Scp command over ssh without password in script

Question

Here is my problem: I would like to perform scp command after ssh to remote server without typing any passwords. I describe my steps. My first steps were:

ssh-keygen -t rsa and

local@host$ ssh-copy-id -i /root/.ssh/id_rsa.pub remote@host on local machine

Then I did the same on remote machine:

ssh-keygen -t rsa and

remote@host$ ssh-copy-id -i /root/.ssh/id_rsa.pub local@host

After all described above I could do ssh on both machines without typing any password. I could perform scp command on remote machine like scp /home/remote/info.txt.gz local@host:/root/ and everything worked perfectly.

Then I tried to make a script with some actions described below and the last step in my script was scp command that did not work as I expected.

#!/bin/bash
remote_user=$1
remote_host=$2
local_user=$3
local_host=$4

echo "Testing connection to ${host}..."
ssh -n -o NumberOfPasswordPrompts=0 ${remote_user}@${remote_host}
if [ $? -ne 0 ]; then
    echo "FATAL: You don't have passwordless ssh working."
    echo "Try running ssh-keygen"
    exit 1
fi
echo "Okey. Starting the process."
ssh ${remote_user}@${remote_host} netstat -tulpn > /home/${remote_user}/info.txt;uptime |awk '{ print $3 }' >> /home/${remote_user}/info.txt;
if [ $? -ne 0 ]; then
    echo "An error occurred."
else
    echo "File is ready for gzipping!"
fi
gzip /home/${remote_user}/info.txt
if [ $? -ne 0 ]; then
    echo "file was not archived"
else
    echo "Archive is ready!"
fi
echo "Starting copy archive from ${remote_host} to ${local_host}"
scp /home/${remote_user}/info.txt.gz ${local_user}@${local_host}:/root/
if [ $? -ne 0 ]; then
    echo "Error while transferring!"
else
    echo "Copy has been transferred successfully!"
fi

Scp command asked me for password o_O.

When I did all steps in script manually everything worked perfectly but in script scp demanded password. I read a lot through stackexchange and found this answer Using an already established SSH channel. This answer requires Open SSH but my problem can be resolved manually via SSH as I said but in script it did not work. What am I going to do to make scp works without password?

Answer 1

If below scp command is being run on local_host,then you are trying to scp as local_user to local_host as local_user - ofcourse this would prompt for password, as you had only password less login for remote <-> local users only - not local <-> local

scp /home/${remote_user}/info.txt.gz ${local_user}@${local_host}:/root/

Answer 2

If you have already setup ssh keys, then look into transffering files using sftp. Single command, you don't need to go by the way you are currently trying to do it i.e. ssh then scp, plain sftp would work.