From 0f3b9e90174b6d1e9ab673bb423b3bc35342ba58 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Mon, 21 Feb 2022 14:23:07 -0700
Subject: [PATCH 01/12] initial commit and some questions

---
 cmd/peggo/bridge.go       | 20 ++++++++------------
 cmd/peggo/flags.go        |  4 ++++
 cmd/peggo/grpcclient.go   | 31 +++++++++++++++++++++++++++++++
 cmd/peggo/orchestrator.go |  2 ++
 4 files changed, 45 insertions(+), 12 deletions(-)
 create mode 100644 cmd/peggo/grpcclient.go

diff --git a/cmd/peggo/bridge.go b/cmd/peggo/bridge.go
index 0315a9bb..d058e04a 100644
--- a/cmd/peggo/bridge.go
+++ b/cmd/peggo/bridge.go
@@ -113,10 +113,9 @@ func deployGravityCmd() *cobra.Command {
 			}
 
 			// ETH RPC
-			ethRPCEndpoint := konfig.String(flagEthRPC)
-			ethRPC, err := ethclient.Dial(ethRPCEndpoint)
+			ethRPC, err := getEthClient(konfig)
 			if err != nil {
-				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
+				return err
 			}
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
@@ -194,10 +193,9 @@ func deployERC20Cmd() *cobra.Command {
 				return err
 			}
 
-			ethRPCEndpoint := konfig.String(flagEthRPC)
-			ethRPC, err := ethclient.Dial(ethRPCEndpoint)
+			ethRPC, err := getEthClient(konfig)
 			if err != nil {
-				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
+				return err
 			}
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
@@ -329,10 +327,9 @@ network starting.`,
 				return err
 			}
 
-			ethRPCEndpoint := konfig.String(flagEthRPC)
-			ethRPC, err := ethclient.Dial(ethRPCEndpoint)
+			ethRPC, err := getEthClient(konfig)
 			if err != nil {
-				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
+				return err
 			}
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
@@ -391,10 +388,9 @@ func sendToCosmosCmd() *cobra.Command {
 				return err
 			}
 
-			ethRPCEndpoint := konfig.String(flagEthRPC)
-			ethRPC, err := ethclient.Dial(ethRPCEndpoint)
+			ethRPC, err := getEthClient(konfig)
 			if err != nil {
-				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
+				return err
 			}
 
 			gravityAddr := args[0]
diff --git a/cmd/peggo/flags.go b/cmd/peggo/flags.go
index 3f92b1c1..e64120dc 100644
--- a/cmd/peggo/flags.go
+++ b/cmd/peggo/flags.go
@@ -2,6 +2,8 @@
 package peggo
 
 import (
+	"fmt"
+
 	"github.com/cosmos/cosmos-sdk/crypto/keyring"
 	"github.com/spf13/pflag"
 )
@@ -32,6 +34,7 @@ const (
 	flagEthPK                   = "eth-pk"
 	flagEthUseLedger            = "eth-use-ledger"
 	flagEthRPC                  = "eth-rpc"
+	flagEthRPCs                 = "eth-rpcs"
 	flagEthGasAdjustment        = "eth-gas-price-adjustment"
 	flagEthGasLimitAdjustment   = "eth-gas-limit-adjustment"
 	flagEthAlchemyWS            = "eth-alchemy-ws"
@@ -93,6 +96,7 @@ func ethereumOptsFlagSet() *pflag.FlagSet {
 	fs.String(flagEthRPC, "http://localhost:8545", "Specify the RPC address of an Ethereum node")
 	fs.Float64(flagEthGasAdjustment, float64(1.3), "Specify a gas price adjustment for Ethereum transactions")
 	fs.Float64(flagEthGasLimitAdjustment, float64(1.2), "Specify a gas limit adjustment for Ethereum transactions")
+	_ = fs.MarkDeprecated(flagEthRPC, fmt.Sprintf("Use the '%s' flag instead to provide one or more Ethereum RPC instances", flagEthRPCs))
 
 	return fs
 }
diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
new file mode 100644
index 00000000..46a2896c
--- /dev/null
+++ b/cmd/peggo/grpcclient.go
@@ -0,0 +1,31 @@
+package peggo
+
+import (
+	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/knadh/koanf"
+	"github.com/pkg/errors"
+)
+
+// dials configured ethereum rpc endpoints, returning a client connected to the first successfully dialed
+func getEthClient(konfig *koanf.Koanf) (*ethclient.Client, error) {
+	rpcs := konfig.Strings(flagEthRPCs)
+
+	for _, endpoint := range rpcs {
+		if cli, err := ethclient.Dial(endpoint); err == nil {
+			return cli, nil
+		}
+	}
+
+	// todo #196: this doesn't try to remember if an endpoint is failing frequently
+	// which would be needed to rotate / avoid trying to dial it every single time.
+	//
+	// a cheap way to do basically that would be to store the last endpoint *successfully*
+	// dialed using a var at the top of this file, always trying that first if non-empty,
+	// clearing it on fail, and setting it to a new string whenever a dial succeeds on
+	// an endpoint in the for loop
+	//
+	// also, if there are other reasons we want to avoid an endpoint (e.g. dialing succeeds
+	// but the rpcs are behaving badly) then this function won't be able to help
+
+	return nil, errors.New("Could not connect to any of the Ethereum RPC endpoints provided")
+}
diff --git a/cmd/peggo/orchestrator.go b/cmd/peggo/orchestrator.go
index b8f1e8c7..76e8650e 100644
--- a/cmd/peggo/orchestrator.go
+++ b/cmd/peggo/orchestrator.go
@@ -116,6 +116,8 @@ func getOrchestratorCmd() *cobra.Command {
 				return fmt.Errorf("failed to initialize Ethereum account: %w", err)
 			}
 
