fix: error handling for invalid gRPC endpoints (#757)

cmd/connect/main.go

@@ -5,12 +5,13 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-
 	//nolint: gosec
 	_ "net/http/pprof"
 	"os"
 	"os/signal"
 	"path/filepath"
+	"regexp"
+	"strings"
 	"syscall"
 	"time"
 
@@ -322,6 +323,14 @@ func runOracle() error {
 		}
 	}
 
+	// check that the marketmap endpoint they provided is correct.
+	if marketMapProvider == marketmap.Name {
+		mmEndpoint := cfg.Providers[marketMapProvider].API.Endpoints[0].URL
+		if err := isValidGRPCEndpoint(mmEndpoint); err != nil {
+			return err
+		}
+	}
+
 	var marketCfg mmtypes.MarketMap
 	if marketCfgPath != "" {
 		marketCfg, err = mmtypes.ReadMarketMapFromFile(marketCfgPath)
@@ -467,3 +476,27 @@ func overwriteMarketMapEndpoint(cfg config.OracleConfig, overwrite string) (conf
 
 	return cfg, fmt.Errorf("no market-map provider found in config")
 }
+
+// isValidGRPCEndpoint checks that the string s is a valid gRPC endpoint. (doesn't start with http, ends with a port).
+func isValidGRPCEndpoint(s string) error {
+	if strings.HasPrefix(s, "http") {
+		return fmt.Errorf("expected gRPC endpoint but got HTTP endpoint %q. Please provide a gRPC endpoint (e.g. some.host:9090)", s)
+	}
+	if !hasPort(s) {
+		// they might do something like foo.bar:hello
+		// so lets just take the bit before foo.bar for the example in the error.
+		example := strings.Split(s, ":")[0]
+		return fmt.Errorf("invalid gRPC endpoint %q. Must specify port (e.g. %s:9090)", s, example)
+	}
+	return nil
+}
+
+// hasPort reports whether s contains `:` followed by numbers.
+func hasPort(s string) bool {
+	// matches anything that has `:` and some numbers after.
+	pattern := `:[0-9]+$`
+
+	regex := regexp.MustCompile(pattern)
+
+	return regex.MatchString(s)
+}

cmd/connect/main_test.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestCheckMarketMapEndpoint(t *testing.T) {
+	tests := []struct {
+		name     string
+		endpoint string
+		wantErr  bool
+		errMsg   string
+	}{
+		{
+			name:     "Valid gRPC endpoint",
+			endpoint: "example.com:8080",
+			wantErr:  false,
+		},
+		{
+			name:     "Valid IP address endpoint",
+			endpoint: "192.168.1.1:9090",
+			wantErr:  false,
+		},
+		{
+			name:     "HTTP endpoint",
+			endpoint: "http://example.com:8080",
+			wantErr:  true,
+			errMsg:   `expected gRPC endpoint but got HTTP endpoint "http://example.com:8080". Please provide a gRPC endpoint (e.g. some.host:9090)`,
+		},
+		{
+			name:     "HTTPS endpoint",
+			endpoint: "https://example.com:8080",
+			wantErr:  true,
+			errMsg:   `expected gRPC endpoint but got HTTP endpoint "https://example.com:8080". Please provide a gRPC endpoint (e.g. some.host:9090)`,
+		},
+		{
+			name:     "Missing port",
+			endpoint: "example.com",
+			wantErr:  true,
+			errMsg:   `invalid gRPC endpoint "example.com". Must specify port (e.g. example.com:9090)`,
+		},
+		{
+			name:     "Invalid port format",
+			endpoint: "example.com:port",
+			wantErr:  true,
+			errMsg:   `invalid gRPC endpoint "example.com:port". Must specify port (e.g. example.com:9090)`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := isValidGRPCEndpoint(tt.endpoint)
+			if tt.wantErr {
+				require.EqualError(t, err, tt.errMsg)
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}

providers/factories/oracle/marketmap.go

@@ -49,19 +49,19 @@ func MarketMapProviderFactory(
 		return nil, err
 	}
 
-	switch name := cfg.Name; {
-	case name == dydx.Name:
+	switch cfg.Name {
+	case dydx.Name:
 		apiDataHandler, err = dydx.NewAPIHandler(logger, cfg.API)
 		ids = []types.Chain{{ChainID: dydx.ChainID}}
-	case name == dydx.SwitchOverAPIHandlerName:
+	case dydx.SwitchOverAPIHandlerName:
 		marketMapFetcher, err = dydx.NewDefaultSwitchOverMarketMapFetcher(
 			logger,
 			cfg.API,
 			requestHandler,
 			apiMetrics,
 		)
 		ids = []types.Chain{{ChainID: dydx.ChainID}}
-	case name == dydx.ResearchAPIHandlerName || name == dydx.ResearchCMCAPIHandlerName:
+	case dydx.ResearchAPIHandlerName, dydx.ResearchCMCAPIHandlerName:
 		marketMapFetcher, err = dydx.DefaultDYDXResearchMarketMapFetcher(
 			requestHandler,
 			apiMetrics,