Allow remote reindex from a remote cluster

VERSION

@@ -1 +1 @@
-0.2.0
+0.3.0

cli/app.go

@@ -143,6 +143,7 @@ func Reindex() cli.Command {
 			cli.StringFlag{Name: "reindex-host-allocation", Usage: "Optional target host for the reindex to happen on. eg. 'es-reindex-*'"},
 			cli.StringFlag{Name: "dest-host-allocation", Usage: "Optional target host once the reindex is complete. eg. 'es-data-*'"},
 			cli.StringFlag{Name: "extra-suffix", Usage: "Optional extra suffix name to add to index name (after date). Ignored if dest-index is set"},
+			cli.StringFlag{Name: "remote-src", Usage: "Remote ElasticSearch cluster to reindex from. eg. 'http://es-client:9200'"},
 		},
 		Action: func(c *cli.Context) error {
 			if c.NArg() == 0 || c.NArg() > 1 {
@@ -174,7 +175,7 @@ func Reindex() cli.Command {
 
 				_, fileName := filepath.Split(filePath)
 				alias := strings.TrimSuffix(fileName, ".json")
-				if err = elasticsearch.ReindexOne(client, alias, newIndex, c.Bool("version-external"), c.Bool("no-update-alias"), c.Bool("bulk-indexing")); err != nil {
+				if err = elasticsearch.ReindexOne(client, alias, newIndex, c.String("remote-src"), c.Bool("version-external"), c.Bool("no-update-alias"), c.Bool("bulk-indexing")); err != nil {
 					return err
 				}
 
@@ -200,7 +201,7 @@ func Reindex() cli.Command {
 				return err
 			}
 
-			if err = elasticsearch.ReindexAll(client, aliasToNewIndex); err != nil {
+			if err = elasticsearch.ReindexAll(client, aliasToNewIndex, c.String("remote-src")); err != nil {
 				return err
 			}
 

elasticsearch/elasdx.go

@@ -125,7 +125,7 @@ func UpdateTemplatesAndCreateNewIndices(client *elastic.Client, templatesDir str
 	return aliasToNewIndex, err
 }
 
-func ReindexOne(client *elastic.Client, alias, newIndex string, versionExternal, noUpdateAlias, bulkIndexing bool) error {
+func ReindexOne(client *elastic.Client, alias, newIndex, remoteSrc string, versionExternal, noUpdateAlias, bulkIndexing bool) error {
 	// We assume that we are reindexing from an existing index on the alias
 	reindexingRequired := true
 
@@ -142,16 +142,26 @@ func ReindexOne(client *elastic.Client, alias, newIndex string, versionExternal,
 	}
 
 	// If we have data in an existing index that needs to be reindex with the new template to the new index
-	if reindexingRequired {
-		// We should only ever get one result if our naming is sensible
-		indicesFromAlias := aliasResult.IndicesByAlias(alias)
+	// Also assume the remote index exists if specificed a remote source cluster
+	if reindexingRequired || remoteSrc != "" {
+		// Default to alias name (used for remote clusters only)
+		indicesFromAlias := []string{alias}
+		if remoteSrc == "" {
+			// Search for indexname based off alias. We should only ever get one result if our naming is sensible
+			indicesFromAlias = aliasResult.IndicesByAlias(alias)
+		}
 		for _, index := range indicesFromAlias {
 			// Reindex from the existing index as the source to the new index as the destination
 			targetVersionType := "internal"
 			if versionExternal {
 				targetVersionType = "external"
 			}
 			src := elastic.NewReindexSource().Index(index)
+			if remoteSrc != "" {
+				// A remote cluster
+				remoteReindexSrc := elastic.NewReindexRemoteInfo().Host(remoteSrc)
+				src = elastic.NewReindexSource().Index(index).RemoteInfo(remoteReindexSrc)
+			}
 			dst := elastic.NewReindexDestination().Index(newIndex).VersionType(targetVersionType)
 			refresh, err := client.Reindex().Source(src).Destination(dst).Refresh("true").Conflicts("proceed").Do(context.Background())
 			if err != nil {
@@ -267,9 +277,9 @@ func UpdateHostAllocation(client *elastic.Client, newIndex, allocation string) e
 	return nil
 }
 
-func ReindexAll(client *elastic.Client, aliasToNewIndex map[string]string) error {
+func ReindexAll(client *elastic.Client, aliasToNewIndex map[string]string, remoteSrc string) error {
 	for alias, newIndex := range aliasToNewIndex {
-		if err := ReindexOne(client, alias, newIndex, false, false, false); err != nil {
+		if err := ReindexOne(client, alias, newIndex, remoteSrc, false, false, false); err != nil {
 			return errors.Wrapf(err, "failed reindexing to %s and adding to alias %s", newIndex, alias)
 		}
 	}