soroban-rpc: improve missing command line arguments message

cmd/soroban-rpc/internal/config/config_option.go

@@ -17,13 +17,28 @@ type ConfigOptions []*ConfigOption
 
 // Validate all the config options.
 func (options ConfigOptions) Validate() error {
+	var missingOptions []errMissingRequiredOption
 	for _, option := range options {
 		if option.Validate != nil {
 			err := option.Validate(option)
-			if err != nil {
-				return errors.Wrap(err, fmt.Sprintf("Invalid config value for %s", option.Name))
+			if err == nil {
+				continue
 			}
+			if missingOption, ok := err.(errMissingRequiredOption); ok {
+				missingOptions = append(missingOptions, missingOption)
+				continue
+			}
+			return errors.Wrap(err, fmt.Sprintf("Invalid config value for %s", option.Name))
+		}
+	}
+	if len(missingOptions) > 0 {
+		// we had one or more missing options, combine these all into a single error.
+		errString := "The following required configuration parameters are missing:"
+		for _, missingOpt := range missingOptions {
+			errString += "\n*\t" + missingOpt.strErr
+			errString += "\n \t" + missingOpt.usage
 		}
+		return &errMissingRequiredOption{strErr: errString}
 	}
 	return nil
 }

cmd/soroban-rpc/internal/config/config_test.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
-	"github.com/stellar/go/network"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -48,7 +47,7 @@ func TestConfigLoadDefaults(t *testing.T) {
 	require.NoError(t, cfg.loadDefaults())
 
 	// Check that the defaults are set
-	assert.Equal(t, network.FutureNetworkPassphrase, cfg.NetworkPassphrase)
+	assert.Equal(t, defaultHTTPEndpoint, cfg.Endpoint)
 	assert.Equal(t, uint(runtime.NumCPU()), cfg.PreflightWorkerCount)
 }
 

cmd/soroban-rpc/internal/config/options.go

@@ -16,6 +16,8 @@ import (
 	"github.com/stellar/soroban-tools/cmd/soroban-rpc/internal/ledgerbucketwindow"
 )
 
+const defaultHTTPEndpoint = "localhost:8000"
+
 func (cfg *Config) options() ConfigOptions {
 	if cfg.optionsCache != nil {
 		return *cfg.optionsCache
@@ -41,7 +43,7 @@ func (cfg *Config) options() ConfigOptions {
 			Name:         "endpoint",
 			Usage:        "Endpoint to listen and serve on",
 			ConfigKey:    &cfg.Endpoint,
-			DefaultValue: "localhost:8000",
+			DefaultValue: defaultHTTPEndpoint,
 		},
 		{
 			Name:      "admin-endpoint",
@@ -189,11 +191,10 @@ func (cfg *Config) options() ConfigOptions {
 			ConfigKey: &cfg.FriendbotURL,
 		},
 		{
-			Name:         "network-passphrase",
-			Usage:        "Network passphrase of the Stellar network transactions should be signed for",
-			ConfigKey:    &cfg.NetworkPassphrase,
-			DefaultValue: network.FutureNetworkPassphrase,
-			Validate:     required,
+			Name:      "network-passphrase",
+			Usage:     "Network passphrase of the Stellar network transactions should be signed for. Commonly used values are \"" + network.FutureNetworkPassphrase + "\", \"" + network.TestNetworkPassphrase + "\" and \"" + network.PublicNetworkPassphrase + "\"",
+			ConfigKey: &cfg.NetworkPassphrase,
+			Validate:  required,
 		},
 		{
 			Name:         "db-path",
@@ -399,9 +400,25 @@ func (cfg *Config) options() ConfigOptions {
 	return *cfg.optionsCache
 }
 
+type errMissingRequiredOption struct {
+	strErr string
+	usage  string
+}
+
+func (e errMissingRequiredOption) Error() string {
+	return e.strErr
+}
+
 func required(option *ConfigOption) error {
-	if !reflect.ValueOf(option.ConfigKey).Elem().IsZero() {
-		return nil
+	switch reflect.ValueOf(option.ConfigKey).Elem().Kind() {
+	case reflect.Slice:
+		if reflect.ValueOf(option.ConfigKey).Elem().Len() > 0 {
+			return nil
+		}
+	default:
+		if !reflect.ValueOf(option.ConfigKey).Elem().IsZero() {
+			return nil
+		}
 	}
 
 	waysToSet := []string{}
@@ -426,7 +443,7 @@ func required(option *ConfigOption) error {
 		advice = fmt.Sprintf(" Please %s, %s, or %s.", waysToSet[0], waysToSet[1], waysToSet[2])
 	}
 
-	return fmt.Errorf("%s is required.%s", option.Name, advice)
+	return errMissingRequiredOption{strErr: fmt.Sprintf("%s is required.%s", option.Name, advice), usage: option.Usage}
 }
 
 func positive(option *ConfigOption) error {

cmd/soroban-rpc/internal/config/toml_test.go

@@ -80,7 +80,7 @@ func TestBasicTomlWriting(t *testing.T) {
 
 	// Spot-check that the output looks right. Try to check one value for each
 	// type of option. (string, duration, uint, etc...)
-	assert.Contains(t, out, "NETWORK_PASSPHRASE = \"Test SDF Future Network ; October 2022\"")
+	assert.Contains(t, out, "ENDPOINT = \"localhost:8000\"")
 	assert.Contains(t, out, "STELLAR_CORE_TIMEOUT = \"2s\"")
 	assert.Contains(t, out, "STELLAR_CAPTIVE_CORE_HTTP_PORT = 11626")
 	assert.Contains(t, out, "LOG_LEVEL = \"info\"")