Prevent remoteReadClusters from being []string{""} when no remote clu…

…sters are provided

plugin/storage/es/options.go

@@ -286,7 +286,6 @@ func initFromViper(cfg *namespaceConfig, v *viper.Viper) {
 	cfg.Sniffer = v.GetBool(cfg.namespace + suffixSniffer)
 	cfg.SnifferTLSEnabled = v.GetBool(cfg.namespace + suffixSnifferTLSEnabled)
 	cfg.Servers = strings.Split(stripWhiteSpace(v.GetString(cfg.namespace+suffixServerURLs)), ",")
-	cfg.RemoteReadClusters = strings.Split(stripWhiteSpace(v.GetString(cfg.namespace+suffixRemoteReadClusters)), ",")
 	cfg.MaxSpanAge = v.GetDuration(cfg.namespace + suffixMaxSpanAge)
 	cfg.NumShards = v.GetInt64(cfg.namespace + suffixNumShards)
 	cfg.NumReplicas = v.GetInt64(cfg.namespace + suffixNumReplicas)
@@ -313,6 +312,11 @@ func initFromViper(cfg *namespaceConfig, v *viper.Viper) {
 	// TODO: Need to figure out a better way for do this.
 	cfg.AllowTokenFromContext = v.GetBool(spanstore.StoragePropagationKey)
 	cfg.TLS = cfg.getTLSFlagsConfig().InitFromViper(v)
+
+	remoteReadClusters := stripWhiteSpace(v.GetString(cfg.namespace + suffixRemoteReadClusters))
+	if len(remoteReadClusters) > 0 {
+		cfg.RemoteReadClusters = strings.Split(remoteReadClusters, ",")
+	}
 }
 
 // GetPrimary returns primary configuration.

plugin/storage/es/options_test.go

@@ -31,6 +31,7 @@ func TestOptions(t *testing.T) {
 	assert.Empty(t, primary.Username)
 	assert.Empty(t, primary.Password)
 	assert.NotEmpty(t, primary.Servers)
+	assert.Empty(t, primary.RemoteReadClusters)
 	assert.Equal(t, int64(5), primary.NumShards)
 	assert.Equal(t, int64(1), primary.NumReplicas)
 	assert.Equal(t, 72*time.Hour, primary.MaxSpanAge)
@@ -58,6 +59,7 @@ func TestOptionsWithFlags(t *testing.T) {
 		"--es.num-replicas=10",
 		"--es.index-date-separator=",
 		// a couple overrides
+		"--es.remote-read-clusters=cluster_one,cluster_two",
 		"--es.aux.server-urls=3.3.3.3, 4.4.4.4",
 		"--es.aux.max-span-age=24h",
 		"--es.aux.num-replicas=10",
@@ -77,6 +79,7 @@ func TestOptionsWithFlags(t *testing.T) {
 	assert.Equal(t, "hello", primary.Username)
 	assert.Equal(t, "/foo/bar", primary.TokenFilePath)
 	assert.Equal(t, []string{"1.1.1.1", "2.2.2.2"}, primary.Servers)
+	assert.Equal(t, []string{"cluster_one", "cluster_two"}, primary.RemoteReadClusters)
 	assert.Equal(t, 48*time.Hour, primary.MaxSpanAge)
 	assert.True(t, primary.Sniffer)
 	assert.True(t, primary.SnifferTLSEnabled)
@@ -103,6 +106,19 @@ func TestOptionsWithFlags(t *testing.T) {
 	assert.True(t, primary.UseILM)
 }
 
+func TestEmptyRemoteReadClusters(t *testing.T) {
+	opts := NewOptions("es", "es.aux")
+	v, command := config.Viperize(opts.AddFlags)
+	err := command.ParseFlags([]string{
+		"--es.remote-read-clusters=",
+	})
+	require.NoError(t, err)
+	opts.InitFromViper(v)
+
+	primary := opts.GetPrimary()
+	assert.Equal(t, []string{}, primary.RemoteReadClusters)
+}
+
 func TestMaxSpanAgeSetErrorInArchiveMode(t *testing.T) {
 	opts := NewOptions("es", archiveNamespace)
 	_, command := config.Viperize(opts.AddFlags)