[client] Add embeddable library

[lixmal]

Describe your changes

• Add embed package
• Fix default routes for netstack
• Fix DNS for netstack

Example listen program:

package main

import (
	"context"
	"errors"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	netbird "github.com/netbirdio/netbird/client/embed"
)

func main() {
	// Create client with setup key and device name
	client, err := netbird.New(netbird.Options{
		DeviceName:    "http-server",
		SetupKey:      os.Getenv("NB_SETUP_KEY"),
		ManagementURL: os.Getenv("NB_MANAGEMENT_URL"),
		LogOutput:     io.Discard,
	})
	if err != nil {
		log.Fatal(err)
	}

	// Start with timeout
	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
	defer cancel()

	if err := client.Start(ctx); err != nil {
		log.Fatal(err)
	}

	// Create HTTP server
	mux := http.NewServeMux()
	mux.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
		fmt.Printf("Request from %s: %s %s\n", r.RemoteAddr, r.Method, r.URL.Path)
		fmt.Fprintf(w, "Hello from netbird!")
	})

	// Listen on netbird network
	l, err := client.ListenTCP(":8080")
	if err != nil {
		log.Fatal(err)
	}

	server := &http.Server{Handler: mux}
	go func() {
		if err := server.Serve(l); !errors.Is(err, http.ErrServerClosed) {
			log.Printf("HTTP server error: %v", err)
		}
	}()

	log.Printf("HTTP server listening on netbird network port 8080")

	// Handle shutdown
	stop := make(chan os.Signal, 1)
	signal.Notify(stop, syscall.SIGINT, syscall.SIGTERM)
	<-stop

	shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	if err := server.Shutdown(shutdownCtx); err != nil {
		log.Printf("HTTP shutdown error: %v", err)
	}

	if err := client.Stop(shutdownCtx); err != nil {
		log.Printf("Netbird shutdown error: %v", err)
	}
}

Run:

go mod init nbembed
go mod edit -replace=golang.zx2c4.com/wireguard=github.com/netbirdio/[email protected]
go mod edit -replace=github.com/cloudflare/circl=github.com/cunicu/[email protected]
go mod edit -replace=github.com/pion/ice/v3=github.com/netbirdio/ice/[email protected]
go get github.com/netbirdio/netbird@embed-netbird
go mod tidy

NB_SETUP_KEY=xxx  go run .

Issue ticket number and link

Checklist

• Is it a bug fix
• Is a typo/documentation fix
• Is a feature enhancement
• It is a refactor
• Created tests that fail without the change (if possible)
• Extended the README / documentation, if necessary

[pappz]

I recommend creating a doc file in the embed package with your example code.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud