ClientID regex is too restrictive.

[alexhein]

Description

The sarama client allows to set the client.id in the (producer) configuration. It is not uncommon to use symbols like '|' in the client ID string. The regex does not allow this, however. See

sarama/config.go

Line 18 in 82f0e48

var validID = regexp.MustCompile(`\A[A-Za-z0-9._-]+\z`)

[dnwe]

@alexhein yes that's interesting, I have seen for example mirror connectors use | in their generated clientIDs these days here

I believe the original validation regex was based on the one that existed in the Java clients pre-1.0.0 but KIP-190 removed the client-side validation because instead the brokers were updated to be able to cope with any clientID and sanitize it before using it in metrics

[alexhein]

@dnwe Thank you for pointing me to the KIP, I was not aware of that.