This is a plugin for Logstash that retrieves logs that have been written to an Azure blob storage container by the log4net.Azure appender. It is based on the input plugin example provided by Logstash and was written out of personal need, and of course comes with no guarantees. It works for me! :-)
It is fully free and fully open source. The license is Apache 2.0, meaning you are pretty much free to use it however you want in whatever way.