This might be a silly question. I wanted to copy thousands of files from a remote server to my local machine using scp. I ran the below command directly on the command line of the remote server (after logging in with ssh)
for file in $(ls <SOURCE_DIR>)
do scp $file <LOCAL_ID>#<LOCAL_IP_ADDRESS>:<TARGET_DIR>
done
But after running this I realized that <TARGET_DIR> is owned by root, so the for loop requests a password, and if I enter the password it throws a Permission denied error message. This is repeating over and over again every loop cycle. Is there any way to get out of the for loop without pressing Ctrl + C thousands (the number of files in <SOURCE_DIR>) of times? Both the server and local use Ubuntu 18.04.
Bash itself will not let you access remote host , but you can use SSH:
Step 1: On your local PC generate key to perform password-free authentication later
$ ssh-keygen
It will ask you to enter passphrase. If you want your bash script to be fully non-interactive, you can opt not to use any password.
Step 2: Copy you public key to the remote host and paste it in .ssh/authorized_keys
Step 3: Use scp to copy files:
$ scp -ir .ssh/sshfile username#host:/sourcedirectory targetdirectory
The above command will copy all the files and folders in the respective source directory in the server
I am writing a shell scripts that requires to run commands on multiple remote host based on condition it satisfies. how can i run the commands on the remote host using its key pair and assign the output of those commands to a variable on the primary host.
I tried using
sshpass -f keypair hostname 'command' | 'commands'
but this command executed on the host itself.
Use command substitution to assign the output of a command to a variable. You also need to run the ssh command and specify the remote username.
variable=$(sshpass -f keypair ssh username#hostname 'command')
1) Add host public keys (~/.ssh/id_rsa.pub)to remote user authenticated keys (~/.ssh/authorized_keys)
You will append the content of the public key to the authorized_keys
2) If you don't have this key you may generate it
ssh-keygen -t rsa
3) after that you can
ssh <REMOTE USER NAME>#RemoteHOST <command>
As example
ssh mebada#123.44.2.12 ls
4) If you have list of commands you may scp shell file and execute it from there ( without password too ) and it will override the remote
scp /path/to/shell.file user#host:/path/to/remote
ssh user#host chmod u+x /path/to/remote/shell.file
ssh user#host /path/to/remote/shell.file
I have to move file from one server to the other server for which i am using
scp user#sourceservername:sourcefilepath user#destservername:destdirectory
when i execute this script it asks for password of both the source and destination. Can this scp command be included in a shell script such that the password is picked dynamically ? alongwith file name and file path ?
You can solve it by generating private/public keys for both servers.
Use ssh-keygen and ssh-copy-id later to copy your public key to both servers.
Steps:
ssh-keygen
ssh-copy-id user#sourceservername
ssh-copy-id user#destservername
scp -3 user#sourceservername:sourcefilepath user#destservername:destdirectory
Notice the -3 option, this will transfer the file from sourceservername to your local server and then to destservername. This way you will have only single pair of private/public keys.
I have an sftp connection to a server in Unix.
Without password, I use the syntax to connect and execute command
sftp -b $user#$server_name
Can anyone suggest me how can I write a shell script to connect a remote server non interactively using a password
Try with this below option,
lftp -u $user,$pass sftp://$host << --EOF--
cd $directory
put $srcfile
quit
--EOF--
You could use ~/.ssh/config file.
#
# ~/.ssh/config
#
Host servername
Hostname 127.127.127.127
Port 22
User root
#EOF: config
Then simply connect with "ssh servername" and if you don't want to use password you can use SSH key. Here is good tutorial on how to do that > http://www.cyberciti.biz/tips/linux-multiple-ssh-key-based-authentication.html
If you just want to pass user/server from terminal, you can do this.
#!/bin/bash
sftp -b "$1"#"$2"
then use it like this './sftp.sh user server'
use SCP like this;
scp -P 22 user#server:/dir/file.tgz ~/Desktop/
use SFTP like this;
sftp user#server:/dir/file.tgz ~/Desktop/file.tgz
You can also try this;
sftp user#host <<EOF
get /dir/file.tgz
rm /dir/file.tgz
EOF
The best way to do this would be to create a key pair on the client, and add the key to the target user's ~/.ssh/authorized_keys.
