[fix][broker] Fix create cluster with empty url

[nodece]

Motivation

When creating the cluster, if the serviceUrlTls is empty in the ClusterData, I got Illegal service tls url, example: https://pulsar.example.com:8443. I expect the Pulsar works fine.

#19151 breaks this behavior, see the following code:

    public static void checkURIIfPresent(@Nullable String uri,
                                         @Nonnull Predicate<URI> predicate,
                                         @Nullable String errorMessage) throws IllegalArgumentException {
        if (uri == null) {
            return;
        }
        checkURI(uri, predicate, errorMessage);
    }

This check should also ignore the empty URL.

Modifications

• Ignore checking the empty URL

Verifying this change

• Make sure that the change passes the CI checks.

Added testCreateCluster test.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

[nodece]

/pulsarbot rerun-failure-checks

[nodece]

/pulsarbot rerun-failure-checks

[Technoboy-]

/pulsarbot rerun-failure-checks

[Technoboy-]

/pulsarbot rerun-failure-checks

[Technoboy-]

/pulsarbot rerun-failure-checks

[michaeljmarshall]

I think one risk here is that it is now possible to create a cluster with all empty cluster urls. I think it might make sense to verify that there is some URL that is not zero length.

Additionally, one benefit of this change is for clusters that only want to supply a TLS url.

What is your opinion @nodece?

[nodece]

I think one risk here is that it is now possible to create a cluster with all empty cluster urls. I think it might make sense to verify that there is some URL that is not zero length.

Sure, I agreed with you! We must ensure that at least one URL is a non-zero length when creating the cluster.

Do you make a PR to do that? Recently, I don't have time to maintain the Pulsar :(

[nodece]

@michaeljmarshall

[michaeljmarshall]

I'll create a GitHub issue and label it as a good one for first time contributors.

[michaeljmarshall]

I created #19866.

Also, while looking into it, I realized that this PR didn't introduce the possibility of configuring no urls. The issue I created is very low priority.