[Filebeat] Add option for S3 input to work without SQS notification

CHANGELOG.next.asciidoc

@@ -80,6 +80,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix parsing of Elasticsearch node name by `elasticsearch/slowlog` fileset. {pull}14547[14547]
 - threatintel module: Changed the type of `threatintel.indicator.first_seen` from `keyword` to `date`. {pull}26765[26765]
 - Remove all alias fields pointing to ECS fields from modules. This affects the Suricata and Traefik modules. {issue}10535[10535] {pull}26627[26627]
+- Add option for S3 input to work without SQS notification {issue}18205[18205] {pull}27332[27332]
 
 *Heartbeat*
 - Remove long deprecated `watch_poll` functionality. {pull}27166[27166]

filebeat/docs/modules/aws.asciidoc

@@ -15,9 +15,14 @@ This file is generated! See scripts/docs_collector.py
 beta[]
 
 This is a module for aws logs. It uses filebeat s3 input to get log files from
-AWS S3 buckets with SQS notification. This module supports reading s3 server
-access logs with `s3access` fileset, ELB access logs with `elb` fileset, VPC
-flow logs with `vpcflow` fileset, and CloudTrail logs with `cloudtrail` fileset.
+AWS S3 buckets with SQS notification or directly polling list of S3 objects in an S3 bucket.
+The use of SQS notification is preferred: polling list of S3 objects is expensive
+in terms of performance and costs, and cannot scale horizontally without ingestion duplication,
+and should be preferably used only when no SQS notification can be attached to the S3 buckets.
+
+This module supports reading S3 server access logs with `s3access` fileset,
+ELB access logs with `elb` fileset, VPC flow logs with `vpcflow` fileset,
+and CloudTrail logs with `cloudtrail` fileset.
 
 Access logs contain detailed information about the requests made to these
 services. VPC flow logs captures information about the IP traffic going to and
@@ -44,6 +49,8 @@ Example config:
   cloudtrail:
     enabled: false
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
+    #var.s3_bucket: 'arn:aws:s3:::mybucket
+    #var.s3_bucket_poll_interval: 300s
     #var.shared_credential_file: /etc/filebeat/aws_credentials
     #var.credential_profile_name: fb-aws
     #var.access_key_id: access_key_id
@@ -58,6 +65,8 @@ Example config:
   cloudwatch:
     enabled: false
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
+    #var.s3_bucket: 'arn:aws:s3:::mybucket
+    #var.s3_bucket_poll_interval: 300s
     #var.shared_credential_file: /etc/filebeat/aws_credentials
     #var.credential_profile_name: fb-aws
     #var.access_key_id: access_key_id
@@ -72,6 +81,8 @@ Example config:
   ec2:
     enabled: false
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
+    #var.s3_bucket: 'arn:aws:s3:::mybucket
+    #var.s3_bucket_poll_interval: 300s
     #var.shared_credential_file: /etc/filebeat/aws_credentials
     #var.credential_profile_name: fb-aws
     #var.access_key_id: access_key_id
@@ -86,6 +97,8 @@ Example config:
   elb:
     enabled: false
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
+    #var.s3_bucket: 'arn:aws:s3:::mybucket
+    #var.s3_bucket_poll_interval: 300s
     #var.shared_credential_file: /etc/filebeat/aws_credentials
     #var.credential_profile_name: fb-aws
     #var.access_key_id: access_key_id
@@ -100,6 +113,8 @@ Example config:
   s3access:
     enabled: false
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
+    #var.s3_bucket: 'arn:aws:s3:::mybucket
+    #var.s3_bucket_poll_interval: 300s
     #var.shared_credential_file: /etc/filebeat/aws_credentials
     #var.credential_profile_name: fb-aws
     #var.access_key_id: access_key_id
@@ -114,6 +129,8 @@ Example config:
   vpcflow:
     enabled: false
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
+    #var.s3_bucket: 'arn:aws:s3:::mybucket
+    #var.s3_bucket_poll_interval: 300s
     #var.shared_credential_file: /etc/filebeat/aws_credentials
     #var.credential_profile_name: fb-aws
     #var.access_key_id: access_key_id
@@ -128,7 +145,7 @@ Example config:
 
 *`var.queue_url`*::
 
-(Required) AWS SQS queue url.
+AWS SQS queue url (Required when `var.s3_bucket` is not set).
 
 *`var.visibility_timeout`*::
 
@@ -139,6 +156,19 @@ Default to be 300 seconds.
 
 Maximum duration before AWS API request will be interrupted. Default to be 120 seconds.
 
