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feat(lambda-promtail): Adding S3 log parser support for AWS GuardDuty (
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samuelebstein committed Jul 24, 2024
1 parent 8434b2f commit 2d92fff
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Showing 4 changed files with 54 additions and 2 deletions.
16 changes: 15 additions & 1 deletion tools/lambda-promtail/lambda-promtail/s3.go
Original file line number Diff line number Diff line change
Expand Up @@ -50,6 +50,7 @@ const (
LB_NLB_TYPE string = "net"
LB_ALB_TYPE string = "app"
WAF_LOG_TYPE string = "WAFLogs"
GUARDDUTY_LOG_TYPE string = "GuardDuty"
)

var (
Expand All @@ -75,13 +76,18 @@ var (
// source: https://docs.aws.amazon.com/waf/latest/developerguide/logging-s3.html
// format: aws-waf-logs-suffix[/prefix]/AWSLogs/aws-account-id/WAFLogs/region/webacl-name/year/month/day/hour/minute/aws-account-id_waflogs_region_webacl-name_timestamp_hash.log.gz
// example: aws-waf-logs-test/AWSLogs/11111111111/WAFLogs/us-east-1/TEST-WEBACL/2021/10/28/19/50/11111111111_waflogs_us-east-1_TEST-WEBACL_20211028T1950Z_e0ca43b5.log.gz
// AWS GuardDuty
// source: https://docs.aws.amazon.com/guardduty/latest/ug/guardduty_exportfindings.html
// format: my-bucket/AWSLogs/aws-account-id/GuardDuty/region/year/month/day/random-string.jsonl.gz
// example: my-bucket/AWSLogs/123456789012/GuardDuty/us-east-1/2024/05/30/07a3f2ce-1485-3031-b842-e1f324c4a48d.jsonl.gz
defaultFilenameRegex = regexp.MustCompile(`AWSLogs\/(?P<account_id>\d+)\/(?P<type>[a-zA-Z0-9_\-]+)\/(?P<region>[\w-]+)\/(?P<year>\d+)\/(?P<month>\d+)\/(?P<day>\d+)\/\d+\_(?:elasticloadbalancing|vpcflowlogs)_(?:\w+-\w+-(?:\w+-)?\d)_(?:(?P<lb_type>app|net)\.*?)?(?P<src>[a-zA-Z0-9\-]+)`)
defaultTimestampRegex = regexp.MustCompile(`(?P<timestamp>\d+-\d+-\d+T\d+:\d+:\d+(?:\.\d+Z)?)`)
cloudtrailFilenameRegex = regexp.MustCompile(`AWSLogs\/(?P<organization_id>o-[a-z0-9]{10,32})?\/?(?P<account_id>\d+)\/(?P<type>[a-zA-Z0-9_\-]+)\/(?P<region>[\w-]+)\/(?P<year>\d+)\/(?P<month>\d+)\/(?P<day>\d+)\/\d+\_(?:CloudTrail|CloudTrail-Digest)_(?:\w+-\w+-(?:\w+-)?\d)_(?:(?:app|nlb|net)\.*?)?.+_(?P<src>[a-zA-Z0-9\-]+)`)
cloudfrontFilenameRegex = regexp.MustCompile(`(?P<prefix>.*)\/(?P<src>[A-Z0-9]+)\.(?P<year>\d+)-(?P<month>\d+)-(?P<day>\d+)-(.+)`)
cloudfrontTimestampRegex = regexp.MustCompile(`(?P<timestamp>\d+-\d+-\d+\s\d+:\d+:\d+)`)
wafFilenameRegex = regexp.MustCompile(`AWSLogs\/(?P<account_id>\d+)\/(?P<type>WAFLogs)\/(?P<region>[\w-]+)\/(?P<src>[\w-]+)\/(?P<year>\d+)\/(?P<month>\d+)\/(?P<day>\d+)\/(?P<hour>\d+)\/(?P<minute>\d+)\/\d+\_waflogs\_[\w-]+_[\w-]+_\d+T\d+Z_\w+`)
wafTimestampRegex = regexp.MustCompile(`"timestamp":\s*(?P<timestamp>\d+),`)
guarddutyFilenameRegex = regexp.MustCompile(`AWSLogs\/(?P<account_id>\d+)\/(?P<type>GuardDuty)\/(?P<region>[\w-]+)\/(?P<year>\d+)\/(?P<month>\d+)\/(?P<day>\d+)\/.+`)
parsers = map[string]parserConfig{
FLOW_LOG_TYPE: {
logTypeLabel: "s3_vpc_flow",
Expand Down Expand Up @@ -122,6 +128,14 @@ var (
timestampRegex: wafTimestampRegex,
timestampType: "unix",
},
GUARDDUTY_LOG_TYPE: {
logTypeLabel: "s3_guardduty",
filenameRegex: guarddutyFilenameRegex,
ownerLabelKey: "account_id",
timestampFormat: time.RFC3339,
timestampRegex: defaultTimestampRegex,
timestampType: "string",
},
}
)

