envoyproxy/envoy

HTTP access log formatters for dynamic metadata written by Listener/Network level filters

Open

#41,116 opened on Sep 17, 2025

View on GitHub
 (2 comments) (1 reaction) (0 assignees)C++ (5,373 forks)batch import
area/access_loghelp wanted

Repository metrics

Stars
 (27,997 stars)
PR merge metrics
 (Avg merge 8d) (378 merged PRs in 30d)

Description

Description: It is a known issue currently that dynamic metadata written at the listener/network scope is not available to the HTTP access logger. Any HTTP access log formatters that address to a namespace/keypair written by these filters ends up not being available. (See https://github.com/envoyproxy/envoy/issues/19046)

The underlying cause is that the HTTP filter manager does not copy dynamic metadata from the network over to to the stream info object, but does copy filter state (See reference here). I am wondering if this was intentional or an oversight?

What does the community recommend going forward if one has a use case for HTTP logging these fields?

  • Should these filters just use FilterState object and implement reflection/serialization, similar to this?
  • Should dynamic metadata be copied over to the HTTP filter manager stream info?

[optional Relevant Links:]

Contributor guide

Research direction
Examine the HTTP filter manager's stream info construction to understand why dynamic metadata from network filters is not copied. Compare with filter state copying logic around line 1179 in filter manager.h. Consider proposing a fix that copies dynamic metadata similarly.
Tech stack
cpp
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Clear
Prerequisites
C++Envoy internals
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20