+			// todo #196: change this to try multiple endpoints. Also, is this one more complicated
+			// than the other cmds, i.e. the client is being reused over time?
 			ethRPCEndpoint := konfig.String(flagEthRPC)
 			ethRPC, err := ethrpc.Dial(ethRPCEndpoint)
 			if err != nil {

From 0a18552a6891106e811aabb436ef8a9014b14f0d Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Mon, 21 Feb 2022 14:48:26 -0700
Subject: [PATCH 02/12] flags updates

---
 cmd/peggo/flags.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/cmd/peggo/flags.go b/cmd/peggo/flags.go
index c5d4b2f8..0040248c 100644
--- a/cmd/peggo/flags.go
+++ b/cmd/peggo/flags.go
@@ -91,6 +91,7 @@ func ethereumOptsFlagSet() *pflag.FlagSet {
 	fs := pflag.NewFlagSet("", pflag.ContinueOnError)
 
 	fs.String(flagEthRPC, "http://localhost:8545", "Specify the RPC address of an Ethereum node")
+	fs.StringSlice(flagEthRPCs, []string{"http://localhost:8545"}, "Specify RPC addresses of one or more Ethereum nodes")
 	fs.Float64(flagEthGasAdjustment, float64(1.3), "Specify a gas price adjustment for Ethereum transactions")
 	fs.Float64(flagEthGasLimitAdjustment, float64(1.2), "Specify a gas limit adjustment for Ethereum transactions")
 	_ = fs.MarkDeprecated(flagEthRPC, fmt.Sprintf("Use the '%s' flag instead to provide one or more Ethereum RPC instances", flagEthRPCs))
@@ -102,8 +103,10 @@ func bridgeFlagSet() *pflag.FlagSet {
 	fs := pflag.NewFlagSet("", pflag.ContinueOnError)
 
 	fs.String(flagEthRPC, "http://localhost:8545", "Specify the RPC address of an Ethereum node")
+	fs.StringSlice(flagEthRPCs, []string{"http://localhost:8545"}, "Specify RPC addresses of one or more Ethereum nodes")
 	fs.Int64(flagEthGasPrice, 0, "The Ethereum gas price to include in the transaction; If zero, gas price will be estimated")
 	fs.Int64(flagEthGasLimit, 6000000, "The Ethereum gas limit to include in the transaction")
+	_ = fs.MarkDeprecated(flagEthRPC, fmt.Sprintf("Use the '%s' flag instead to provide one or more Ethereum RPC instances", flagEthRPCs))
 
 	return fs
 }

From c105f8973750fd2d078156c5d9cd9e8b125480a6 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Mon, 21 Feb 2022 14:49:45 -0700
Subject: [PATCH 03/12] lint++

---
 cmd/peggo/grpcclient.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index 46a2896c..c4184726 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -27,5 +27,5 @@ func getEthClient(konfig *koanf.Koanf) (*ethclient.Client, error) {
 	// also, if there are other reasons we want to avoid an endpoint (e.g. dialing succeeds
 	// but the rpcs are behaving badly) then this function won't be able to help
 
-	return nil, errors.New("Could not connect to any of the Ethereum RPC endpoints provided")
+	return nil, errors.New("could not connect to any of the Ethereum RPC endpoints provided")
 }

From 79f54544162d9277b0adb158730f1e115be8e278 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Tue, 22 Feb 2022 08:31:18 -0700
Subject: [PATCH 04/12] current progress

---
 cmd/peggo/bridge.go       | 21 ++++-------
 cmd/peggo/grpcclient.go   | 77 ++++++++++++++++++++++++++++++---------
 cmd/peggo/orchestrator.go |  1 +
 cmd/peggo/peggo.go        |  2 +-
 4 files changed, 69 insertions(+), 32 deletions(-)

diff --git a/cmd/peggo/bridge.go b/cmd/peggo/bridge.go
index d058e04a..66ab9d16 100644
--- a/cmd/peggo/bridge.go
+++ b/cmd/peggo/bridge.go
@@ -113,7 +113,8 @@ func deployGravityCmd() *cobra.Command {
 			}
 
 			// ETH RPC
-			ethRPC, err := getEthClient(konfig)
+			InitEthRPCManager(konfig)
+			ethRPC, err := ethManager.GetClient()
 			if err != nil {
 				return err
 			}
@@ -193,10 +194,8 @@ func deployERC20Cmd() *cobra.Command {
 				return err
 			}
 