Expand Down Expand Up @@ -165,7 +179,7 @@ func parseS3Log(ctx context.Context, b *batch, labels map[string]string, obj io.
ls = applyLabels(ls)

// extract the timestamp of the nested event and sends the rest as raw json
if labels["type"] == CLOUDTRAIL_LOG_TYPE {
if labels["type"] == CLOUDTRAIL_LOG_TYPE || labels["type"] == GUARDDUTY_LOG_TYPE {
records := make(chan Record)
jsonStream := NewJSONStream(records)
go jsonStream.Start(gzreader, parser.skipHeaderCount)
Expand Down
32 changes: 32 additions & 0 deletions tools/lambda-promtail/lambda-promtail/s3_test.go
Original file line number Diff line number Diff line change
Expand Up @@ -93,6 +93,38 @@ func Test_getLabels(t *testing.T) {
},
wantErr: false,
},
{
name: "s3_guardduty",
args: args{
record: events.S3EventRecord{
AWSRegion: "us-east-1",
S3: events.S3Entity{
Bucket: events.S3Bucket{
Name: "s3_guardduty_test",
OwnerIdentity: events.S3UserIdentity{
PrincipalID: "test",
},
},
Object: events.S3Object{
Key: "AWSLogs/123456789012/GuardDuty/us-east-1/2024/05/30/07a3f2ce-1485-3031-b842-e1f324c4a48d.jsonl.gz",
},
},
},
},
want: map[string]string{
"account_id": "123456789012",
"bucket": "s3_guardduty_test",
"bucket_owner": "test",
"bucket_region": "us-east-1",
"day": "30",
"key": "AWSLogs/123456789012/GuardDuty/us-east-1/2024/05/30/07a3f2ce-1485-3031-b842-e1f324c4a48d.jsonl.gz",
"month": "05",
"region": "us-east-1",
"type": GUARDDUTY_LOG_TYPE,
"year": "2024",
},
wantErr: false,
},
{
name: "s3_flow_logs",
args: args{
Expand Down
2 changes: 1 addition & 1 deletion tools/lambda-promtail/main.tf
Original file line number Diff line number Diff line change
Expand Up @@ -251,7 +251,7 @@ resource "aws_s3_bucket_notification" "this" {
lambda_function_arn = aws_lambda_function.this.arn
events = ["s3:ObjectCreated:*"]
filter_prefix = "AWSLogs/"
filter_suffix = ".log.gz"
filter_suffix = var.filter_suffix
}

depends_on = [
Expand Down
6 changes: 6 additions & 0 deletions tools/lambda-promtail/variables.tf
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,12 @@ variable "bucket_names" {
default = []
}

variable "filter_suffix" {
type = string
description = "Suffix for S3 bucket notification filter"
default = ".gz"
}

variable "log_group_names" {
type = set(string)
description = "List of CloudWatch Log Group names to create Subscription Filters for."
Expand Down

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