[Filebeat] Add support for Cloudtrail digest files (elastic#21086)

* Add support for Cloudtrail digest files

- allow file matching with file_selectors in s3 input
- update cloudtrail pipeline
- update cloudtrail config to use file_selectors
- add cloudtrail digest fields
- add cloudtrail insight fields

Closes elastic#20943

CHANGELOG.next.asciidoc

@@ -263,6 +263,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Provide backwards compatibility for the `set` processor when Elasticsearch is less than 7.9.0. {pull}20908[20908]
 - Remove wrongly mapped `tls.client.server_name` from `fortinet/firewall` fileset. {pull}20983[20983]
 - Fix an error updating file size being logged when EOF is reached. {pull}21048[21048]
+- Fix error when processing AWS Cloudtrail Digest logs. {pull}21086[21086] {issue}20943[20943]
 
 *Heartbeat*
 

filebeat/docs/fields.asciidoc

@@ -1488,6 +1488,120 @@ type: flattened
 
 --
 
+[float]
+=== digest
+
+Fields from Cloudtrail Digest Logs
+
+
+*`aws.cloudtrail.digest.log_files`*::
++
+--
+A list of Logfiles contained in the digest.
+
+type: nested
+
+--
+
+*`aws.cloudtrail.digest.start_time`*::
++
+--
+The starting UTC time range that the digest file covers, taking as a reference the time in which log files have been delivered by CloudTrail.
+
+type: date
+
+--
+
+*`aws.cloudtrail.digest.end_time`*::
++
+--
+The ending UTC time range that the digest file covers, taking as a reference the time in which log files have been delivered by CloudTrail.
+
+type: date
+
+--
+
+*`aws.cloudtrail.digest.s3_bucket`*::
++
+--
+The name of the Amazon S3 bucket to which the current digest file has been delivered.
+
+type: keyword
+
+--
+
+*`aws.cloudtrail.digest.s3_object`*::
++
+--
+The Amazon S3 object key (that is, the Amazon S3 bucket location) of the current digest file.
+
+type: keyword
+
+--
+
+*`aws.cloudtrail.digest.newest_event_time`*::
++
+--
+The UTC time of the most recent event among all of the events in the log files in the digest.
+
+type: date
+
+--
+
+*`aws.cloudtrail.digest.oldest_event_time`*::
++
+--
+The UTC time of the oldest event among all of the events in the log files in the digest.
+
+type: date
+
+--
+
+*`aws.cloudtrail.digest.previous_s3_bucket`*::
++
+--
+The Amazon S3 bucket to which the previous digest file was delivered.
+
+type: keyword
+
+--
+
+*`aws.cloudtrail.digest.previous_hash_algorithm`*::
++
+--
+The name of the hash algorithm that was used to hash the previous digest file.
+
+type: keyword
+
+--
+
+*`aws.cloudtrail.digest.public_key_fingerprint`*::
++
+--
+The hexadecimal encoded fingerprint of the public key that matches the private key used to sign this digest file.
+
+type: keyword
+
+--
+
+*`aws.cloudtrail.digest.signature_algorithm`*::
++
+--
+The algorithm used to sign the digest file.
+
+type: keyword
+
+--
+
+*`aws.cloudtrail.insight_details`*::
++
+--
+Shows information about the underlying triggers of an Insights event, such as event source, user agent, statistics, API name, and whether the event is the start or end of the Insights event.
+
+type: flattened
+
+--
+
 [float]
 === cloudwatch
 

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

@@ -67,6 +67,31 @@ type will not be checked.
 If a file has "application/json" content-type, `expand_event_list_from_field`
 becomes required to read the json file.
 
+[float]
+==== `file_selectors`
+
+If the SQS queue will have events that correspond to files that
+{beatname_uc} shouldn't process `file_selectors` can be used to limit
+the files that are downloaded.  This is a list of selectors which are
+made up of `regex` and `expand_event_list_from_field` options.  The
+`regex` should match the S3 object key in the SQS message, and the
+optional `expand_event_list_from_field` is the same as the global
+setting.  If `file_selectors` is given, then any global
+`expand_event_list_from_field` value is ignored in favor of the ones
+specified in the `file_selectors`.  Regex syntax is the same as the Go
+language.  Files that don't match one of the regexes won't be
+processed.
+
+["source", "yml"]
+----
+file_selectors:
+  - regex: '^AWSLogs/\d+/CloudTrail/'
+    expand_event_list_from_field: 'Records'
+  - regex: '^AWSLogs/\d+/CloudTrail-Digest'
+```
+----
+
+
 [float]
 ==== `api_timeout`
 

x-pack/filebeat/filebeat.reference.yml

@@ -102,6 +102,18 @@ filebeat.modules:
     # AWS SQS queue url
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
 
