Setting Up an SFTP Server Using Elixir and Erlang

Max Mulatz and Andreas Knöpfle detail the process of integrating SFTP (Secure File Transfer Protocol) with an Elixir application, despite initial reservations about stepping outside their normal tooling. They were pleasantly surprised to discover the Erlang ecosystem could provide what they needed with little effort. The authors realized that while there is ample documentation for SFTP clients in Elixir, SFTP servers are less discussed, motivating them to share their findings. They elucidate the necessity of having an SFTP server, even in times of HTTP/2 - to interact with legacy systems and establish a mock server to emulate external systems interactions for development and testing. A step-by-step tutorial follows, using Erlang's robust `:ssh` application to set up the SSH daemon and start an SFTP subsystem within it. They provide detailed instructions, from starting the Erlang ssh daemon to authentication mechanisms and subsystem configuration. Additionally, they offer insights into configuring the SFTP client communication, other authentication methods, and additional resources. The post is rounded off with a call for readers interested in working with Elixir to consider job opportunities at bitcrowd, highlighting their appreciation for the language and its ecosystem.