feat: move L2 dial logic out of bss-core

This avoids having l2geth as a dependency for other projects building on
bss-core. Speicifically this avoids having to copy l2geth into docker
builds.

.changeset/poor-walls-do.md

+---
+'@eth-optimism/batch-submitter-service': patch
+---
+
+Move L2 dial logic out of bss-core to avoid l2geth dependency

go/batch-submitter/batch_submitter.go

@@ -93,7 +93,7 @@ func Main(gitVersion string) func(ctx *cli.Context) error {
 			return err
 		}
 
-		l2Client, err := dial.L2EthClientWithTimeout(ctx, cfg.L2EthRpc, cfg.DisableHTTP2)
+		l2Client, err := DialL2EthClientWithTimeout(ctx, cfg.L2EthRpc, cfg.DisableHTTP2)
 		if err != nil {
 			return err
 		}

go/bss-core/dial/l2_client.go → go/batch-submitter/dial_l2_client.go

-package dial
+package batchsubmitter
 
 import (
 	"context"
@@ -6,18 +6,19 @@ import (
 	"net/http"
 	"strings"
 
+	"github.com/ethereum-optimism/optimism/go/bss-core/dial"
 	"github.com/ethereum-optimism/optimism/l2geth/ethclient"
 	"github.com/ethereum-optimism/optimism/l2geth/log"
 	"github.com/ethereum-optimism/optimism/l2geth/rpc"
 )
 
-// L2EthClientWithTimeout attempts to dial the L2 provider using the
-// provided URL. If the dial doesn't complete within defaultDialTimeout seconds,
+// DialL2EthClientWithTimeout attempts to dial the L2 provider using the
+// provided URL. If the dial doesn't complete within dial.DefaultTimeout seconds,
 // this method will return an error.
-func L2EthClientWithTimeout(ctx context.Context, url string, disableHTTP2 bool) (
+func DialL2EthClientWithTimeout(ctx context.Context, url string, disableHTTP2 bool) (
 	*ethclient.Client, error) {
 
-	ctxt, cancel := context.WithTimeout(ctx, defaultDialTimeout)
+	ctxt, cancel := context.WithTimeout(ctx, dial.DefaultTimeout)
 	defer cancel()
 
 	if strings.HasPrefix(url, "http") {

go/bss-core/dial/common.go

@@ -3,7 +3,7 @@ package dial
 import "time"
 
 const (
-	// defaultDialTimeout is default duration the service will wait on
-	// startup to make a connection to either the L1 or L2 backends.
-	defaultDialTimeout = 5 * time.Second
+	// DefaultTimeout is default duration the service will wait on startup to
+	// make a connection to either the L1 or L2 backends.
+	DefaultTimeout = 5 * time.Second
 )

go/bss-core/dial/l1_client.go

@@ -12,12 +12,12 @@ import (
 )
 
 // L1EthClientWithTimeout attempts to dial the L1 provider using the
-// provided URL. If the dial doesn't complete within defaultDialTimeout seconds,
+// provided URL. If the dial doesn't complete within DefaultTimeout seconds,
 // this method will return an error.
 func L1EthClientWithTimeout(ctx context.Context, url string, disableHTTP2 bool) (
 	*ethclient.Client, error) {
 
-	ctxt, cancel := context.WithTimeout(ctx, defaultDialTimeout)
+	ctxt, cancel := context.WithTimeout(ctx, DefaultTimeout)
 	defer cancel()
 
 	if strings.HasPrefix(url, "http") {

go/bss-core/go.mod

@@ -3,13 +3,11 @@ module github.com/ethereum-optimism/optimism/go/bss-core
 go 1.16
 
 require (
+	github.com/btcsuite/btcd v0.22.0-beta // indirect
 	github.com/decred/dcrd/hdkeychain/v3 v3.0.0
-	github.com/ethereum-optimism/optimism/l2geth v1.0.0
 	github.com/ethereum/go-ethereum v1.10.12
 	github.com/getsentry/sentry-go v0.11.0
 	github.com/prometheus/client_golang v1.11.0
 	github.com/stretchr/testify v1.7.0
 	github.com/tyler-smith/go-bip39 v1.0.1-0.20181017060643-dbb3b84ba2ef
 )
-
-replace github.com/ethereum-optimism/optimism/l2geth => ../../l2geth