SftpEx

An Elixir wrapper around the Erlang SFTP application. This allows for the use of Elixir Streams to transfer files via SFTP.

Installation

If available in Hex, the package can be installed as:

Add sftp_ex to your list of dependencies in mix.exs and mix deps.get from a terminal:

def deps do
  [{:sftp_ex, "~> 0.3.0"}]
end

Configurable otions

config :sftp_ex, :host, "sftp.your.server.com" # no default
config :sftp_ex, :user, "mr_anderson" # no default
config :sftp_ex, :port, 2337 # defaults to 22
config :sftp_ex, :cert, "fake" # no default and you should inject this value
config :sftp_ex, :password, "worst_password_ever" # no default and you should inject this value
config :sftp_ex, :key_cb, YourKeyProvider # only change this if you know what you're doing and you want to handle your key provider yourself
config :sftp_ex, :timeout, 60_000 # defaults to 3_600_000 (an hour), you can set it to :infinity if you really want to

Creating a Connection

The following is an example of creating a connection with a username and password.

{:ok, connection} = SftpEx.connect([host: "somehost", user: "someuser", password: "somepassword"])

or

You could put all of these values in config and load them at runtime and start with no args.

{:ok, connection} = SftpEx.connect()

Do not put sensitive information in configs such as passwords or certs. Instead use a file which is not committed to your repo or a secret holding service like Vault. Then you can inject these values at runtime using Application.put_env/2

Other connection arguments can be found in the Erlang documentation

Concepts

For some operations you'll need a file handle. To get one use open/3

SftpEx.open( conn, "remote_path")

Most things that one would think should have a timeout have a timeout. You can use the default one or your own timeout set in config and/or you can put it as an optional final arguent in most function calls.

Streaming Files

An example of writing a file to a server is the following.

stream = 
  File.stream!("filename.txt")
  |> Stream.into(SftpEx.stream!(connection,"/home/path/filename.txt"))
  |> Stream.run

A file can be downloaded as follows - in this example a remote file "test2.csv" is downloaded to the local file "filename.txt"

SftpEx.stream!(connection,"test2.csv") |> Stream.into(File.stream!("filename.txt")) |> Stream.run

or using Enum.into

SftpEx.stream!(connection, "test2.csv") |> Enum.into(File.stream!("filename.txt"))

This follows the same pattern as Elixir IO streams so a file can be transferred from one server to another via SFTP as follows.

stream = 
  SftpEx.stream!(connection,"/home/path/filename.txt")
  |> Stream.into(SftpEx.stream!(connection2,"/home/path/filename.txt"))
  |> Stream.run

Upload a file

SftpEx.upload(connection, "remote_path", data)

Download a file

SftpEx.download(connection, "remote_path/carrot_recipes.txt")

Download a directory

SftpEx.download(connection, "remote_path/cat_vids")

List files in a directory

SftpEx.ls(connection, "remote_path/cat_vids")

Make a directory

SftpEx.mkdir(connection, "remote_path/cat_vids")

Get file info

SftpEx.lstat(connection, "remote_path/cat_vids/cat_on_trampoline.mp4")

## or

SftpEx.lstat(connection, handle)

Get file size

SftpEx.size(connection, "remote_path/cat_vids/cat_on_trampoline.mp4")

## or

SftpEx.size(connection, handle)

Get file type eg :regular or :directory

SftpEx.get_type(connection, "remote_path/cat_vids/cat_on_trampoline.mp4")

When you're done, disconnect

SftpEx.disconnect(connection)

Remove a file from the server

SSftpEx.rm(connection, "remote_path/cat_vids/cat_on_trampoline.mp4")

Remove a directory from the server

SSftpEx.rm_dir(connection, "remote_path/cat_vids/cat_on_trampoline.mp4")

Rename a directory or file on the server

SSftpEx.rm_dir(connection, "remote_path/cat_vids/cat_on_trampoline.mp4", "remote_path/cat_vids/old_cat_on_trampoline.mp4")

Append an existing file

SSftpEx.append(connection, "remote_path/cat_vids/cat_on_trampoline.mp4", more_data)

That's not all!

There is a lot of functionality exposed that isn't made available at the highest level that you can still utilize. Just dig into the code a bit and you'll see how.

Also as this is just a wrapper for :ssh_sftp you can still use anything in that lib and it will play nice with this one.