//import cfg_opt "github.com/haproxytech/client-native/v4/configuration/options"
confClient, err := configuration.New(context.Background(),
    cfg_opt.ConfigurationFile(haproxyOptions.ConfigFile),
    cfg_opt.HAProxyBin(haproxyOptions.HAProxy),
    cfg_opt.Backups(haproxyOptions.BackupsNumber),
    cfg_opt.UsePersistentTransactions,
    cfg_opt.TransactionsDir(haproxyOptions.TransactionDir),
    cfg_opt.MasterWorker,
    cfg_opt.UseMd5Hash,
)
if err != nil {
    return nil, fmt.Errorf("error setting up configuration client: %s", err.Error())
}

// runtime
// import runtime_options "github.com/haproxytech/client-native/v4/runtime/options"
nbproc := 8
ms := runtime_options.MasterSocket(masterSocket, nbproc)
runtimeClient, err = runtime_api.New(ctx, ms)
if err != nil {
    return nil, fmt.Errorf("error setting up runtime client: %s", err.Error())
}
// or if not using master-worker
socketList := map[int]string{
    1: "/var/run/haproxy.sock"
}
sockets := runtime_options.Sockets(socketList)
runtimeClient, err = runtime_api.New(ctx, mapsDir, sockets)
if err != nil {
    return nil, fmt.Errorf("error setting up runtime client: %s", err.Error())
}
// end runtime

// import "github.com/haproxytech/client-native/v4/options"
opt := []options.Option{
    options.Configuration(confClient),
    options.Runtime(runtimeClient),
}

// aditional options - not mandatory

//maps storage
mapStorage, err := storage.New(MapsDir, storage.MapsType)
if err != nil {
    log.Fatalf("error initializing map storage: %v", err)
}
opt = append(opt, options.MapStorage(mapStorage))

//ssl cert storage
sslCertStorage, err := storage.New(SSLCertsDir, storage.SSLType)
if err != nil {
    log.Fatalf("error initializing SSL certs storage: %v", err)
}
opt = append(opt, options.SSLCertStorage(sslCertStorage))

// general storage
generalStorage, err := storage.New(GeneralStorage, storage.GeneralType)
if err != nil {
    log.Fatalf("error initializing General storage: %v", err)
}
opt = append(opt, options.GeneralStorage(generalStorage))

//spoe
prms := spoe.Params{
    SpoeDir:        SpoeDir,
    TransactionDir: SpoeTransactionDir,
}
spoe, err := spoe.NewSpoe(prms)
if err != nil {
    log.Fatalf("error setting up spoe: %v", err)
}
opt = append(opt, options.Spoe(spoe))

// combine all together and create a client
client, err := client_native.New(cyx, opt...)
if err != nil {
    log.Fatalf("Error initializing configuration client: %v", err)
}

// fetch configuration handler
configuration, err := client.Configuration()
if err != nil {
    fmt.Println(err.Error())
}

//fetch all backends
bcks, err := configuration.GetBackends(t)
if err != nil {
    fmt.Println(err.Error())
}
//...

backendsJSON, err := bcks.MarshallBinary()

if err != nil {
    fmt.Println(err.Error())
}

fmt.Println(string(backendsJSON))
//...