LogStash concat Filebeat input - logstash

Question

I am trying to merge filebeat messages in LogStash.
I have the next Log file:
----------- SCAN SUMMARY -----------
Known viruses: 8520944
Engine version: 0.102.4
Scanned directories: 408
Scanned files: 1688
Infected files: 0
Total errors: 50
Data scanned: 8.93 MB
Data read: 4.42 MB (ratio 2.02:1)
Time: 22.052 sec (0 m 22 s)
I read it from Filebeat and send to LogStash.
The problem is that I received in LogStash each line in different message. I want to merge it all, and also add a new field that is "received_at", from the fileBeat input.
I would like to have the next output from LogStash:
{
Known_viruses: 8520944
Engine_version: 0.102.4
Scanned_directories: 408
Scanned_files: 1688
Infected_files: 0
Total_errors: 50
Data_scanned: 8.93MB
Data_read: 4.42MB
Time: 22.052sec (0 m 22 s)
Received_at: <timeStamp taked from filebeat received JSON message>
}
The input I received in LogStash from Filebeat is the next per each line:
{
"#timestamp": "2021-04-20T08:03:33.843Z",
"#version": "1",
"tags": ["beats_input_codec_plain_applied"],
"host": {
"name": "PRLN302",
"architecture": "x86_64",
"ip": ["10.126.40.18", "fe80::7dbf:4941:cd39:c0f9", "172.17.0.1", "fe80::42:82ff:fe2b:895", "fe80::24b2:8cff:feeb:20b4", "172.18.0.1", "fe80::42:53ff:fe31:a025", "fe80::b420:e1ff:fe97:c152", "fe80::9862:21ff:fe3a:c33e", "fe80::48a6:70ff:fec2:60d6", "192.168.126.117", "fe80::2831:c644:33d5:321"],
"id": "a74e193a551f4d379f9488b80a463581",
"os": {
"platform": "ubuntu",
"version": "20.04.2 LTS (Focal Fossa)",
"family": "debian",
"name": "Ubuntu",
"type": "linux",
"codename": "focal",
"kernel": "5.8.0-49-generic"
},
"mac": ["e8:6a:64:32:fe:4d", "dc:8b:28:4a:c8:88", "02:42:82:2b:08:95", "26:b2:8c:eb:20:b4", "02:42:53:31:a0:25", "b6:20:e1:97:c1:52", "9a:62:21:3a:c3:3e", "4a:a6:70:c2:60:d6", "00:50:b6:b9:19:d7"],
"containerized": false,
"hostname": "PRLN302"
},
"message": "----------- SCAN SUMMARY -----------",
"agent": {
"ephemeral_id": "ad402f64-ab73-480c-b6de-4af6184f012c",
"type": "filebeat",
"version": "7.12.0",
"id": "f681d775-d452-490a-9b8b-036466a87d35",
"name": "PRLN302",
"hostname": "PRLN302"
},
"input": {
"type": "log"
},
"ecs": {
"version": "1.8.0"
},
"log": {
"offset": 0,
"file": {
"path": "/var/log/clamav-test.log"
}
}
}
Could it be possible?

Answer 1

It is possible, you'll need to look for the multiline messages in the filebeat input:
https://www.elastic.co/guide/en/beats/filebeat/current/multiline-examples.html
somthing like below would do it i think:
multiline.type: pattern
multiline.pattern: '^----------- SCAN SUMMARY -----------'
multiline.negate: true
multiline.match: after