feat: indexer-retry substrate node connection

cmd/indexer/commands/substrate.go

@@ -2,7 +2,9 @@ package commands
 
 import (
 	"context"
+	"fmt"
 
+	"github.com/cenkalti/backoff"
 	"github.com/jmoiron/sqlx"
 	"github.com/mailchain/mailchain/cmd/indexer/internal/processor"
 	sub "github.com/mailchain/mailchain/cmd/indexer/internal/substrate"
@@ -22,7 +24,6 @@ func substrateCmd() *cobra.Command {
 		TraverseChildren: true,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			network := viper.GetString("network")
-			println(network)
 			protocol := viper.GetString("protocol")
 			blockNumber := viper.GetString("start_block")
 			maxRetries := viper.GetUint64("max_retries")
@@ -50,7 +51,23 @@ func substrateCmd() *cobra.Command {
 			defer connPublicKey.Close()
 			defer connEnvelope.Close()
 
-			seqProcessor, err := createSubstrateProcessor(connIndexer, connPublicKey, connEnvelope, blockNumber, protocol, network, addressRPC)
+			var subClient *sub.BlockClient
+			operation := func() error {
+				var err error
+				subClient, err = sub.NewRPC(addressRPC)
+				if err != nil {
+					fmt.Fprintf(cmd.ErrOrStderr(), "%+v\n", err)
+				}
+
+				return err
+			}
+
+			if err := backoff.Retry(operation, backoff.WithMaxRetries(backoff.NewExponentialBackOff(), 3)); err != nil {
+				fmt.Fprintf(cmd.ErrOrStderr(), "Number of retries has reached to %d. Exiting.\\n", 3)
+				return err
+			}
+
+			seqProcessor, err := createSubstrateProcessor(subClient, connIndexer, connPublicKey, connEnvelope, blockNumber, protocol, network)
 			if err != nil {
 				return err
 			}
@@ -73,15 +90,10 @@ func substrateCmd() *cobra.Command {
 	return cmd
 }
 
-func createSubstrateProcessor(connIndexer, connPublicKey, connEnvelope *sqlx.DB, blockNumber, protocol, network, addressRPC string) (*processor.Sequential, error) {
+func createSubstrateProcessor(client *sub.BlockClient, connIndexer, connPublicKey, connEnvelope *sqlx.DB, blockNumber, protocol, network string) (*processor.Sequential, error) {
 	ctx := context.Background()
 
-	subClient, err := sub.NewRPC(addressRPC)
-	if err != nil {
-		return nil, err
-	}
-
-	blockNo, err := getBlockNumber(blockNumber, subClient)
+	blockNo, err := getBlockNumber(blockNumber, client)
 	if err != nil {
 		return nil, err
 	}
@@ -117,6 +129,6 @@ func createSubstrateProcessor(connIndexer, connPublicKey, connEnvelope *sqlx.DB,
 		network,
 		syncStore,
 		sub.NewBlockProcessor(processorTransaction),
-		subClient,
+		client,
 	), nil
 }