v4.0.5

Next generation Telemetry Agent for Logs, Metrics and Traces.

July 22, 2025

KNOWLEDGE BASE

Release Notes v4.0.5

Fluent Bit is a Fast and Lightweight Data Processor and Forwarder for Linux, BSD, Windows and macOS. We are proud to announce the availability of Fluent Bit v4.0.5.

Below is a detailed list of changes included in this release…

What’s new ?


Core


  • aws: restore IMDS timeouts after upstream_set in EC2 provider (PR #10637)
  • upstream: add new net.proxy_env_ignore variable (PR #10638)
  • network
    • enable EDNS for DNS queries to support large responses (PR #10589)
  • tls
    • openssl: Make configurable certstore name (PR #10640)
    • openssl: Add setting up interface for certstore (PR #10640)
  • output
    • Load CertStore with a user-defined store name (PR #10640)
    • Add debug messages for loading certificates from certstore (PR #10640)
  • pack
    • Handle UINT_MAX value correctly (PR #10640)
    • tests: Add test cases for INT_MAX and UINT_MAX cases for json packing (PR #10640)

Plugins


Contributors

On every release, there are many people involved doing contributions on different areas like bug reporting, troubleshooting, documentation and coding, without these contributions from the community, the project won’t be the same and won’t be in the good shape that it is now. So THANK YOU! to everyone who takes part of this journey!

Join us

We want to hear about you, our community is growing and you can be part of it!, you can contact us at:

Latest Version

New release on July 22, 2025

Fluent Bit v4.0.5 is out!

Check out the Release Notes, read the Updated Documentation or jump directly to the Downloads Section.

We are part of a wide community, no vendor lock-in.