"SSL_connect returned=1 errno=0 state=error: certificate verify failed (EE certificate key too weak)"

[ZhongPengQun2]

What happened:

# cat /etc/fluent/fluent-2.conf
<match **>
  @type splunk_hec
  hec_host 139.196.3.1
  hec_port 18088
  hec_token BF4736E9-474D-40A6-SECRET-410E1F4662E1
</match>

Then start fluentd

fluentd -c /etc/fluent/fluent-2.conf

but get ssl error

2023-03-19 15:08:40 +0000 [warn]: #0 suppressed same stacktrace
2023-03-19 15:13:13 +0000 [warn]: #0 failed to flush the buffer. retry_times=9 next_retry_time=2023-03-19 15:21:03 +0000 chunk="5f7421cd75ec3e281d2ee436e29d9ad4" error_class=OpenSSL::SSL::SSLError error="SSL_connect returned=1 errno=0 state=error: certificate verify failed (EE certificate key too weak)"
  2023-03-19 15:13:13 +0000 [warn]: #0 suppressed same stacktrace
2023-03-19 15:21:03 +0000 [warn]: #0 failed to flush the buffer. retry_times=10 next_retry_time=2023-03-19 15:39:46 +0000 chunk="5f7421cd75ec3e281d2ee436e29d9ad4" error_class=OpenSSL::SSL::SSLError error="SSL_connect returned=1 errno=0 state=error: certificate verify failed (EE certificate key too weak)"
  2023-03-19 15:21:03 +0000 [warn]: #0 suppressed same stacktrace

What you expected to happen:
Splunk receives log

How to reproduce it (as minimally and precisely as possible): (it may lose efficacy)

docker run zhongpengqun/ruby:2.7.4-with-fluent-plugin-splunk-hec

Then in container and execute below command

fluentd -c /etc/fluent/fluent-2.conf

Anything else we need to know?:

Environment:

• Kubernetes version (use kubectl version):
  1.23
• Ruby version (use ruby --version):
  ruby 2.7.4p191
• OS (e.g: cat /etc/os-release):
  debian 11
• Splunk version:
  6.3.3 trial edition