Fluent Bit does not send close_notify on SSL Forward

[drbugfinder-work]

Bug Report

Describe the bug
We are using Fluent Bit that forwards messages to a FluentD instance via Forward protocol.

With the use of fluentd (td-agent) on the newer Ubuntu 22.04, which uses OpenSSL 3 now, instead of OpenSSL 1.1.1, we are receiving warnings on fluentd side:

│ 2022-07-25 09:09:34 +0000 [warn]: #0 close socket due to unexpected ssl error: SSL_read: unexpected eof while reading
│ 2022-07-25 09:09:42 +0000 [warn]: #0 close socket due to unexpected ssl error: SSL_read: unexpected eof while reading

As mentioned here fluent/fluentd#3833 (comment), it looks like Fluent Bit does not send close_notify alerts on connection shutdown. This leads into the warnings on the receiver side.

To Reproduce

• Set up Fluent Bit and Fluentd
• Create config for forwarding messages from Fluent Bit to Fluentd via SSL Forward
• See warnings in Fluentd logs

Expected behavior
No SSL warnings

Your Environment

• Version used: Fluent Bit 1.9.6
• Environment name and version (e.g. Kubernetes? What version?): Kubernetes v1.23.4
• Operating System and version: Ubuntu 22.04
• Filters and plugins: Input File, Output Forward

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 5 days. Maintainers can add the exempt-stale label.

[drbugfinder-work]

still existing in Fluent Bit 1.9.9

[github-actions]

This issue is stale because it has been open 90 days with no activity. Remove stale label or comment or this will be closed in 5 days. Maintainers can add the exempt-stale label.

[github-actions]

This issue was closed because it has been stalled for 5 days with no activity.