go/config: Allow only clients and observers to use remote storage

Author: martintomazic

go/config/config.go

@@ -87,6 +87,17 @@ func (c *Config) Validate() error {
 		return fmt.Errorf("unknown node mode: %s", c.Mode)
 	}
 
+	if !c.Consensus.LocalStorage {
+		if c.Consensus.Validator {
+			return fmt.Errorf("local storage not available in specified mode")
+		}
+		switch c.Mode {
+		case ModeClient, ModeObserver:
+		default:
+			return fmt.Errorf("local storage not available in specified mode")
+		}
+	}
+
 	if err = c.Common.Validate(); err != nil {
 		return fmt.Errorf("common: %w", err)
 	}

go/config/config_test.go

@@ -0,0 +1,39 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestRemoteStorageValidation(t *testing.T) {
+	for _, tc := range []struct {
+		name      string
+		mode      NodeMode
+		validator bool
+		mustErr   bool
+	}{
+		{name: "client", mode: ModeClient},
+		{name: "observer", mode: ModeObserver},
+		{name: "validator", mode: ModeValidator, mustErr: true},
+		{name: "compute", mode: ModeCompute, mustErr: true},
+		{name: "keymanager", mode: ModeKeyManager, mustErr: true},
+		{name: "seed", mode: ModeSeed, mustErr: true},
+		{name: "archive", mode: ModeArchive, mustErr: true},
+		{name: "consensus validator and observer", mode: ModeObserver, validator: true, mustErr: true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			cfg := DefaultConfig()
+			cfg.Mode = tc.mode
+			cfg.Consensus.LocalStorage = false
+			cfg.Consensus.Validator = tc.validator
+
+			err := cfg.Validate()
+			if tc.mustErr {
+				require.ErrorContains(t, err, "local storage not available in specified mode")
+			} else {
+				require.NoError(t, err)
+			}
+		})
+	}
+}