-			ethRPC, err := getEthClient(konfig)
-			if err != nil {
-				return err
-			}
+			InitEthRPCManager(konfig)
+			ethRPC, err := ethManager.GetClient()
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
 			if err != nil {
@@ -327,10 +326,8 @@ network starting.`,
 				return err
 			}
 
-			ethRPC, err := getEthClient(konfig)
-			if err != nil {
-				return err
-			}
+			InitEthRPCManager(konfig)
+			ethRPC, err := ethManager.GetClient()
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
 			if err != nil {
@@ -388,10 +385,8 @@ func sendToCosmosCmd() *cobra.Command {
 				return err
 			}
 
-			ethRPC, err := getEthClient(konfig)
-			if err != nil {
-				return err
-			}
+			InitEthRPCManager(konfig)
+			ethRPC, err := ethManager.GetClient()
 
 			gravityAddr := args[0]
 
diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index c4184726..54a369f3 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -6,26 +6,67 @@ import (
 	"github.com/pkg/errors"
 )
 
-// dials configured ethereum rpc endpoints, returning a client connected to the first successfully dialed
-func getEthClient(konfig *koanf.Koanf) (*ethclient.Client, error) {
-	rpcs := konfig.Strings(flagEthRPCs)
+var ethManager *EthRPCManager
 
-	for _, endpoint := range rpcs {
-		if cli, err := ethclient.Dial(endpoint); err == nil {
-			return cli, nil
+type EthRPCManager struct {
+	currentEndpoint int               // the slice index of the endpoint currently used
+	client          *ethclient.Client // the current client
+	konfig          *koanf.Koanf
+
+	// TODO: how to detect client failures so we can call DialNext()
+	// maybe wrap methods
+}
+
+// initializes the single instance of EthRPCManager with a given config (uses flagEthRPCs)
+func InitEthRPCManager(konfig *koanf.Koanf) {
+	if ethManager == nil {
+		ethManager = &EthRPCManager{
+			konfig: konfig,
+		}
+	}
+}
+
+// closes the current client and dials configured ethereum rpc endpoints in a roundrobin fashion until one
+// is connected. returns an error if no endpoints exist or all dials failed
+func (em *EthRPCManager) DialNext() error {
+	rpcs := em.konfig.Strings(flagEthRPCs)
+
+	if em.client != nil {
+		em.client.Close()
+		em.client = nil
+	}
+
+	dialIndex := func(i int) bool {
+		if cli, err := ethclient.Dial(rpcs[i]); err == nil {
+			em.currentEndpoint = i
+			em.client = cli
+			return true
 		}
+		return false
 	}
 
-	// todo #196: this doesn't try to remember if an endpoint is failing frequently
-	// which would be needed to rotate / avoid trying to dial it every single time.
-	//
-	// a cheap way to do basically that would be to store the last endpoint *successfully*
-	// dialed using a var at the top of this file, always trying that first if non-empty,
-	// clearing it on fail, and setting it to a new string whenever a dial succeeds on
-	// an endpoint in the for loop
-	//
-	// also, if there are other reasons we want to avoid an endpoint (e.g. dialing succeeds
-	// but the rpcs are behaving badly) then this function won't be able to help
-
-	return nil, errors.New("could not connect to any of the Ethereum RPC endpoints provided")
+	// first tries all endpoints in the slice after the current index
+	for i := range rpcs {
+		if i > em.currentEndpoint && dialIndex(i) {
+			return nil
+		}
+	}
+
+	// then tries remaining endpoints from the beginning of the slice
+	for i := range rpcs {
+		if i <= em.currentEndpoint && dialIndex(i) {
+			return nil
+		}
+	}
+
+	return errors.New("could not dial any of the Ethereum RPC endpoints provided")
+}
+
+func (em *EthRPCManager) GetClient() (*ethclient.Client, error) {
+	if em.client == nil {
+		if err := em.DialNext(); err != nil {
+			return nil, err
+		}
+	}
+	return em.client, nil
 }
diff --git a/cmd/peggo/orchestrator.go b/cmd/peggo/orchestrator.go
index 1bac8d3e..463aac52 100644
--- a/cmd/peggo/orchestrator.go
+++ b/cmd/peggo/orchestrator.go
@@ -120,6 +120,7 @@ func getOrchestratorCmd() *cobra.Command {
 			// than the other cmds, i.e. the client is being reused over time?
 			ethRPCEndpoint := konfig.String(flagEthRPC)
 			ethRPC, err := ethrpc.Dial(ethRPCEndpoint)
+			//ethRPC, err := ethManager.GetClient() // todo: wrong type. find out why.
 			if err != nil {
 				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
 			}
diff --git a/cmd/peggo/peggo.go b/cmd/peggo/peggo.go
index 58612cc8..a72108b9 100644
--- a/cmd/peggo/peggo.go
+++ b/cmd/peggo/peggo.go
@@ -21,7 +21,7 @@ func NewRootCmd() *cobra.Command {
 		Long: `Peggo is a companion executable for orchestrating a Gravity validator.
 
