Add an health endpoint to OG (#1427)

* Add an health endpoint to OG

* lint

* Update integration/obscurogateway/obscurogateway_test.go

integration/obscurogateway/obscurogateway_test.go

@@ -4,9 +4,14 @@ import (
 	"context"
 	"fmt"
 	"math/big"
+	"net/http"
+	"strings"
 	"testing"
 	"time"
 
+	"github.com/stretchr/testify/require"
+	"github.com/valyala/fasthttp"
+
 	gethcommon "github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/log"
@@ -66,8 +71,11 @@ func TestObscuroGateway(t *testing.T) {
 	time.Sleep(5 * time.Second)
 
 	// make sure the server is ready to receive requests
-	// TODO Implement health endpoint
-	// serverAddress := fmt.Sprintf("http://%s:%d", obscuroGatewayConf.WalletExtensionHost, obscuroGatewayConf.WalletExtensionPortHTTP)
+	serverAddress := fmt.Sprintf("http://%s:%d", obscuroGatewayConf.WalletExtensionHost, obscuroGatewayConf.WalletExtensionPortHTTP)
+
+	// make sure the server is ready to receive requests
+	err := waitServerIsReady(serverAddress)
+	require.NoError(t, err)
 
 	w := wallets.L2FaucetWallet
 
@@ -171,3 +179,21 @@ func createObscuroNetwork(t *testing.T, startPort int) *params.SimWallets {
 	}
 	return wallets
 }
+
+func waitServerIsReady(serverAddr string) error {
+	for now := time.Now(); time.Since(now) < 30*time.Second; time.Sleep(500 * time.Millisecond) {
+		statusCode, _, err := fasthttp.Get(nil, fmt.Sprintf("%s/health/", serverAddr))
+		if err != nil {
+			// give it time to boot up
+			if strings.Contains(err.Error(), "connection") {
+				continue
+			}
+			return err
+		}
+
+		if statusCode == http.StatusOK {
+			return nil
+		}
+	}
+	return fmt.Errorf("timed out before server was ready")
+}

tools/walletextension/api/routes.go

@@ -58,6 +58,10 @@ func NewHTTPRoutes(walletExt *walletextension.WalletExtension) []Route {
 			Name: common.PathRevoke,
 			Func: httpHandler(walletExt, revokeRequestHandler),
 		},
+		{
+			Name: common.PathHealth,
+			Func: httpHandler(walletExt, healthRequestHandler),
+		},
 	}
 }
 
@@ -415,3 +419,18 @@ func revokeRequestHandler(walletExt *walletextension.WalletExtension, userConn u
 		walletExt.Logger().Error(fmt.Errorf("error writing success response, %w", err).Error())
 	}
 }
+
+// Handles request to /health endpoint.
+func healthRequestHandler(walletExt *walletextension.WalletExtension, userConn userconn.UserConn) {
+	// read the request
+	_, err := userConn.ReadRequest()
+	if err != nil {
+		walletExt.Logger().Error(fmt.Errorf("error reading request: %w", err).Error())
+		return
+	}
+
+	err = userConn.WriteResponse([]byte(common.SuccessMsg))
+	if err != nil {
+		walletExt.Logger().Error(fmt.Errorf("error writing success response, %w", err).Error())
+	}
+}

tools/walletextension/common/constants.go

@@ -36,6 +36,7 @@ const (
 	PathAuthenticate          = "/authenticate/"
 	PathQuery                 = "/query/"
 	PathRevoke                = "/revoke/"
+	PathHealth                = "/health/"
 	WSProtocol                = "ws://"
 	DefaultUser               = "defaultUser"
 	UserQueryParameter        = "u"