Do not throw error on empty indices in Elasticsach rollover lookback

cmd/es-rollover/app/lookback/action.go

@@ -15,9 +15,10 @@
 package lookback
 
 import (
-	"fmt"
 	"time"
 
+	"go.uber.org/zap"
+
 	"github.com/jaegertracing/jaeger/cmd/es-rollover/app"
 	"github.com/jaegertracing/jaeger/pkg/es/client"
 	"github.com/jaegertracing/jaeger/pkg/es/filter"
@@ -29,6 +30,7 @@ var timeNow func() time.Time = time.Now
 type Action struct {
 	Config
 	IndicesClient client.IndexAPI
+	Logger        *zap.Logger
 }
 
 // Do the lookback action
@@ -54,16 +56,19 @@ func (a *Action) lookback(indexSet app.IndexOption) error {
 	finalIndices := filter.ByDate(excludedWriteIndex, getTimeReference(timeNow(), a.Unit, a.UnitCount))
 
 	if len(finalIndices) == 0 {
-		return fmt.Errorf("no indices to remove from alias %s", readAliasName)
+		a.Logger.Info("No indices to remove from alias", zap.String("readAliasName", readAliasName))
+		return nil
 	}
 
 	aliases := make([]client.Alias, 0, len(finalIndices))
+	a.Logger.Info("About to remove indices", zap.String("readAliasName", readAliasName), zap.Int("indicesCount", len(finalIndices)))
 
 	for _, index := range finalIndices {
 		aliases = append(aliases, client.Alias{
 			Index: index.Index,
 			Name:  readAliasName,
 		})
+		a.Logger.Info("To be removed", zap.String("index", index.Index), zap.String("creationTime", index.CreationTime.String()))
 	}
 
 	return a.IndicesClient.DeleteAlias(aliases)

cmd/es-rollover/app/lookback/action_test.go

@@ -20,6 +20,7 @@ import (
 	"time"
 
 	"github.com/stretchr/testify/assert"
+	"go.uber.org/zap"
 
 	"github.com/jaegertracing/jaeger/cmd/es-rollover/app"
 	"github.com/jaegertracing/jaeger/pkg/es/client"
@@ -116,7 +117,7 @@ func TestLookBackAction(t *testing.T) {
 			expectedErr: errors.New("get indices error"),
 		},
 		{
-			name: "empty indices error",
+			name: "empty indices",
 			setupCallExpectations: func(indexClient *mocks.MockIndexAPI) {
 				indexClient.On("GetJaegerIndices", "").Return([]client.Index{}, nil)
 			},
@@ -128,16 +129,19 @@ func TestLookBackAction(t *testing.T) {
 					UseILM:  true,
 				},
 			},
-			expectedErr: errors.New("no indices to remove from alias jaeger-span-archive-read"),
+			expectedErr: nil,
 		},
 	}
 
+	logger, _ := zap.NewProduction()
+
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			indexClient := &mocks.MockIndexAPI{}
 			lookbackAction := Action{
 				Config:        test.config,
 				IndicesClient: indexClient,
+				Logger:        logger,
 			}
 
 			test.setupCallExpectations(indexClient)

cmd/es-rollover/main.go

@@ -134,6 +134,7 @@ func main() {
 				return &lookback.Action{
 					IndicesClient: indicesClient,
 					Config:        lookbackCfg,
+					Logger:        logger,
 				}
 			})
 		},