segfault on `\RdKafka\Metadata\Topic::getTopic()`

[ctrl-f5]

We have the following code running during deploy to verify required kafka topics exist:

$consumer = new \RdKafka\KafkaConsumer(); // this is built up elsewhere
$existingTopics = $consumer
    ->getMetadata(true, null, 1000)
    ->getTopics();

foreach ($existingTopics as $topic) {
    $this->availableTopicsInKafka[] = $topic->getTopic();
}

Which works perfectly on 7.4.x but fails consistently on 8.0-alpine with a segementation fault on the first call to $topic->getTopic().

Segmentation fault (core dumped)

I tried enabling librdkafka logs and debug but it doesnt output anything.

PHP Version => 8.0.9

System => Linux 81bdef77c496 5.11.0-27-generic #29~20.04.1-Ubuntu SMP Wed Aug 11 15:58:17 UTC 2021 x86_64

rdkafka support => enabled
version => 5.0.0
build date => Sep  3 2021 09:45:22
librdkafka version (runtime) => 1.7.0
librdkafka version (build) => 1.7.0.255

[rafelangelo]

We face the same problem while migrating vom 7.4 to 8.0 on Alpine 3.13. It is possible to do a count() on the RdKafka\Metadata\Collection, but accessing the items is not possible.

PHP 8.0.10 (cli) (built: Sep  1 2021 04:23:01) ( NTS )

rdkafka

rdkafka support => enabled
version => 5.0.0
build date => Sep  2 2021 22:08:41
librdkafka version (runtime) => 1.7.0
librdkafka version (build) => 1.7.0.255

[dirx]

Hi @ctrl-f5, after some testing - looks like keeping $metadata seems to work for us as workaround:

$consumer = new \RdKafka\KafkaConsumer(); // this is built up elsewhere
$metadata = $consumer->getMetadata(true, null, 1000);

foreach ($metadata->getTopics() as $topic) {
    $this->availableTopicsInKafka[] = $topic->getTopic();
}

[arnaud-lb]

Thanks @ctrl-f5 @rafelangelo @dirx

This should be fixed by #477