feat: add error handling when rpc is not connecting

avail_server.go

@@ -38,6 +38,7 @@ var ErrNotFound = errors.New("not found")
 const AvailByte = 0x0a
 
 func NewAvailDAServer(host string, port int, store AvailStore, log log.Logger, useGenericComm bool) *AvailDAServer {
+
 	endpoint := net.JoinHostPort(host, strconv.Itoa(port))
 	return &AvailDAServer{
 		log:      log,

service/avail_service.go

@@ -18,8 +18,8 @@ type AvailService struct {
 }
 
 func NewAvailService(apiURL string, seed string, appID int, timeout time.Duration) *AvailService {
-	availSpecs, err := types.NewAvailDASpecs(apiURL, appID, seed, timeout)
 
+	availSpecs, err := types.NewAvailDASpecs(apiURL, appID, seed, timeout)
 	if err != nil {
 		panic("failed avail initialisation")
 	}

types/avail_block_ref.go

@@ -49,8 +49,13 @@ type AvailDASpecs struct {
 }
 
 func NewAvailDASpecs(ApiURL string, AppID int, Seed string, Timeout time.Duration) (*AvailDASpecs, error) {
+
 	AppID = utils.EnsureValidAppID(AppID)
-	api, _ := utils.GetSubstrateApi(ApiURL)
+	api, err := utils.GetSubstrateApi(ApiURL)
+	if err != nil {
+		log.Error("⚠️ cannot connect to the rpc: error:%w", err)
+		return nil, err
+	}
 
 	meta, err := api.RPC.State.GetMetadataLatest()
 	if err != nil {

utils/utils.go

@@ -20,6 +20,7 @@ func GetAccountNonce(accountNonce uint32) uint32 {
 }
 
 func GetSubstrateApi(ApiURL string) (*gsrpc.SubstrateAPI, error) {
+
 	api, err := gsrpc.NewSubstrateAPI(ApiURL)
 
 	if err != nil {