf("iptables metadata redirect: %w", err)
+	}
+	return nil
+}
+
+func DeleteMetadataRedirect(vmIP, gatewayIP, metadataPort string) error {
+	if err := deleteRule("PREROUTING",
+		"-s", vmIP+"/32",
+		"-d", "169.254.169.254/32",
+		"-p", "tcp", "-m", "tcp",
+		"--dport", "80",
+		"-j", "DNAT",
+		"--to-destination", gatewayIP+":"+metadataPort,
+	); err != nil {
+		return fmt.Errorf("iptables delete metadata redirect: %w", err)
+	}
+	return nil
+}