Add batch limit option, use default region from config

README.MD

@@ -8,14 +8,14 @@
 
 ## Features
 
-* Reliable delivery. Messages are only deleted from the source queue if they were enqueued to the destination.
-* Messages are sent and received in batches for faster processing.
+* Reliable delivery. SQS Mover will only delete messages from the source queue after they were enqueued to the destination.
+* Receives and sends messages in batches for faster processing.
 * Progress indicator.
 * User friendly info and error messages.
 * Queue name resolution. For ease of use, you only need to provide a queue name and not the full `arn` address.
-* Message Attributes are copied over.
+* Message attributes copy.
 * Support for FIFO queues. MessageGroupId and MessageDeduplicationId are copied over to the destination messages.
-* Optional flag to limit the number of messages to move.
+* An optional flag to limit the number of messages to move.
 
 ## Getting Started
 
@@ -38,6 +38,12 @@ aws_secret_access_key = <YOUR_SECRET_ACCESS_KEY>
 
 The [default] heading defines credentials for the default profile, which the SQSMover will use unless you configure it to use another profile. 
 
+Optionally you can configure default region in `~/.aws/config`
+```
+[default]
+region=us-west-2
+```
+
 #### Environment variables
 
 As an alternative, you can setup AWS credentials in the environment variables.
@@ -117,11 +123,12 @@ usage: sqsmover --source=SOURCE --destination=DESTINATION [<flags>]
 Flags:
   -h, --help                     Show context-sensitive help (also try
                                  --help-long and --help-man).
-  -s, --source=SOURCE            Source queue name to move messages from.
-  -d, --destination=DESTINATION  Destination queue name to move messages to.
-  -r, --region="us-west-2"       AWS region for source and destination queues.
+  -s, --source=SOURCE            The source queue name to move messages from.
+  -d, --destination=DESTINATION  The destination queue name to move messages to.
+  -r, --region="us-west-2"       The AWS region for source and destination queues.
   -p, --profile=""               Use a specific profile from AWS credentials file.
-  -l, --limit=0                  Limits number of messages moved. No limit is set by default.
+  -l, --limit=0                  Limits total number of messages moved. No limit is set by default.
+  -b, --batch=10                 The maximum number of messages to move at a time.
   -v, --version                  Show application version.
 ```
 
@@ -148,3 +155,9 @@ Limit number of moved messages to 10
 sqsmover -s my_source_queue_name -d my_destination_queuename -l 10
 ```
 
+By default, `sqsmover` will try to move 10 messages at a time. However, if the total size of messages
+in a batch exceeds 256kb (262,144 bytes) you will receive an error: `Batch requests cannot be longer than 262144 bytes. You have sent x bytes.`
+To resolve, reduce the batch size by setting `-b` flag.
+```
+sqsmover -s my_source_queue_name -d my_destination_queuename -b 3
+```

go.mod

@@ -1,5 +1,7 @@
 module github.com/mercury2269/sqsmover
 
+go 1.14
+
 require (
 	github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc // indirect
 	github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf // indirect

main.go

@@ -25,11 +25,12 @@ var (
 )
 
 var (
-	sourceQueue      = kingpin.Flag("source", "Source queue name to move messages from.").Short('s').Required().String()
-	destinationQueue = kingpin.Flag("destination", "Destination queue name to move messages to.").Short('d').Required().String()
-	region           = kingpin.Flag("region", "AWS region for source and destination queues.").Short('r').Default("us-west-2").String()
-	profile          = kingpin.Flag("profile", "Use a specific profile from AWS credentials file.").Short('p').Default("").String()
-	limit            = kingpin.Flag("limit", "Limits number of messages moved. No limit is set by default.").Short('l').Default("0").Int()
+	sourceQueue      = kingpin.Flag("source", "The source queue name to move messages from.").Short('s').Required().String()
+	destinationQueue = kingpin.Flag("destination", "The destination queue name to move messages to.").Short('d').Required().String()
+	region           = kingpin.Flag("region", "The AWS region for source and destination queues.").Short('r').Default("").String()
+	profile          = kingpin.Flag("profile", "Use a specific profile from AWS credentials file.").Short('p').String()
+	limit            = kingpin.Flag("limit", "Limits total number of messages moved. No limit is set by default.").Short('l').Default("0").Int()
+	maxBatchSize     = kingpin.Flag("batch", "The maximum number of messages to move at a time").Short('b').Default("10").Int64()
 )
 
 func main() {
@@ -45,13 +46,16 @@ func main() {
 
 	kingpin.Parse()
 
-	sess, err := session.NewSessionWithOptions(
-		session.Options{
-			Config:            aws.Config{Region: aws.String(*region)},
-			Profile:           *profile,
-			SharedConfigState: session.SharedConfigEnable,
-		},
-	)
+	options := session.Options{
+		Profile:           *profile,
+		SharedConfigState: session.SharedConfigEnable,
+	}
+
+	if region != nil {
+		options.Config = aws.Config{Region: aws.String(*region)}
+	}
+
+	sess, err := session.NewSessionWithOptions(options)
 
 	if err != nil {
 		log.Error(color.New(color.FgRed).Sprintf("Unable to create AWS session for region \r\n", *region))
@@ -163,17 +167,16 @@ func convertSuccessfulMessageToBatchRequestEntry(messages []*sqs.Message) []*sqs
 }
 
 func moveMessages(sourceQueueUrl string, destinationQueueUrl string, svc *sqs.SQS, totalMessages int) {
-	params := &sqs.ReceiveMessageInput{
+	var params = &sqs.ReceiveMessageInput{
 		QueueUrl:              aws.String(sourceQueueUrl),
 		VisibilityTimeout:     aws.Int64(2),
 		WaitTimeSeconds:       aws.Int64(0),
-		MaxNumberOfMessages:   aws.Int64(10),
+		MaxNumberOfMessages:   aws.Int64(*maxBatchSize),
 		MessageAttributeNames: []*string{aws.String(sqs.QueueAttributeNameAll)},
 		AttributeNames: []*string{
 			aws.String(sqs.MessageSystemAttributeNameMessageGroupId),
 			aws.String(sqs.MessageSystemAttributeNameMessageDeduplicationId)},
 	}
-
 	log.Info(color.New(color.FgCyan).Sprintf("Starting to move messages..."))
 	fmt.Println()