+*`var.s3_bucket`*::
+
+AWS S3 bucket ARN (Required when `var.queue_url` is not set).
+
+*`var.s3_bucket_number_of_workers`*::
+
+Number of workers that will process the S3 objects listed (Required when `var.s3_bucket` is set).
+Use to vertically scale the input.
+
+*`var.s3_bucket_poll_interval`*::
+
+Interval between list requests to the S3 bucket. Default to be 120 seconds.
+
 *`var.endpoint`*::
 
 Custom endpoint used to access AWS APIs.

libbeat/publisher/testing/testing.go

@@ -28,8 +28,9 @@ type TestPublisher struct {
 
 // given channel only.
 type ChanClient struct {
-	done    chan struct{}
-	Channel chan beat.Event
+	done            chan struct{}
+	Channel         chan beat.Event
+	publishCallback func(event beat.Event)
 }
 
 func PublisherWithClient(client beat.Client) beat.Pipeline {
@@ -44,6 +45,13 @@ func (pub *TestPublisher) ConnectWith(_ beat.ClientConfig) (beat.Client, error)
 	return pub.client, nil
 }
 
+func NewChanClientWithCallback(bufSize int, callback func(event beat.Event)) *ChanClient {
+	chanClient := NewChanClientWith(make(chan beat.Event, bufSize))
+	chanClient.publishCallback = callback
+
+	return chanClient
+}
+
 func NewChanClient(bufSize int) *ChanClient {
 	return NewChanClientWith(make(chan beat.Event, bufSize))
 }
@@ -70,6 +78,10 @@ func (c *ChanClient) Publish(event beat.Event) {
 	select {
 	case <-c.done:
 	case c.Channel <- event:
+		if c.publishCallback != nil {
+			c.publishCallback(event)
+			<-c.Channel
+		}
 	}
 }
 

x-pack/filebeat/docs/inputs/input-aws-s3.asciidoc

@@ -12,12 +12,19 @@
 ++++
 
 Use the `aws-s3` input to retrieve logs from S3 objects that are pointed to by
-S3 notification events read from an SQS queue. This input can, for example, be
+S3 notification events read from an SQS queue or directly polling list of S3 objects in an S3 bucket.
+The use of SQS notification is preferred: polling list of S3 objects is expensive
+in terms of performance and costs and should be preferably used only when no SQS
+notification can be attached to the S3 buckets. This input can, for example, be
 used to receive S3 access logs to monitor detailed records for the requests that
 are made to a bucket.
 
-This input depends on S3 notifications delivered to an SQS queue for
-`s3:ObjectCreated:*` events. You must create an SQS queue and configure S3
+SQS notification method is enabled setting `queue_url` configuration value.
+S3 bucket list polling method is enabled setting `s3_bucket` configuration value.
+Both value cannot be set at the same time, at least one of the two value must be set.
+
+When using the SQS notification method this input depends on S3 notifications delivered
+to an SQS queue for `s3:ObjectCreated:*` events. You must create an SQS queue and configure S3
 to publish events to the queue.
 
 When processing a S3 object which pointed by a SQS message, if half of the set
@@ -36,6 +43,24 @@ be stopped and the SQS message will be returned back to the queue.
   expand_event_list_from_field: Records
 ----
 
+
+When using the direct polling list of S3 objects in an S3 buckets,
+a number of workers that will process the S3 objects listed must be set
+through the `s3_bucket_number_of_workers` config.
+Listing of the S3 bucket will be polled according the time interval defined by
+`s3_bucket_poll_interval` config. Default value is 120secs.
+
+["source","yaml",subs="attributes"]
+----
+{beatname_lc}.inputs:
+- type: aws-s3
+  s3_bucket: arn:aws:s3:::test-s3-bucket
+  s3_bucket_number_of_workers: 5
+  s3_bucket_poll_interval: 300s
+  credential_profile_name: elastic-beats
+  expand_event_list_from_field: Records
+----
+
 The `aws-s3` input supports the following configuration options plus the
 <<{beatname_lc}-input-{type}-common-options>> described later.
 
@@ -211,7 +236,7 @@ configuring multiline options.
 [float]
 ==== `queue_url`
 
-URL of the AWS SQS queue that messages will be received from. Required.
+URL of the AWS SQS queue that messages will be received from. (Required when `s3_bucket` is not set).
 
 [float]
 ==== `visibility_timeout`
@@ -242,6 +267,24 @@ The maximum duration that an SQS `ReceiveMessage` call should wait for a message
 to arrive in the queue before returning. The default value is `20s`. The maximum
 value is `20s`.
 