 Inputs in the CLI commands can be provided via flags or environment variables. If
-using the later, prefix the environment variable with PEGGO_ and the named of the
+using the latter, prefix the environment variable with PEGGO_ and the named of the
 flag (e.g. PEGGO_COSMOS_PK).`,
 	}
 

From bb1609f5c97fe22a66dd01ef3e21749a3adf74e1 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Tue, 22 Feb 2022 09:20:30 -0700
Subject: [PATCH 05/12] resolved a type issue

---
 cmd/peggo/bridge.go       |  8 ++++----
 cmd/peggo/grpcclient.go   | 20 +++++++++++++++-----
 cmd/peggo/orchestrator.go |  8 +++-----
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/cmd/peggo/bridge.go b/cmd/peggo/bridge.go
index 66ab9d16..eed14279 100644
--- a/cmd/peggo/bridge.go
+++ b/cmd/peggo/bridge.go
@@ -114,7 +114,7 @@ func deployGravityCmd() *cobra.Command {
 
 			// ETH RPC
 			InitEthRPCManager(konfig)
-			ethRPC, err := ethManager.GetClient()
+			ethRPC, err := ethManager.GetEthClient()
 			if err != nil {
 				return err
 			}
@@ -195,7 +195,7 @@ func deployERC20Cmd() *cobra.Command {
 			}
 
 			InitEthRPCManager(konfig)
-			ethRPC, err := ethManager.GetClient()
+			ethRPC, err := ethManager.GetEthClient()
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
 			if err != nil {
@@ -327,7 +327,7 @@ network starting.`,
 			}
 
 			InitEthRPCManager(konfig)
-			ethRPC, err := ethManager.GetClient()
+			ethRPC, err := ethManager.GetEthClient()
 
 			auth, err := buildTransactOpts(konfig, ethRPC)
 			if err != nil {
@@ -386,7 +386,7 @@ func sendToCosmosCmd() *cobra.Command {
 			}
 
 			InitEthRPCManager(konfig)
-			ethRPC, err := ethManager.GetClient()
+			ethRPC, err := ethManager.GetEthClient()
 
 			gravityAddr := args[0]
 
diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index 54a369f3..48a13b19 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -2,6 +2,7 @@ package peggo
 
 import (
 	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/knadh/koanf"
 	"github.com/pkg/errors"
 )
@@ -9,9 +10,10 @@ import (
 var ethManager *EthRPCManager
 
 type EthRPCManager struct {
-	currentEndpoint int               // the slice index of the endpoint currently used
-	client          *ethclient.Client // the current client
-	konfig          *koanf.Koanf
+	currentEndpoint int // the slice index of the endpoint currently used
+	//client          *ethclient.Client // the current client
+	client *rpc.Client
+	konfig *koanf.Koanf
 
 	// TODO: how to detect client failures so we can call DialNext()
 	// maybe wrap methods
@@ -37,7 +39,7 @@ func (em *EthRPCManager) DialNext() error {
 	}
 
 	dialIndex := func(i int) bool {
-		if cli, err := ethclient.Dial(rpcs[i]); err == nil {
+		if cli, err := rpc.Dial(rpcs[i]); err == nil {
 			em.currentEndpoint = i
 			em.client = cli
 			return true
@@ -62,7 +64,7 @@ func (em *EthRPCManager) DialNext() error {
 	return errors.New("could not dial any of the Ethereum RPC endpoints provided")
 }
 
-func (em *EthRPCManager) GetClient() (*ethclient.Client, error) {
+func (em *EthRPCManager) GetClient() (*rpc.Client, error) {
 	if em.client == nil {
 		if err := em.DialNext(); err != nil {
 			return nil, err
@@ -70,3 +72,11 @@ func (em *EthRPCManager) GetClient() (*ethclient.Client, error) {
 	}
 	return em.client, nil
 }
+
+func (em *EthRPCManager) GetEthClient() (*ethclient.Client, error) {
+	cli, err := em.GetClient()
+	if err != nil {
+		return nil, err
+	}
+	return ethclient.NewClient(cli), nil
+}
diff --git a/cmd/peggo/orchestrator.go b/cmd/peggo/orchestrator.go
index 463aac52..f82317c8 100644
--- a/cmd/peggo/orchestrator.go
+++ b/cmd/peggo/orchestrator.go
@@ -11,7 +11,6 @@ import (
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	ethcmn "github.com/ethereum/go-ethereum/common"
-	ethrpc "github.com/ethereum/go-ethereum/rpc"
 	"github.com/rs/zerolog"
 	"github.com/spf13/cobra"
 	rpchttp "github.com/tendermint/tendermint/rpc/client/http"
@@ -118,14 +117,13 @@ func getOrchestratorCmd() *cobra.Command {
 
