How to copy a file to a remote server in Python using SCP or SSH?

Question

I have a text file on my local machine that is generated by a daily Python script run in cron.

I would like to add a bit of code to have that file sent securely to my server over SSH.

Boutwell

Answer 1

You can call the scp bash command (it copies files over SSH) with subprocess.run:

import subprocess
subprocess.run(["scp", FILE, "USER@SERVER:PATH"])
#e.g. subprocess.run(["scp", "foo.bar", "[email protected]:/path/to/foo.bar"])

If you're creating the file that you want to send in the same Python program, you'll want to call subprocess.run command outside the with block you're using to open the file (or call .close() on the file first if you're not using a with block), so you know it's flushed to disk from Python.

You need to generate (on the source machine) and install (on the destination machine) an ssh key beforehand so that the scp automatically gets authenticated with your public ssh key (in other words, so your script doesn't ask for a password).

Cinnabar

@CharlesDuffy: subprocess.check_call(['scp', srcfile, dest]) could be used since Python 2.5 instead of rc = Popen(..).wait(); if rc != 0: raise .. – Petrify

adding ssh key is not a good solution when it is not needed. For example, if you need a one time communication, you don't set up ssh key due to security reasons. – Eipper

Answer 2

To do this in Python (i.e. not wrapping scp through subprocess.Popen or similar) with the Paramiko library, you would do something like this:

import os
import paramiko

ssh = paramiko.SSHClient() 
ssh.load_host_keys(os.path.expanduser(os.path.join("~", ".ssh", "known_hosts")))
ssh.connect(server, username=username, password=password)
sftp = ssh.open_sftp()
sftp.put(localpath, remotepath)
sftp.close()
ssh.close()

(You would probably want to deal with unknown hosts, errors, creating any directories necessary, and so on).

New

paramiko has a nice sftp.put(self, localpath, remotepath, callback=None) function too, so you don't have to open write, and close each file. – Cassandry

I would note that SFTP is not the same thing as SCP. – Psychodynamics

@Psychodynamics the question asks for the file to be sent over SSH. That's what this does. – New

Note: to make this work out of the box add ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy()) after instantiating ssh. – Zebapda

@Zebapda only if you don't want to use the known_hosts file – Stood

Any idea for an "scp" based solution? SFTP does not work with our server. – Taluk

Guys, is it safe to use the server password ? is there a possibility to use the Private Key ? – Vasyuta

It's certainly possible to use a private key: gist.github.com/batok/2352501 – Kesha

Interesting that this answer has almost three-fold more votes than accepted answer. – Rident

@Rident why? – Forenamed

@CanH.Tartanoglu I guess it's called individualism. I find something interesting that you do not. You can find something interesting that I do not. – Rident

@Rident I was just curious why you found it interesting. You don't have to defend yourself, everyone is entitled to an opinion. I just wanted to know because I didn't find it interesting. Cheers. – Forenamed

Answer 3

You'd probably use the subprocess module. Something like this:

import subprocess
p = subprocess.Popen(["scp", myfile, destination])
sts = os.waitpid(p.pid, 0)

Where destination is probably of the form user@remotehost:remotepath. Thanks to @Charles Duffy for pointing out the weakness in my original answer, which used a single string argument to specify the scp operation shell=True - that wouldn't handle whitespace in paths.

The module documentation has examples of error checking that you may want to perform in conjunction with this operation.

Ensure that you've set up proper credentials so that you can perform an unattended, passwordless scp between the machines. There is a stackoverflow question for this already.

Yucca

Using subprocess.Popen is the Right Thing. Passing it a string rather than an array (and using shell=True) is the Wrong Thing, as it means filenames with spaces don't work correctly. – Lanielanier

instead of "sts = os.waitpid(p.pid, 0)", we can use "sts = p.wait()". – Prompt

is there an execution free way of it with direct python API for this protocol? – Taluk

subprocess.check_call(['scp', myfile, destination]) could be used instead since Python 2.5 (2006) – Petrify

@J.F.Sebastian: yep, I checked it out in December. My upvotes prove that, at least. :) Thanks for the follow-up though. – Taluk

Answer 4

Reached the same problem, but instead of "hacking" or emulating command line:

Found this answer here.

from paramiko import SSHClient
from scp import SCPClient

ssh = SSHClient()
ssh.load_system_host_keys()
ssh.connect('example.com')

with SCPClient(ssh.get_transport()) as scp:
    scp.put('test.txt', 'test2.txt')
    scp.get('test2.txt')

