Ignore ServFail / NxDomain for search list, e.g. in Kubernetes cluster

[roquie]

Any requests called with amphp/http-client will use these dns package. Where requests will sent inside kubernetes cluster it fails with following reason:

In Rfc1035StubResolver.php line 193:

  All query attempts failed for {{ADDRESS}}-prod.svc.cluster.l
  ocal: Server returned error code: 3, Server returned error code: 3


In functions.php line 534:

  Multiple errors encountered; use Amp\MultiReasonException::getReasons() to
  retrieve the array of exceptions thrown

Requests from pod to pod inside a same namespace in Kubernetes cluster by service name (kubectl get svc). If using local ip address instead of dns it works. But this workaround is not possible for all cases.

I think this is critical issue because a lot of many users use Kubernetes every day.

PHP: 7.4.5
amphp/amp: v2.4.4
amphp/dns: v1.2.1
amphp/http-client: v4.2.2
OS: Alpine

UV extension installed from pecl.

[roquie]

#41

[kelunik]

I haven't used Kubernetes, yet. How does DNS resolution work there? What's different?

[roquie]

Sorry for long answer. On next week I will be again works with amphp/dns and try to run series of tests in cluster. Before this bug I should fix the issue with amphp/postgres because it blocks my work.

[roquie]

• 1.2.1 does not work in cluster with global available addresses (tested github.com and api.telegram.org), but 0.9.15 works fine.
• 0.9.15 also does not work with local domain names in kubernetes cluster
• 1.1.0 works same as 0.9.15

In all cases gethostbyname returns ip.

UPD:
For 1.2.1 version this hack not help me. #82

/etc/resolv.conf

cat /etc/resolv.conf
nameserver 172.17.0.10
search calcifer-dev.svc.cluster.local svc.cluster.local cluster.local
options ndots:5

I'm trying to find some bugs in PR #89 ...

[kelunik]

What's the error message you get for github.com?

[roquie]

[kelunik]

Please retry with 8cf2ccc / latest dev-master.

[roquie]

Yes, that works in all cases. Thanks! :)

[kelunik]

Thanks for testing! Tagged as v1.2.2.