Regex support Negative Lookahead

[marijus-ravickas]

Description

I am trying to consume topic's using regex ^nginx.(?!svc$|nginx$|.*sandbox).* and getting Local: Invalid argument or configuration (invalid_arg). How could I solve this issue? And seems I was not able to find anything useful abour regex in documentation.

How to reproduce

use ^nginx.(?!svc$|nginx$|.*sandbox).* as topic name

IMPORTANT: Always try to reproduce the issue on the latest released version (see https://github.com/edenhill/librdkafka/releases), if it can't be reproduced on the latest version the issue has been fixed.

Checklist

IMPORTANT: We will close issues where the checklist has not been completed.

Please provide the following information:

• [x] librdkafka version (release number or git tag): <REPLACE with e.g., v0.10.5 or a git sha. NOT "latest" or "current">
• [ ] Apache Kafka version: <REPLACE with e.g., 0.10.2.3>
• [ ] librdkafka client configuration: <REPLACE with e.g., message.timeout.ms=123, auto.reset.offset=earliest, ..>
• [ ] Operating system: <REPLACE with e.g., Centos 5 (x64)>
• [ ] Provide logs (with debug=.. as necessary) from librdkafka
• [ ] Provide broker log excerpts
• [ ] Critical issue

[tmcqueen-materials]

In depends on how it is compiled, but per https://github.com/edenhill/librdkafka/blob/f092c290995ca81b3afb4015fcc3350ba02caa96/src/rdregex.c#L72 librdkafka uses internally POSIX extended regular expressions. These are limited compared to PCREs and do not support lookahead/backreferences/etc.

[edenhill]

You can use topic.blacklist to filter out topics that the client should not see at all.