+    # Process CloudTrail logs
+    # default is true, set to false to skip Cloudtrail logs
+    # var.process_cloudtrail_logs: false
+
+    # Process CloudTrail Digest logs
+    # default true, set to false to skip CloudTrail Digest logs
+    # var.process_digest_logs: false
+
+    # Process CloudTrail Insight logs
+    # default true, set to false to skip CloudTrail Insight logs
+    # var.process_insight_logs: false
+
     # Filename of AWS credential file
     # If not set "$HOME/.aws/credentials" is used on Linux/Mac
     # "%UserProfile%\.aws\credentials" is used on Windows

x-pack/filebeat/input/s3/config.go

@@ -6,6 +6,7 @@ package s3
 
 import (
 	"fmt"
+	"regexp"
 	"time"
 
 	"github.com/elastic/beats/v7/filebeat/harvester"
@@ -19,6 +20,14 @@ type config struct {
 	AwsConfig                 awscommon.ConfigAWS `config:",inline"`
 	ExpandEventListFromField  string              `config:"expand_event_list_from_field"`
 	APITimeout                time.Duration       `config:"api_timeout"`
+	FileSelectors             []FileSelectorCfg   `config:"file_selectors"`
+}
+
+// FileSelectorCfg defines type and configuration of FileSelectors
+type FileSelectorCfg struct {
+	RegexString              string         `config:"regex"`
+	Regex                    *regexp.Regexp `config:",ignore"`
+	ExpandEventListFromField string         `config:"expand_event_list_from_field"`
 }
 
 func defaultConfig() config {
@@ -40,5 +49,12 @@ func (c *config) Validate() error {
 		return fmt.Errorf("api timeout %v needs to be larger than"+
 			" 0s and smaller than half of the visibility timeout", c.APITimeout)
 	}
+	for i := range c.FileSelectors {
+		r, err := regexp.Compile(c.FileSelectors[i].RegexString)
+		if err != nil {
+			return err
+		}
+		c.FileSelectors[i].Regex = r
+	}
 	return nil
 }

x-pack/filebeat/input/s3/input.go

@@ -74,10 +74,11 @@ type s3Input struct {
 }
 
 type s3Info struct {
-	name   string
-	key    string
-	region string
-	arn    string
+	name                     string
+	key                      string
+	region                   string
+	arn                      string
+	expandEventListFromField string
 }
 
 type bucket struct {
@@ -252,7 +253,7 @@ func (p *s3Input) processor(queueURL string, messages []sqs.Message, visibilityT
 func (p *s3Input) processMessage(svcS3 s3iface.ClientAPI, message sqs.Message, wg *sync.WaitGroup, errC chan error) {
 	defer wg.Done()
 
-	s3Infos, err := handleSQSMessage(message)
+	s3Infos, err := p.handleSQSMessage(message)
 	if err != nil {
 		p.logger.Error(errors.Wrap(err, "handleSQSMessage failed"))
 		return
@@ -352,7 +353,7 @@ func getRegionFromQueueURL(queueURL string) (string, error) {
 }
 
 // handle message
-func handleSQSMessage(m sqs.Message) ([]s3Info, error) {
+func (p *s3Input) handleSQSMessage(m sqs.Message) ([]s3Info, error) {
 	msg := sqsMessage{}
 	err := json.Unmarshal([]byte(*m.Body), &msg)
 	if err != nil {
@@ -361,21 +362,40 @@ func handleSQSMessage(m sqs.Message) ([]s3Info, error) {
 
 	var s3Infos []s3Info
 	for _, record := range msg.Records {
-		if record.EventSource == "aws:s3" && strings.HasPrefix(record.EventName, "ObjectCreated:") {
-			// Unescape substrings from s3 log name. For example, convert "%3D" back to "="
-			filename, err := url.QueryUnescape(record.S3.object.Key)
-			if err != nil {
-				return nil, errors.Wrapf(err, "url.QueryUnescape failed for '%s'", record.S3.object.Key)
-			}
+		if record.EventSource != "aws:s3" || !strings.HasPrefix(record.EventName, "ObjectCreated:") {
+			return nil, errors.New("this SQS queue should be dedicated to s3 ObjectCreated event notifications")
+		}
+		// Unescape substrings from s3 log name. For example, convert "%3D" back to "="
+		filename, err := url.QueryUnescape(record.S3.object.Key)
+		if err != nil {
+			return nil, errors.Wrapf(err, "url.QueryUnescape failed for '%s'", record.S3.object.Key)
+		}
 
