Envoy validate mode not working with envoy.access_loggers.fluentd extension

[dceravigupta]

Title: Envoy validate mode not working with fluentd access logger extension

Description:

I was trying out the new fluentd access logger extension which got recently added into envoy but after making configuration changes, envoy validation mode stops working and started throwing a Segmentation fault. Given the configuration is working fine in live mode, it seems to me like a issue with the validation mode itself.
envoyfluentd.json

Repro steps:

Download the envoyfluentd.json config file and try to validate by running `envoy --mode validate -c envoyfluentd.json'

Config:

envoyfluentd.json

Logs:

[2024-07-08 11:43:30.411][117546][info][config] [source/server/configuration_impl.cc:168] loading tracing configuration
[2024-07-08 11:43:30.411][117546][info][config] [source/server/configuration_impl.cc:124] loading 0 static secret(s)
[2024-07-08 11:43:30.411][117546][info][config] [source/server/configuration_impl.cc:130] loading 5 cluster(s)
[2024-07-08 11:43:30.533][117546][info][config] [source/server/configuration_impl.cc:138] loading 1 listener(s)
[2024-07-08 11:43:30.551][117546][critical][backtrace] [./source/server/backtrace.h:127] Caught Segmentation fault, suspect faulting address 0x0
[2024-07-08 11:43:30.551][117546][critical][backtrace] [./source/server/backtrace.h:111] Backtrace (use tools/stack_decode.py to get line numbers):
[2024-07-08 11:43:30.551][117546][critical][backtrace] [./source/server/backtrace.h:112] Envoy version: d79f6e8/1.30.2/Clean/RELEASE/BoringSSL
[2024-07-08 11:43:30.553][117546][critical][backtrace] [./source/server/backtrace.h:114] Address mapping: 5633dec10000-5633e15b8000 //envoy_1.30.2
[2024-07-08 11:43:30.553][117546][critical][backtrace] [./source/server/backtrace.h:119] #0: __restore_rt [0x7f9dca2a7420]
[2024-07-08 11:43:30.568][117546][critical][backtrace] [./source/server/backtrace.h:121] #1: [0x5633dec46792]
[2024-07-08 11:43:30.575][117546][critical][backtrace] [./source/server/backtrace.h:121] #2: [0x5633dec48e86]
[2024-07-08 11:43:30.582][117546][critical][backtrace] [./source/server/backtrace.h:121] #3: [0x5633e05950a8]
[2024-07-08 11:43:30.588][117546][critical][backtrace] [./source/server/backtrace.h:121] #4: [0x5633dec468ef]
[2024-07-08 11:43:30.594][117546][critical][backtrace] [./source/server/backtrace.h:121] #5: [0x5633dec43f5d]
[2024-07-08 11:43:30.600][117546][critical][backtrace] [./source/server/backtrace.h:121] #6: [0x5633dec42790]
[2024-07-08 11:43:30.606][117546][critical][backtrace] [./source/server/backtrace.h:121] #7: [0x5633e0c038bb]
[2024-07-08 11:43:30.611][117546][critical][backtrace] [./source/server/backtrace.h:121] #8: [0x5633e0b9ce90]
[2024-07-08 11:43:30.617][117546][critical][backtrace] [./source/server/backtrace.h:121] #9: [0x5633df1704bb]
[2024-07-08 11:43:30.623][117546][critical][backtrace] [./source/server/backtrace.h:121] #10: [0x5633df170ac2]
[2024-07-08 11:43:30.629][117546][critical][backtrace] [./source/server/backtrace.h:121] #11: [0x5633df170cb2]
[2024-07-08 11:43:30.635][117546][critical][backtrace] [./source/server/backtrace.h:121] #12: [0x5633e0b16c8a]
[2024-07-08 11:43:30.642][117546][critical][backtrace] [./source/server/backtrace.h:121] #13: [0x5633e0b117b8]
[2024-07-08 11:43:30.648][117546][critical][backtrace] [./source/server/backtrace.h:121] #14: [0x5633e0b0f91e]
[2024-07-08 11:43:30.654][117546][critical][backtrace] [./source/server/backtrace.h:121] #15: [0x5633e0b0c3e5]
[2024-07-08 11:43:30.661][117546][critical][backtrace] [./source/server/backtrace.h:121] #16: [0x5633e0b0c572]
[2024-07-08 11:43:30.667][117546][critical][backtrace] [./source/server/backtrace.h:121] #17: [0x5633e0b0c4f9]
[2024-07-08 11:43:30.672][117546][critical][backtrace] [./source/server/backtrace.h:121] #18: [0x5633e0b12b7e]
[2024-07-08 11:43:30.680][117546][critical][backtrace] [./source/server/backtrace.h:121] #19: [0x5633e0a9e63f]
[2024-07-08 11:43:30.686][117546][critical][backtrace] [./source/server/backtrace.h:121] #20: [0x5633e0a81e4b]
[2024-07-08 11:43:30.693][117546][critical][backtrace] [./source/server/backtrace.h:121] #21: [0x5633e0aad016]
[2024-07-08 11:43:30.699][117546][critical][backtrace] [./source/server/backtrace.h:121] #22: [0x5633e0aacb29]
[2024-07-08 11:43:30.704][117546][critical][backtrace] [./source/server/backtrace.h:121] #23: [0x5633e0ac47bc]
[2024-07-08 11:43:30.709][117546][critical][backtrace] [./source/server/backtrace.h:121] #24: [0x5633e0a8df0a]
[2024-07-08 11:43:30.715][117546][critical][backtrace] [./source/server/backtrace.h:121] #25: [0x5633e0aa7b96]
[2024-07-08 11:43:30.723][117546][critical][backtrace] [./source/server/backtrace.h:121] #26: [0x5633e0aa6699]
[2024-07-08 11:43:30.729][117546][critical][backtrace] [./source/server/backtrace.h:121] #27: [0x5633e0bfeabb]
[2024-07-08 11:43:30.736][117546][critical][backtrace] [./source/server/backtrace.h:121] #28: [0x5633e0582b23]
[2024-07-08 11:43:30.743][117546][critical][backtrace] [./source/server/backtrace.h:121] #29: [0x5633e0580f2e]
[2024-07-08 11:43:30.748][117546][critical][backtrace] [./source/server/backtrace.h:121] #30: [0x5633e058022e]
[2024-07-08 11:43:30.753][117546][critical][backtrace] [./source/server/backtrace.h:121] #31: [0x5633e054ffcb]
[2024-07-08 11:43:30.760][117546][critical][backtrace] [./source/server/backtrace.h:121] #32: [0x5633e055076e]
[2024-07-08 11:43:30.765][117546][critical][backtrace] [./source/server/backtrace.h:121] #33: [0x5633dec1014c]
[2024-07-08 11:43:30.766][117546][critical][backtrace] [./source/server/backtrace.h:119] #34: __libc_start_main [0x7f9dca0c5083]
Segmentation fault

Note: If there are privacy concerns, sanitize the data prior to
sharing.

Call Stack:

If the Envoy binary is crashing, a call stack is required.
Please refer to the Bazel Stack trace documentation.

[dceravigupta]

fyi: @ohadvano

[ohadvano]

/assign @ohadvano

[nezdolik]

cc @wbpcode

[dceravigupta]

Thanks @ohadvano!