Filebeat kafka input using multiline parser gives no output - apache-kafka

Question

Filebeat is configured to use input from kafka and output to file
When the multiline setting is turned off, the output is published to a file.
But when kafka input is configured with mutiline, no output in the file(file is not even created)
Here is relevant filebeat configuration
Input configuration
filebeat.inputs:
- type: kafka
hosts:
- <ip>:9092
topics:
- "my-multiline-log"
group_id: "kafka-consumer-filebeat"
parsers:
- multiline:
# type: pattern
pattern: '^'
negate: true
match: after
Output Configuration:
output.file:
path: "/tmp/filebeat"
filename: filebeat
# codec.format:
# string: '%{[message]}'
Filebeat relevant logs
2021-12-16T11:02:34.551Z INFO [input.kafka] compat/compat.go:111 Input kafka starting {"id": "19A7FFEEC9EDFC04"}
2021-12-16T11:02:34.551Z INFO [input.kafka.kafka input] kafka/input.go:129 Starting Kafka input {"id": "19A7FFEEC9EDFC04", "hosts": ["<ip>:9092"]}
2021-12-16T11:02:38.158Z DEBUG [reader_multiline] multiline/pattern.go:142 Multiline event flushed because timeout reached.
2021-12-16T11:02:44.767Z DEBUG [reader_multiline] multiline/pattern.go:142 Multiline event flushed because timeout reached.
2021-12-16T11:02:51.481Z DEBUG [reader_multiline] multiline/pattern.go:142 Multiline event flushed because timeout reached.
2021-12-16T11:02:58.225Z DEBUG [reader_multiline] multiline/pattern.go:142 Multiline event flushed because timeout reached.
2021-12-16T11:03:04.555Z DEBUG cgroup/util.go:276 PID 1 contains a cgroups V2 path (0::/) but no V2 mountpoint was found.
This may be because metricbeat is running inside a container on a hybrid system.
To monitor cgroups V2 processess in this way, mount the unified (V2) hierarchy inside
the container as /sys/fs/cgroup/unified and start metricbeat with --system.hostfs.
Getting same four line of reader_multiline in the logs repeated
Edit: The support for multiline parser for kafka has been added in version 7.16