Authentication failure when running hbase-spark in local mode

Problem

When running Spark in local mode, hbase-spark fails to authenticate to a Kerberos secured HBase cluster. The error message is:

No matching SASL authentication provider and supporting token found from providers for user: xxx@XXX.XXX (auth:PROXY)

That is because applyCreds changes the authentication method of the current user to PROXY, when it should still be KERBEROS for local mode to run correctly.

Suggested solution

To fix this, I propose removing applyCreds. The function is no longer needed and should be removed:

1. Because we should not change the authentication mode of the current user in local mode
2. And because the purpose of the function is no longer valid. It is not doing anything meaningful since the broadcasting of the user credentials was removed in this commit:
https://github.com/apache/hbase-connectors/commit/75e41365207408f5b47d5925469a49fd60078b5e

A pull request is on the way.

Testing

The fix was manually tested against Kerberos secured HBase 2.4.17 + Hadoop 3.3.5 cluster using Spark 3.5.1, both in local mode and with Yarn master, running the following Python code.

df = (spark.read.format("org.apache.hadoop.hbase.spark")
                .option("hbase.columns.mapping", "key STRING :key, state STRING info:state")
                .option("hbase.table", "hbase:meta").load())
df.first()