 			// todo #196: change this to try multiple endpoints. Also, is this one more complicated
 			// than the other cmds, i.e. the client is being reused over time?
-			ethRPCEndpoint := konfig.String(flagEthRPC)
-			ethRPC, err := ethrpc.Dial(ethRPCEndpoint)
-			//ethRPC, err := ethManager.GetClient() // todo: wrong type. find out why.
+			// ethRPCEndpoint := konfig.String(flagEthRPC)
+			ethRPC, err := ethManager.GetClient()
 			if err != nil {
 				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
 			}
 
-			fmt.Fprintf(os.Stderr, "Connected to Ethereum RPC: %s\n", ethRPCEndpoint)
+			//fmt.Fprintf(os.Stderr, "Connected to Ethereum RPC: %s\n", ethRPCEndpoint)
 			ethProvider := provider.NewEVMProvider(ethRPC)
 
 			ethGasPriceAdjustment := konfig.Float64(flagEthGasAdjustment)

From 6dc4898c8a0576aee4926eba4c24b4397fcbf600 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Tue, 22 Feb 2022 10:32:25 -0700
Subject: [PATCH 06/12] comments

---
 cmd/peggo/grpcclient.go | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index 48a13b19..93efa6d9 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -1,6 +1,8 @@
 package peggo
 
 import (
+	"fmt"
+
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/knadh/koanf"
@@ -28,15 +30,20 @@ func InitEthRPCManager(konfig *koanf.Koanf) {
 	}
 }
 
-// closes the current client and dials configured ethereum rpc endpoints in a roundrobin fashion until one
-// is connected. returns an error if no endpoints exist or all dials failed
-func (em *EthRPCManager) DialNext() error {
-	rpcs := em.konfig.Strings(flagEthRPCs)
-
+// closes and sets to nil the stored eth RPC client
+func (em *EthRPCManager) CloseClient() {
 	if em.client != nil {
 		em.client.Close()
 		em.client = nil
 	}
+}
+
+// closes the current client and dials configured ethereum rpc endpoints in a roundrobin fashion until one
+// is connected. returns an error if no endpoints ar configured or all dials failed
+func (em *EthRPCManager) DialNext() error {
+	rpcs := em.konfig.Strings(flagEthRPCs)
+
+	em.CloseClient()
 
 	dialIndex := func(i int) bool {
 		if cli, err := rpc.Dial(rpcs[i]); err == nil {
@@ -44,6 +51,7 @@ func (em *EthRPCManager) DialNext() error {
 			em.client = cli
 			return true
 		}
+		// todo: should likely log the error
 		return false
 	}
 
@@ -61,9 +69,10 @@ func (em *EthRPCManager) DialNext() error {
 		}
 	}
 
-	return errors.New("could not dial any of the Ethereum RPC endpoints provided")
+	return errors.New(fmt.Sprintf("could not dial any of the %d Ethereum RPC endpoints configured", len(rpcs)))
 }
 
+// returns the current eth RPC client, dialing one first if nonexistent
 func (em *EthRPCManager) GetClient() (*rpc.Client, error) {
 	if em.client == nil {
 		if err := em.DialNext(); err != nil {
@@ -73,6 +82,7 @@ func (em *EthRPCManager) GetClient() (*rpc.Client, error) {
 	return em.client, nil
 }
 
+// returns the current eth RPC client, dialing one first if nonexistent
 func (em *EthRPCManager) GetEthClient() (*ethclient.Client, error) {
 	cli, err := em.GetClient()
 	if err != nil {

From 77894acd1b44389dc0050dfd9e2d299ed8c6f3b0 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Wed, 23 Feb 2022 18:17:04 -0700
Subject: [PATCH 07/12] comments

---
 cmd/peggo/orchestrator.go | 4 ----
 cmd/peggo/peggo.go        | 2 +-
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/cmd/peggo/orchestrator.go b/cmd/peggo/orchestrator.go
index dd50e293..e631cb3a 100644
--- a/cmd/peggo/orchestrator.go
+++ b/cmd/peggo/orchestrator.go
@@ -122,15 +122,11 @@ func getOrchestratorCmd() *cobra.Command {
 				return fmt.Errorf("failed to initialize Ethereum account: %w", err)
 			}
 
-			// todo #196: change this to try multiple endpoints. Also, is this one more complicated
-			// than the other cmds, i.e. the client is being reused over time?
-			// ethRPCEndpoint := konfig.String(flagEthRPC)
 			ethRPC, err := ethManager.GetClient()
 			if err != nil {
 				return fmt.Errorf("failed to dial Ethereum RPC node: %w", err)
 			}
 
-			//fmt.Fprintf(os.Stderr, "Connected to Ethereum RPC: %s\n", ethRPCEndpoint)
 			ethProvider := provider.NewEVMProvider(ethRPC)
 
 			ethGasPriceAdjustment := konfig.Float64(flagEthGasAdjustment)
diff --git a/cmd/peggo/peggo.go b/cmd/peggo/peggo.go
index a72108b9..a9cf8da9 100644
--- a/cmd/peggo/peggo.go
+++ b/cmd/peggo/peggo.go
@@ -81,7 +81,7 @@ func parseServerConfig(cmd *cobra.Command) (*koanf.Koanf, error) {
 	konfig := koanf.New(".")
 
