SFTP key error in Python when run in docker container

Question

I made a python code that connects with a SFTP server and reads data. The python script worked well when I ran it on my machine.

For deployment purpose I needed a docker image. So I made one.

However when I run the docker container I get the following Error:

Dockerfile code:

FROM python:3
ADD sftp.py /
ADD config.properties /

RUN pip install pandas pysftp requests configparser

CMD ["python","./sftp.py"]

Python code for connecting to sftp:

cnopts = pysftp.CnOpts(knownhosts=None)
cnopts.hostkeys = None
with pysftp.Connection(host=hostname,username=username,password=password,cnopts=cnopts) as sftp:
    sftp.chdir("Optimove_Output")

I am unable to figure out why it is not working within a docker container. As this code works when run without a container.

if you already know your host then add this in your Dockerfile `mkdir -p /root/.ssh/ && \ touch /root/.ssh/known_hosts && \ ssh-keyscan yourhost.com > ~/.ssh/known_hosts` so you will not need to mount the host directory. — Adiii, Oct 11 '19 at 04:52

score 2 · Answer 1 · answered Oct 11 '19 at 04:17

2

that is because in your localhost you have the file ´known_hosts´, try to run your Container so:

docker run -v $HOME/.ssh/known_hosts:/root/.ssh/known_hosts sbtech2

answered Oct 11 '19 at 04:17

LinPy

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How to make it flexible to automatically add every host as a known_hosts irrespective of the machine. Like I want the code to be machine independent – Aman Khandelwal Oct 11 '19 at 04:21
Like I meant if some other SFTP is to be connected. How to add that host to known host? – Aman Khandelwal Oct 11 '19 at 04:30
I tried that. Didn't worked – Aman Khandelwal Oct 11 '19 at 04:35
that will work, you need to have `known_hosts` just to make the warning go away. – LinPy Oct 11 '19 at 05:37

SFTP key error in Python when run in docker container

1 Answers1