WebHCat is a web-based REST API for HCatalog, a management layer for dealing with files in HDFS. If you’re looking for configuration settings for WebHCat, you’ll want generally to look for “templeton” in config files, as Templeton was the project name before WebHCat. In Ambari, you can go to the Hive configs and look at webhcat-site.xml for configuration settings. For WebHCat, the default port in HDInsight is 30111, which you should find in the templeton.port configuration setting.
I don’t like the fact that WebHDFS is blocked, but at least WebHCat is functional.