Merge pull request 'feature-10' (#16) from feature-10 into main

Reviewed-on: #16

.forgejo/workflows/prerelease.yml

@@ -32,7 +32,12 @@ jobs:
       matrix:
         goos: [linux]
         goarch: [amd64]
-        binaries: [db, metadata, metacli, agent]
+        binaries:
+          - db
+          - metadata
+          - metacli
+          - agent
+          - netns
     uses: ./.forgejo/workflows/build.yml
     with:
       tag: ${{ needs.set-release-target.outputs.release_cible }}

cmd/netns/main.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"git.g3e.fr/syonad/two/internal/netns"
+)
+
+var (
+	netns_name = flag.String("netns", "", "Network namespace à faire")
+	action     = flag.String("action", "", "Action a faire")
+)
+
+func main() {
+	flag.Parse()
+
+	switch *action {
+	case "create":
+		err := netns.Create(*netns_name)
+		if err != nil {
+			fmt.Println(err)
+		}
+	case "delete":
+		err := netns.Delete(*netns_name)
+		if err != nil {
+			fmt.Println(err)
+		}
+	case "check":
+		if netns.Exist(*netns_name) {
+			fmt.Printf("netns %s exist\n", *netns_name)
+		} else {
+			fmt.Printf("netns %s do not exist\n", *netns_name)
+		}
+	default:
+		fmt.Printf("Available commande:\n - create\n - delete\n - check\n")
+		os.Exit(1)
+	}
+}

internal/netns/call.go

@@ -0,0 +1,5 @@
+package netns
+
+func Call(name string, fn func() error) error {
+	return call(name, fn)
+}

internal/netns/call_linux.go

@@ -0,0 +1,44 @@
+//go:build linux
+
+package netns
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+
+	"golang.org/x/sys/unix"
+)
+
+func call(name string, fn func() error) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	// sauvegarde du netns courant
+	orig, err := os.Open("/proc/self/ns/net")
+	if err != nil {
+		return err
+	}
+	defer orig.Close()
+
+	// entrer dans le netns cible
+	f, err := os.Open(fmt.Sprintf("/var/run/netns/%s", name))
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	if err := unix.Setns(int(f.Fd()), unix.CLONE_NEWNET); err != nil {
+		return err
+	}
+
+	// exécuter la fonction dans le netns
+	err = fn()
+
+	// toujours revenir au netns d'origine
+	if restoreErr := unix.Setns(int(orig.Fd()), unix.CLONE_NEWNET); restoreErr != nil {
+		return restoreErr
+	}
+
+	return err
+}

internal/netns/call_other.go

@@ -0,0 +1,7 @@
+//go:build !linux
+
+package netns
+
+func call(name string, fn func() error) error {
+	return fn()
+}

internal/netns/create.go

@@ -0,0 +1,5 @@
+package netns
+
+func Create(name string) error {
+	return create(name)
+}

internal/netns/create_linux.go

@@ -0,0 +1,55 @@
+//go:build linux
+
+package netns
+
+import (
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+func create(name string) error {
+	base := "/var/run/netns"
+	path := base + "/" + name
+
+	if err := os.MkdirAll(base, 0755); err != nil {
+		return err
+	}
+
+	// fichier cible
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	f.Close()
+
+	// sauvegarde du netns courant
+	orig, err := os.Open("/proc/self/ns/net")
+	if err != nil {
+		return err
+	}
+	defer orig.Close()
+
+	// nouveau netns
+	if err := unix.Unshare(unix.CLONE_NEWNET); err != nil {
+		return err
+	}
+
+	// bind mount du netns courant vers /var/run/netns/<name>
+	if err := unix.Mount(
+		"/proc/self/ns/net",
+		path,
+		"",
+		unix.MS_BIND,
+		"",
+	); err != nil {
+		return err
+	}
+
+	// revenir au netns original
+	if err := unix.Setns(int(orig.Fd()), unix.CLONE_NEWNET); err != nil {
+		return err
+	}
+
+	return nil
+}

internal/netns/create_other.go

@@ -0,0 +1,5 @@
+//go:build !linux
+
+package netns
+
+func create(string) error { return nil }

internal/netns/delete.go

@@ -0,0 +1,5 @@
+package netns
+
+func Delete(name string) error {
+	return delete(name)
+}

internal/netns/delete_linux.go

@@ -0,0 +1,18 @@
+//go:build linux
+
+package netns
+
+import (
+	"os"
+
+	"golang.org/x/sys/unix"
+)
+
+func delete(name string) error {
+	path := "/var/run/netns/" + name
+
+	if err := unix.Unmount(path, unix.MNT_DETACH); err != nil {
+		return err
+	}
+	return os.Remove(path)
+}

internal/netns/delete_other.go

@@ -0,0 +1,5 @@
+//go:build !linux
+
+package netns
+
+func delete(string) error { return nil }

internal/netns/exist.go

@@ -0,0 +1,14 @@
+package netns
+
+import (
+	"os"
+)
+
+func exist(name string) bool {
+	_, err := os.Stat("/var/run/netns/" + name)
+	return err == nil
+}
+
+func Exist(name string) bool {
+	return exist(name)
+}