I just submitted a PR, my first for this project: https://github.com/apache/beam/pull/5983
It enables one to use the S3FileSystem from behind a filewall where you need an outbound proxy configured. I want to be able to TextIO.write().to("s3://mybucket/myfile.txt") but I can't unless I configure a proxy. With this PR you can specify the proxy configuration either via command line: --clientConfiguration{"proxyHost":"hostname","proxyPort":1234,"proxyUsername":"username","proxyPassword":"password"} Or in code: PipelineOptions options = PipelineOptionsFactory.fromArgs(args).withValidation().create(); ClientConfiguration clientConfiguration = new ClientConfiguration(); clientConfiguration.setProxyHost("hostname"); clientConfiguration.setProxyPort(1234); clientConfiguration.setProxyUsername("username"); clientConfiguration.setProxyPassword("password"); options.as(AwsOptions.class).setClientConfiguration(clientConfiguration); The PR auto selected jbonofre, lukecwik, and charmikaramj as reviewers when i created it. The contribution guide suggested that I ask here to see who else I should add as a reviewer. Please let me know who I should add as reviewers, or any other changes I should make. Thanks!!