+		if len(p.config.FileSelectors) == 0 {
 			s3Infos = append(s3Infos, s3Info{
-				region: record.AwsRegion,
-				name:   record.S3.bucket.Name,
-				key:    filename,
-				arn:    record.S3.bucket.Arn,
+				region:                   record.AwsRegion,
+				name:                     record.S3.bucket.Name,
+				key:                      filename,
+				arn:                      record.S3.bucket.Arn,
+				expandEventListFromField: p.config.ExpandEventListFromField,
 			})
-		} else {
-			return nil, errors.New("this SQS queue should be dedicated to s3 ObjectCreated event notifications")
+			continue
+		}
+
+		for _, fs := range p.config.FileSelectors {
+			if fs.Regex == nil {
+				continue
+			}
+			if fs.Regex.MatchString(filename) {
+				s3Infos = append(s3Infos, s3Info{
+					region:                   record.AwsRegion,
+					name:                     record.S3.bucket.Name,
+					key:                      filename,
+					arn:                      record.S3.bucket.Arn,
+					expandEventListFromField: fs.ExpandEventListFromField,
+				})
+				break
+			}
 		}
 	}
 	return s3Infos, nil
@@ -456,7 +476,7 @@ func (p *s3Input) createEventsFromS3Info(svc s3iface.ClientAPI, info s3Info, s3C
 	}
 
 	// Decode JSON documents when content-type is "application/json" or expand_event_list_from_field is given in config
-	if resp.ContentType != nil && *resp.ContentType == "application/json" || p.config.ExpandEventListFromField != "" {
+	if resp.ContentType != nil && *resp.ContentType == "application/json" || info.expandEventListFromField != "" {
 		decoder := json.NewDecoder(reader)
 		err := p.decodeJSON(decoder, objectHash, info, s3Ctx)
 		if err != nil {
@@ -537,10 +557,10 @@ func (p *s3Input) decodeJSON(decoder *json.Decoder, objectHash string, s3Info s3
 func (p *s3Input) jsonFieldsType(jsonFields interface{}, offset int, objectHash string, s3Info s3Info, s3Ctx *s3Context) (int, error) {
 	switch f := jsonFields.(type) {
 	case map[string][]interface{}:
-		if p.config.ExpandEventListFromField != "" {
-			textValues, ok := f[p.config.ExpandEventListFromField]
+		if s3Info.expandEventListFromField != "" {
+			textValues, ok := f[s3Info.expandEventListFromField]
 			if !ok {
-				err := errors.Errorf("key '%s' not found", p.config.ExpandEventListFromField)
+				err := errors.Errorf("key '%s' not found", s3Info.expandEventListFromField)
 				p.logger.Error(err)
 				return offset, err
 			}
@@ -555,10 +575,10 @@ func (p *s3Input) jsonFieldsType(jsonFields interface{}, offset int, objectHash
 			return offset, nil
 		}
 	case map[string]interface{}:
-		if p.config.ExpandEventListFromField != "" {
-			textValues, ok := f[p.config.ExpandEventListFromField]
+		if s3Info.expandEventListFromField != "" {
+			textValues, ok := f[s3Info.expandEventListFromField]
 			if !ok {
-				err := errors.Errorf("key '%s' not found", p.config.ExpandEventListFromField)
+				err := errors.Errorf("key '%s' not found", s3Info.expandEventListFromField)
 				p.logger.Error(err)
 				return offset, err
 			}

x-pack/filebeat/input/s3/input_test.go

@@ -120,9 +120,10 @@ func TestHandleMessage(t *testing.T) {
 		},
 	}
 
+	p := &s3Input{context: &channelContext{}}
 	for _, c := range casesPositive {
 		t.Run(c.title, func(t *testing.T) {
-			s3Info, err := handleSQSMessage(c.message)
+			s3Info, err := p.handleSQSMessage(c.message)
 			assert.NoError(t, err)
 			assert.Equal(t, len(c.expectedS3Infos), len(s3Info))
 			if len(s3Info) > 0 {
@@ -155,7 +156,7 @@ func TestHandleMessage(t *testing.T) {
 
 	for _, c := range casesNegative {
 		t.Run(c.title, func(t *testing.T) {
-			s3Info, err := handleSQSMessage(c.message)
+			s3Info, err := p.handleSQSMessage(c.message)
 			assert.Error(t, err)
 			assert.Nil(t, s3Info)
 		})

x-pack/filebeat/module/aws/_meta/config.yml

@@ -5,6 +5,18 @@
     # AWS SQS queue url
     #var.queue_url: https://sqs.myregion.amazonaws.com/123456/myqueue
 
+    # Process CloudTrail logs
+    # default is true, set to false to skip Cloudtrail logs
+    # var.process_cloudtrail_logs: false
+
+    # Process CloudTrail Digest logs
+    # default true, set to false to skip CloudTrail Digest logs
+    # var.process_digest_logs: false
+
+    # Process CloudTrail Insight logs
+    # default true, set to false to skip CloudTrail Insight logs
+    # var.process_insight_logs: false
+
     # Filename of AWS credential file
     # If not set "$HOME/.aws/credentials" is used on Linux/Mac
     # "%UserProfile%\.aws\credentials" is used on Windows