ZOOKEEPER-4303: Allow configuring client port to 0

[madrob]

https://issues.apache.org/jira/browse/ZOOKEEPER-4303

Allows specifying an explicit port 0 for the client port or secure client port, which will default to operating system behavior of finding an unbound port. Modified ZKServerEmbedded to report the actual port instead of the configured port.

[madrob]

I'm not able to reproduce the failure seen by the GitHub actions, can somebody help me figure out if this is caused by my changes or an existing issue?

[madrob]

Force pushed rebase to development branch.

[eolivelli]

I have restarted CI

[kezhuw]

@maoling @symat Could you please take a look at this ? It is valuable in testing/embedded environments to avoid port conflict. It is ZooKeeper's CURATOR-535.

[kezhuw]

@eolivelli @symat Shall we merge this ?

[symat]

sorry for the delay, I kind of forgot about this one, I can merge it :( @eolivelli - can I merge this or do we need an other test run here? (is there any way to re-trigger the failing pr-merge jenkins job? - I don't even remember which one is that or if it is important)

[eolivelli]

I think that we can merge it. you could restart the job by logging into jenkins using your ASF credentials.

I believe it is useless now that we have GH actions, I already started a discussion on dev@

[symat]

yes, I agree to eliminate some of these CI jobs. I'll merge this PR now.

[symat]

merge is done, thank you @madrob for your contribution! and for your patience ;)

[kezhuw]

@eolivelli @symat Would you mind merging this to 3.7 and 3.8 ? apache/curator#421 needs this.