 	// load from file first (if provided)
-	// TODO: Support config files if/when needed.
+	// TODO: Support config files if/when needed. Koanf also supports watch the config file for changes
 	// if configPath := ctx.String(config.ConfigPath); len(configPath) != 0 {
 	// 	if err := konfig.Load(file.Provider(configPath), toml.Parser()); err != nil {
 	// 		return nil, err

From 34c97e0c26e50eede2cb0e430733f4e2f149f6bd Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Wed, 23 Feb 2022 19:50:42 -0700
Subject: [PATCH 08/12] simple functions wrapped

---
 cmd/peggo/bridge.go     | 20 ++++++++--------
 cmd/peggo/grpcclient.go | 51 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 61 insertions(+), 10 deletions(-)

diff --git a/cmd/peggo/bridge.go b/cmd/peggo/bridge.go
index b9fd3d9c..98cacd08 100644
--- a/cmd/peggo/bridge.go
+++ b/cmd/peggo/bridge.go
@@ -125,7 +125,7 @@ func deployGravityCmd() *cobra.Command {
 				return err
 			}
 
-			auth, err := buildTransactOpts(konfig, ethRPC)
+			auth, err := buildTransactOpts(konfig)
 			if err != nil {
 				return err
 			}
@@ -203,7 +203,7 @@ func deployERC20Cmd() *cobra.Command {
 			InitEthRPCManager(konfig)
 			ethRPC, err := ethManager.GetEthClient()
 
-			auth, err := buildTransactOpts(konfig, ethRPC)
+			auth, err := buildTransactOpts(konfig)
 			if err != nil {
 				return err
 			}
@@ -341,7 +341,7 @@ network starting.`,
 			InitEthRPCManager(konfig)
 			ethRPC, err := ethManager.GetEthClient()
 
-			auth, err := buildTransactOpts(konfig, ethRPC)
+			auth, err := buildTransactOpts(konfig)
 			if err != nil {
 				return err
 			}
@@ -416,7 +416,7 @@ func sendToCosmosCmd() *cobra.Command {
 				}
 			}
 
-			auth, err := buildTransactOpts(konfig, ethRPC)
+			auth, err := buildTransactOpts(konfig)
 			if err != nil {
 				return err
 			}
@@ -459,7 +459,9 @@ Transaction: %s
 	return cmd
 }
 
-func buildTransactOpts(konfig *koanf.Koanf, ethClient *ethclient.Client) (*bind.TransactOpts, error) {
+func buildTransactOpts(konfig *koanf.Koanf) (*bind.TransactOpts, error) {
+	InitEthRPCManager(konfig)
+
 	ethPrivKeyHexStr := konfig.String(flagEthPK)
 
 	privKey, err := ethcrypto.ToECDSA(ethcmn.FromHex(ethPrivKeyHexStr))
@@ -478,7 +480,7 @@ func buildTransactOpts(konfig *koanf.Koanf, ethClient *ethclient.Client) (*bind.
 
 	fromAddress := ethcrypto.PubkeyToAddress(*publicKeyECDSA)
 
-	nonce, err := ethClient.PendingNonceAt(goCtx, fromAddress)
+	nonce, err := ethManager.PendingNonceAt(goCtx, fromAddress)
 	if err != nil {
 		return nil, err
 	}
@@ -486,7 +488,7 @@ func buildTransactOpts(konfig *koanf.Koanf, ethClient *ethclient.Client) (*bind.
 	goCtx, cancel = context.WithTimeout(context.Background(), 15*time.Second)
 	defer cancel()
 
-	ethChainID, err := ethClient.ChainID(goCtx)
+	ethChainID, err := ethManager.ChainID(goCtx)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get Ethereum chain ID: %w", err)
 	}
@@ -507,7 +509,7 @@ func buildTransactOpts(konfig *koanf.Koanf, ethClient *ethclient.Client) (*bind.
 		gasPrice = big.NewInt(gasPriceInt)
 
 	default:
-		gasPrice, err = ethClient.SuggestGasPrice(context.Background())
+		gasPrice, err = ethManager.SuggestGasPrice(context.Background())
 		if err != nil {
 			return nil, fmt.Errorf("failed to get Ethereum gas estimate: %w", err)
 		}
@@ -555,7 +557,7 @@ func approveERC20(konfig *koanf.Koanf, ethRPC *ethclient.Client, erc20AddrStr, g
 		return fmt.Errorf("failed to create ERC20 contract instance: %w", err)
 	}
 
-	auth, err := buildTransactOpts(konfig, ethRPC)
+	auth, err := buildTransactOpts(konfig)
 	if err != nil {
 		return err
 	}
diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index 93efa6d9..aa110144 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -1,8 +1,11 @@
 package peggo
 
 import (
+	"context"
 	"fmt"
+	"math/big"
 
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/knadh/koanf"
@@ -21,7 +24,8 @@ type EthRPCManager struct {
 	// maybe wrap methods
 }
 
