The full source for my example is available on github <https://github.com/jean-philippe-martin/SparkRepro>.
I'm using maven to depend on gcloud-java-nio <https://mvnrepository.com/artifact/com.google.cloud/gcloud-java-nio/0.2.5>, which provides a Java FileSystem for Google Cloud Storage, via "gs://" URLs. My Spark project uses maven-shade-plugin to create one big jar with all the source in it. The big jar correctly includes a META-INF/services/java.nio.file.spi.FileSystemProviderfile, containing the correct name for the class ( com.google.cloud.storage.contrib.nio.CloudStorageFileSystemProvider). I checked and that class is also correctly included in the jar file. The program uses FileSystemProvider.installedProviders() to list the filesystem providers it finds. "gs" should be listed (and it is if I run the same function in a non-Spark context), but when running with Spark on Dataproc, that provider's gone. I'd like to know: *How can I use a custom filesystem in my Spark program*? (asked earlier <http://stackoverflow.com/questions/39500445/filesystem-provider-disappearing-in-spark> in Stackoverflow but I didn't get any traction there)