+[float]
+==== `s3_bucket`
+
+ARN of the AWS S3 bucket that will be polled for list operation. (Required when `queue_url` is not set).
+
+[float]
+==== `s3_bucket_poll_interval`
+
+Time interval for polling listing of the S3 bucket: default to `120s`.
+
+
+[float]
+==== `s3_bucket_number_of_workers`
+
+Number of workers that will process the S3 objects listed. (Required when `s3_bucket` is set).
+
+
+
 [float]
 ==== `aws credentials`
 
@@ -251,7 +294,8 @@ see <<aws-credentials-config,AWS credentials options>> for more details.
 [float]
 === AWS Permissions
 
-Specific AWS permissions are required for IAM user to access SQS and S3:
+Specific AWS permissions are required for IAM user to access SQS and S3
+when using the SQS notifications method:
 
 ----
 s3:GetObject
@@ -260,6 +304,14 @@ sqs:ChangeMessageVisibility
 sqs:DeleteMessage
 ----
 
+Reduced specific AWS permissions are required for IAM user to access S3
+when using the polling list of S3 bucket objects:
+
+----
+s3:GetObject
+s3:ListBucket
+----
+
 [float]
 === S3 and SQS setup
 
@@ -271,7 +323,7 @@ for more details.
 [float]
 === Parallel Processing
 
-Multiple Filebeat instances can read from the same SQS queues at the same time.
+When using the SQS notifications method, multiple {beatname_uc} instances can read from the same SQS queues at the same time.
 To horizontally scale processing when there are large amounts of log data
 flowing into an S3 bucket, you can run multiple {beatname_uc} instances that
 read from the same SQS queues at the same time. No additional configuration is
@@ -282,15 +334,25 @@ when multiple {beatname_uc} instances are running in parallel. To prevent
 {beatname_uc} from receiving and processing the message more than once, set the
 visibility timeout.
 
-The visibility timeout begins when SQS returns a message to Filebeat. During
-this time, Filebeat processes and deletes the message. However, if Filebeat
+The visibility timeout begins when SQS returns a message to {beatname_uc}. During
+this time, {beatname_uc} processes and deletes the message. However, if {beatname_uc}
 fails before deleting the message and your system doesn't call the DeleteMessage
 action for that message before the visibility timeout expires, the message
 becomes visible to other {beatname_uc} instances, and the message is received
 again. By default, the visibility timeout is set to 5 minutes for aws-s3 input
 in {beatname_uc}. 5 minutes is sufficient time for {beatname_uc} to read SQS
 messages and process related s3 log files.
 
+When using the polling list of S3 bucket objects method be aware that if running multiple {beatname_uc} instances,
+they can list the same S3 bucket at the same time. Since the state of the ingested S3 objects is persisted
+(upon processing every page of the listing operation) in the `path.data` configuration
+and multiple {beatname_uc} cannot share the same `path.data` this will produce repeated
+ingestion of the S3 object.
+Therefore, when using the polling list of S3 bucket objects method, scaling should be
+vertical, with a single bigger {beatname_uc} instance and higher `s3_bucket_number_of_workers`
+config value.
+
+
 [float]
 === Metrics
 

x-pack/filebeat/input/awss3/_meta/terraform/README.md

@@ -20,22 +20,24 @@ write the `outputs.yml`.
 
     `terraform apply`
 
-2. (Optional) View the output configuration.
+
+2. View the output configuration and assure the region match in the aws profile used to run
+the test or to set the environment variable `AWS_REGION` to the value in the output.
 
    ```yaml
    "aws_region": "us-east-1"
    "bucket_name": "filebeat-s3-integtest-8iok1h"
    "queue_url": "https://sqs.us-east-1.amazonaws.com/144492464627/filebeat-s3-integtest-8iok1h"
    ```
 
-2. Execute the integration test.
+4. Execute the integration test.
 
     ```
     cd x-pack/filebeat/inputs/awss3
-    go test -tags aws,integration -run TestInputRun -v .
+    go test -tags aws,integration -run TestInputRun.+ -v .
     ```
 
-3. Cleanup AWS resources. Execute terraform to remove the SQS queue and delete
+5. Cleanup AWS resources. Execute terraform to remove the SQS queue and delete
 the S3 bucket and its contents.
 
     `terraform destroy`

x-pack/filebeat/input/awss3/acker.go

@@ -28,8 +28,8 @@ func newEventACKTracker(ctx context.Context) *eventACKTracker {
 	return &eventACKTracker{ctx: ctx, cancel: cancel}
 }
 
-// Add increments the number of pending ACKs by the specified amount.
-func (a *eventACKTracker) Add(messageCount int64) {
+// Add increments the number of pending ACKs
+func (a *eventACKTracker) Add() {
 	a.Lock()
 	a.pendingACKs++
 	a.Unlock()

x-pack/filebeat/input/awss3/acker_test.go

@@ -18,7 +18,7 @@ func TestEventACKTracker(t *testing.T) {
 	t.Cleanup(cancel)
 
 	acker := newEventACKTracker(ctx)
-	acker.Add(1)
+	acker.Add()
 	acker.ACK()
 
 	assert.EqualValues(t, 0, acker.pendingACKs)
@@ -42,7 +42,7 @@ func TestEventACKHandler(t *testing.T) {
 
 	// Create acker. Add one pending ACK.
 	acker := newEventACKTracker(ctx)
-	acker.Add(1)
+	acker.Add()
 
 	// Create an ACK handler and simulate one ACKed event.
 	ackHandler := newEventACKHandler()