-// initializes the single instance of EthRPCManager with a given config (uses flagEthRPCs)
+// initializes the single instance of EthRPCManager with a given config (uses flagEthRPCs).
+// no-op if already initialized, even if konfig would be different.
 func InitEthRPCManager(konfig *koanf.Koanf) {
 	if ethManager == nil {
 		ethManager = &EthRPCManager{
@@ -41,6 +45,9 @@ func (em *EthRPCManager) CloseClient() {
 // closes the current client and dials configured ethereum rpc endpoints in a roundrobin fashion until one
 // is connected. returns an error if no endpoints ar configured or all dials failed
 func (em *EthRPCManager) DialNext() error {
+	if em.konfig == nil {
+		return errors.New("ethRPCManager konfig is nil")
+	}
 	rpcs := em.konfig.Strings(flagEthRPCs)
 
 	em.CloseClient()
@@ -90,3 +97,45 @@ func (em *EthRPCManager) GetEthClient() (*ethclient.Client, error) {
 	}
 	return ethclient.NewClient(cli), nil
 }
+
+// wraps ethclient.PendingNonceAt, also closing client if PendingNonceAt returns an error
+func (em *EthRPCManager) PendingNonceAt(ctx context.Context, addr common.Address) (uint64, error) {
+	cli, err := em.GetEthClient()
+	if err != nil {
+		return 0, err
+	}
+	nonce, err := cli.PendingNonceAt(ctx, addr)
+	if err != nil {
+		em.CloseClient()
+		return 0, err
+	}
+	return nonce, nil
+}
+
+// wraps ethclient.ChainID, also closing client if ChainID returns an error
+func (em *EthRPCManager) ChainID(ctx context.Context) (*big.Int, error) {
+	cli, err := em.GetEthClient()
+	if err != nil {
+		return nil, err
+	}
+	id, err := cli.ChainID(ctx)
+	if err != nil {
+		em.CloseClient()
+		return nil, err
+	}
+	return id, nil
+}
+
+// wraps ethclient.SuggestGasPrice, also closing client if SuggestGasPrice returns an error
+func (em *EthRPCManager) SuggestGasPrice(ctx context.Context) (*big.Int, error) {
+	cli, err := em.GetEthClient()
+	if err != nil {
+		return nil, err
+	}
+	price, err := cli.SuggestGasPrice(ctx)
+	if err != nil {
+		em.CloseClient()
+		return nil, err
+	}
+	return price, nil
+}

From 767e958cb519511ceed84985188d1829b0969084 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Wed, 23 Feb 2022 19:55:49 -0700
Subject: [PATCH 09/12] lint++

---
 cmd/peggo/bridge.go     | 9 +++++++++
 cmd/peggo/grpcclient.go | 8 ++------
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/cmd/peggo/bridge.go b/cmd/peggo/bridge.go
index 98cacd08..930ff418 100644
--- a/cmd/peggo/bridge.go
+++ b/cmd/peggo/bridge.go
@@ -202,6 +202,9 @@ func deployERC20Cmd() *cobra.Command {
 
 			InitEthRPCManager(konfig)
 			ethRPC, err := ethManager.GetEthClient()
+			if err != nil {
+				return err
+			}
 
 			auth, err := buildTransactOpts(konfig)
 			if err != nil {
@@ -340,6 +343,9 @@ network starting.`,
 
 			InitEthRPCManager(konfig)
 			ethRPC, err := ethManager.GetEthClient()
+			if err != nil {
+				return err
+			}
 
 			auth, err := buildTransactOpts(konfig)
 			if err != nil {
@@ -399,6 +405,9 @@ func sendToCosmosCmd() *cobra.Command {
 
 			InitEthRPCManager(konfig)
 			ethRPC, err := ethManager.GetEthClient()
+			if err != nil {
+				return err
+			}
 
 			gravityAddr := args[0]
 
diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index aa110144..4038b084 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -16,12 +16,8 @@ var ethManager *EthRPCManager
 
 type EthRPCManager struct {
 	currentEndpoint int // the slice index of the endpoint currently used
-	//client          *ethclient.Client // the current client
-	client *rpc.Client
-	konfig *koanf.Koanf
-
-	// TODO: how to detect client failures so we can call DialNext()
-	// maybe wrap methods
+	client          *rpc.Client
+	konfig          *koanf.Koanf
 }
 
 // initializes the single instance of EthRPCManager with a given config (uses flagEthRPCs).

