Skip to content

SIGSEGV on Loki output when using $TAG for labels #3290

Closed
@slobodangacesa

Description

Bug Report

Describe the bug
If I use $TAG in labels for loki output, I get SIGSEGV
I have tried docker and 'native' app, 1.7.2 and 1.7.0. In any case result is the same.
If I replace $TAG with static string or ${env_var} everything works as expected.

To Reproduce

  • sample config:
[INPUT]
    Name        dummy
    Tag         testapp
[OUTPUT]
    Name    loki
    Match   *
    host    lokihost
    labels  job=$TAG
  • Steps to reproduce the problem:
    fluent-bit -c sample.conf

  • Sample output:

Fluent Bit v1.7.2
* Copyright (C) 2019-2021 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2021/03/26 12:29:18] [ info] [engine] started (pid=1)
[2021/03/26 12:29:18] [ info] [storage] version=1.1.1, initializing...
[2021/03/26 12:29:18] [ info] [storage] in-memory
[2021/03/26 12:29:18] [ info] [storage] normal synchronization mode, checksum disabled, max_chunks_up=128
[2021/03/26 12:29:18] [ info] [output:loki:loki.0] configured, hostname=lokihost:3100
[2021/03/26 12:29:18] [ info] [sp] stream processor started
[2021/03/26 12:29:23] [engine] caught signal (SIGSEGV)
#0  0x5630ec26cc4a      in  flb_ra_get_kv_pair() at src/flb_record_accessor.c:613
#1  0x5630ec26e83c      in  flb_mp_accessor_keys_remove() at src/flb_mp.c:450
#2  0x5630ec2ccc02      in  pack_record() at plugins/out_loki/loki.c:819
#3  0x5630ec2cd396      in  loki_compose_payload() at plugins/out_loki/loki.c:1035
#4  0x5630ec2cd456      in  cb_loki_flush() at plugins/out_loki/loki.c:1062
#5  0x5630ec2464da      in  output_pre_cb_flush() at include/fluent-bit/flb_output.h:466
#6  0x5630ec6e4fc6      in  co_init() at lib/monkey/deps/flb_libco/amd64.c:117
#7  0xffffffffffffffff  in  ???() at ???:0

Expected behavior
to work

Your Environment

  • Version used:1.7.2
  • Configuration: included above ^
  • Operating System and version: Ubuntu20.04 or docker image
  • Filters and plugins: loki output

Metadata

Assignees

Type

No type

Projects

No projects

Milestone

No milestone

Relationships

None yet

Development

No branches or pull requests

Issue actions