Keep

Note - this relies on the scp package. As of Dec 2017, the latest update to that package was in 2015 and the version number is 0.1.x. Not sure I would want to add this dependency. – Myself

so, it´s 2018 now and in may they released version 0.11.0. So, it seems SCPClient is not dead after all? – Damicke

the scp module is regulary updated (last was in June 2021) and has 380 stars on github. this is a legit solution. – Xylo

Answer 5

There are a couple of different ways to approach the problem:

1. Wrap command-line programs
2. use a Python library that provides SSH capabilities (eg - Paramiko or Twisted Conch)

Each approach has its own quirks. You will need to setup SSH keys to enable password-less logins if you are wrapping system commands like "ssh", "scp" or "rsync." You can embed a password in a script using Paramiko or some other library, but you might find the lack of documentation frustrating, especially if you are not familiar with the basics of the SSH connection (eg - key exchanges, agents, etc). It probably goes without saying that SSH keys are almost always a better idea than passwords for this sort of stuff.

NOTE: its hard to beat rsync if you plan on transferring files via SSH, especially if the alternative is plain old scp.

I've used Paramiko with an eye towards replacing system calls but found myself drawn back to the wrapped commands due to their ease of use and immediate familiarity. You might be different. I gave Conch the once-over some time ago but it didn't appeal to me.

If opting for the system-call path, Python offers an array of options such as os.system or the commands/subprocess modules. I'd go with the subprocess module if using version 2.4+.

Pettifogger

curious: what's the story on rsync vs. scp? – Boutwell

Answer 6

You can do something like this, to handle the host key checking as well

import os
os.system("sshpass -p password scp -o StrictHostKeyChecking=no local_file_path username@hostname:remote_path")

Alinaaline

Answer 7

fabric could be used to upload files vis ssh:

#!/usr/bin/env python
from fabric.api import execute, put
from fabric.network import disconnect_all

if __name__=="__main__":
    import sys
    # specify hostname to connect to and the remote/local paths
    srcdir, remote_dirname, hostname = sys.argv[1:]
    try:
        s = execute(put, srcdir, remote_dirname, host=hostname)
        print(repr(s))
    finally:
        disconnect_all()

Petrify

Answer 8

A very simple approach is the following:

import os
os.system('sshpass -p "password" scp user@host:/path/to/file ./')

No python library are required (only os), and it works, however using this method relies on another ssh client to be installed. This could result in undesired behavior if ran on another system.

Calmas

Answer 9

Using the external resource paramiko;

    from paramiko import SSHClient
    from scp import SCPClient
    import os

    ssh = SSHClient() 
    ssh.load_host_keys(os.path.expanduser(os.path.join("~", ".ssh", "known_hosts")))
    ssh.connect(server, username='username', password='password')
    with SCPClient(ssh.get_transport()) as scp:
            scp.put('test.txt', 'test2.txt')

Attaway

Answer 10

You can use the vassal package, which is exactly designed for this.

All you need is to install vassal and do

from vassal.terminal import Terminal
shell = Terminal(["scp username@host:/home/foo.txt foo_local.txt"])
shell.run()

Also, it will save you authenticate credential and don't need to type them again and again.

Pauiie

Answer 11

I used sshfs to mount the remote directory via ssh, and shutil to copy the files:

$ mkdir ~/sshmount
$ sshfs user@remotehost:/path/to/remote/dst ~/sshmount

Then in python:

import shutil
shutil.copy('a.txt', '~/sshmount')

This method has the advantage that you can stream data over if you are generating data rather than caching locally and sending a single large file.

Juvenescence

Answer 12

Try this if you wan't to use SSL certificates:

import subprocess

try:
    # Set scp and ssh data.
    connUser = 'john'
    connHost = 'my.host.com'
    connPath = '/home/john/'
    connPrivateKey = '/home/user/myKey.pem'

    # Use scp to send file from local to host.
    scp = subprocess.Popen(['scp', '-i', connPrivateKey, 'myFile.txt', '{}@{}:{}'.format(connUser, connHost, connPath)])

except CalledProcessError:
    print('ERROR: Connection to host failed!')

Yasminyasmine

Answer 13

Calling scp command via subprocess doesn't allow to receive the progress report inside the script. pexpect could be used to extract that info:

import pipes
import re
import pexpect # $ pip install pexpect

def progress(locals):
    # extract percents
    print(int(re.search(br'(\d+)%$', locals['child'].after).group(1)))

command = "scp %s %s" % tuple(map(pipes.quote, [srcfile, destination]))
pexpect.run(command, events={r'\d+%': progress})

See python copy file in local network (linux -> linux)

Petrify

Answer 14

Kind of hacky, but the following should work :)

import os
filePath = "/foo/bar/baz.py"
serverPath = "/blah/boo/boom.py"
os.system("scp "+filePath+" [email protected]:"+serverPath)

Quilting