From 70915db3bda09e873249583ea18ea12d8ef6242f Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Wed, 23 Feb 2022 20:05:29 -0700
Subject: [PATCH 10/12] e2e flag change

---
 test/e2e/e2e_setup_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/e2e/e2e_setup_test.go b/test/e2e/e2e_setup_test.go
index e0c1ed1e..1be6031c 100644
--- a/test/e2e/e2e_setup_test.go
+++ b/test/e2e/e2e_setup_test.go
@@ -545,7 +545,7 @@ func (s *IntegrationTestSuite) runContractDeployment() {
 				"peggo",
 				"bridge",
 				"deploy-gravity",
-				"--eth-rpc",
+				"--eth-rpcs",
 				fmt.Sprintf("http://%s:8545", s.ethResource.Container.Name[1:]),
 				"--cosmos-grpc",
 				fmt.Sprintf("tcp://%s:9090", s.valResources[0].Container.Name[1:]),

From 354a1df1e1a44dd38a8ac3925f7cd19a7938bab6 Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Wed, 23 Feb 2022 21:41:13 -0700
Subject: [PATCH 11/12] troubleshoot flag

---
 cmd/peggo/grpcclient.go    | 3 ++-
 test/e2e/e2e_setup_test.go | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index 4038b084..9be086da 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -44,7 +44,8 @@ func (em *EthRPCManager) DialNext() error {
 	if em.konfig == nil {
 		return errors.New("ethRPCManager konfig is nil")
 	}
-	rpcs := em.konfig.Strings(flagEthRPCs)
+	//rpcs := em.konfig.Strings(flagEthRPCs)
+	rpcs := []string{em.konfig.String(flagEthRPC)}
 
 	em.CloseClient()
 
diff --git a/test/e2e/e2e_setup_test.go b/test/e2e/e2e_setup_test.go
index 1be6031c..e0c1ed1e 100644
--- a/test/e2e/e2e_setup_test.go
+++ b/test/e2e/e2e_setup_test.go
@@ -545,7 +545,7 @@ func (s *IntegrationTestSuite) runContractDeployment() {
 				"peggo",
 				"bridge",
 				"deploy-gravity",
-				"--eth-rpcs",
+				"--eth-rpc",
 				fmt.Sprintf("http://%s:8545", s.ethResource.Container.Name[1:]),
 				"--cosmos-grpc",
 				fmt.Sprintf("tcp://%s:9090", s.valResources[0].Container.Name[1:]),

From ec3a6c5c3b4784476e404af4c0eb71396a5ec53a Mon Sep 17 00:00:00 2001
From: toteki <63419657+toteki@users.noreply.github.com>
Date: Wed, 23 Feb 2022 22:07:57 -0700
Subject: [PATCH 12/12] switch to comma-separated ethRPCs flag

---
 cmd/peggo/flags.go         | 2 +-
 cmd/peggo/grpcclient.go    | 5 +++--
 test/e2e/e2e_setup_test.go | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/cmd/peggo/flags.go b/cmd/peggo/flags.go
index 622a9022..97032baa 100644
--- a/cmd/peggo/flags.go
+++ b/cmd/peggo/flags.go
@@ -107,7 +107,7 @@ func bridgeFlagSet() *pflag.FlagSet {
 	fs := pflag.NewFlagSet("", pflag.ContinueOnError)
 
 	fs.String(flagEthRPC, "http://localhost:8545", "Specify the RPC address of an Ethereum node")
-	fs.StringSlice(flagEthRPCs, []string{"http://localhost:8545"}, "Specify RPC addresses of one or more Ethereum nodes")
+	fs.String(flagEthRPCs, "http://localhost:8545", "Specify comma-separated RPC addresses of one or more Ethereum nodes")
 	fs.Int64(flagEthGasPrice, 0, "The Ethereum gas price to include in the transaction; If zero, gas price will be estimated")
 	fs.Int64(flagEthGasLimit, 6000000, "The Ethereum gas limit to include in the transaction")
 	_ = fs.MarkDeprecated(flagEthRPC, fmt.Sprintf("Use the '%s' flag instead to provide one or more Ethereum RPC instances", flagEthRPCs))
diff --git a/cmd/peggo/grpcclient.go b/cmd/peggo/grpcclient.go
index 9be086da..ed9ad336 100644
--- a/cmd/peggo/grpcclient.go
+++ b/cmd/peggo/grpcclient.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"math/big"
+	"strings"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/ethclient"
@@ -44,8 +45,8 @@ func (em *EthRPCManager) DialNext() error {
 	if em.konfig == nil {
 		return errors.New("ethRPCManager konfig is nil")
 	}
-	//rpcs := em.konfig.Strings(flagEthRPCs)
-	rpcs := []string{em.konfig.String(flagEthRPC)}
+
+	rpcs := strings.Split(strings.ReplaceAll(em.konfig.String(flagEthRPCs), " ", ""), ",")
 
 	em.CloseClient()
 
diff --git a/test/e2e/e2e_setup_test.go b/test/e2e/e2e_setup_test.go
index e0c1ed1e..1be6031c 100644
--- a/test/e2e/e2e_setup_test.go
+++ b/test/e2e/e2e_setup_test.go
@@ -545,7 +545,7 @@ func (s *IntegrationTestSuite) runContractDeployment() {
 				"peggo",
 				"bridge",
 				"deploy-gravity",
-				"--eth-rpc",
+				"--eth-rpcs",
 				fmt.Sprintf("http://%s:8545", s.ethResource.Container.Name[1:]),
 				"--cosmos-grpc",
 				fmt.Sprintf("tcp://%s:9090", s.valResources[0].Container.Name[1:]),