SCP via Python Subprocess Popen: "Identity File not accessible"

Question

When executing SCP from subprocess.popen I recieve the error: Warning: Identity File ./id_rsa.key not accessible: no such file or directory. The problem is explained below.

I want to SCP a file from a local machine to a remote machine, using a python script, and I want to specify the key to use when executing SCP (using -i option).

My local machine is Windows 10 Enterprise. My 'remote' machine is currently a Docker container running Alpine linux on my localhost.

When I run the command in an elevated shell, it works:

scp -i ./id_rsa.key -P 2222 ./test.plan [email protected]:/go/

When I execute the command via Python 3.6 subprocess.popen:

SSH = subprocess.Popen(['scp', '-i ./id_rsa.key', '-P 2222', './test.plan', '[email protected]:/go/'],
    cwd = r'C:\ThePathToThisStuff',
    shell = False,
    stdout=subprocess.PIPE,
    stderr=subprocess.PIPE
)

It prompts me for a password, [email protected]'s password:, and when I enter the password it throws the error below, indicating that it fails to find the RSA key:

<_io.TextIOWrapper name='<stderr>' mode='w' encoding='utf-8'> ERROR: [b'Warning: Identity file  ./id_rsa.key not accessible: No such file or directory.\n']

I've tried providing absolute paths to the keys, seperating each command in the arguments list into options and values, different groupings, etc.

Answer 1

You should not combine an option and its argument in the same parameter, they need to be separate list elements.

SSH = subprocess.Popen(['scp', '-i', './id_rsa.key', '-P', '2222', './test.plan', '[email protected]:/go/'],