To create a key pair, run ssh-keygen and when it asks for a password, just hit return to indicate "no password". Then either run ssh-copy-id $user#$server_name or manually create a ~/.ssh/authorized_keys on the server and copy the contents of the ~/.ssh/id_rsa.pub from the client into it (ssh-copy-id isn't available on all machines, so on some you'll have to do it manually).
Now you should be able to run ssh or scp without a password, as it should use your key instead. If it doesn't work, make sure that the permissions on your ~/.ssh/ directory and contents are correct on both machines; the directory should be 0700 (drwx------) and the files should be 600 (-rw-------). Also check that key authentication is enabled on both the client and the server.
I need to transfer a log file to a remote host using sftp from a Linux host. I have been provided credentials for the same from my operations group. However, since I don't have control over other host, I cannot generate and share RSA keys with the other host.
So is there a way to run the sftp command (with the username/password provided) from inside the Bash script through a cron job?
I found a similar Stack Overflow question, Specify password to sftp in a Bash script, but there was no satisfactory answer to my problem.
You have a few options other than using public key authentication:
Use keychain
Use sshpass (less secured but probably that meets your requirement)
Use expect (least secured and more coding needed)
If you decide to give sshpass a chance here is a working script snippet to do so:
export SSHPASS=your-password-here
sshpass -e sftp -oBatchMode=no -b - sftp-user#remote-host << !
cd incoming
put your-log-file.log
bye
!
Another way would be to use lftp:
lftp sftp://user:password#host -e "put local-file.name; bye"
The disadvantage of this method is that other users on the computer can read the password from tools like ps and that the password can become part of your shell history.
A more secure alternative which is available since LFTP 4.5.0 is setting the LFTP_PASSWORD environment variable and executing lftp with --env-password. Here's a full example:
export LFTP_PASSWORD="just_an_example"
lftp --env-password sftp://user#host -e "put local-file.name; bye"
# Destroy password after use
export LFTP_PASSWORD=""
LFTP also includes a cool mirroring feature (can include delete after confirmed transfer --Remove-source-files):
lftp -e 'mirror -R /local/log/path/ /remote/path/' --env-password -u user sftp.foo.com
EXPECT is a great program to use.
On Ubuntu install it with:
sudo apt-get install expect
On a CentOS Machine install it with:
yum install expect
Lets say you want to make a connection to a sftp server and then upload a local file from your local machine to the remote sftp server
#!/usr/bin/expect
spawn sftp username#hostname.com
expect "password:"
send "yourpasswordhere\n"
expect "sftp>"
send "cd logdirectory\n"
expect "sftp>"
send "put /var/log/file.log\n"
expect "sftp>"
send "exit\n"
interact
This opens a sftp connection with your password to the server.
Then it goes to the directory where you want to upload your file, in this case "logdirectory"
This uploads a log file from the local directory found at /var/log/ with the files name being file.log to the "logdirectory" on the remote server
You can use lftp interactively in a shell script so the password not saved in .bash_history or similar by doing the following:
vi test_script.sh
Add the following to your file:
#!/bin/sh
HOST=<yourhostname>
USER=<someusername>
PASSWD=<yourpasswd>
cd <base directory for your put file>
lftp<<END_SCRIPT
open sftp://$HOST
user $USER $PASSWD
put local-file.name
bye
END_SCRIPT
And write/quit the vi editor after you edit the host, user, pass, and directory for your put file typing :wq .Then make your script executable chmod +x test_script.sh and execute it ./test_script.sh.
I was recently asked to switch over from ftp to sftp, in order to secure the file transmission between servers. We are using Tectia SSH package, which has an option --password to pass the password on the command line.
example : sftp --password="password" "userid"#"servername"
Batch example :
(
echo "
ascii
cd pub
lcd dir_name
put filename
close
quit
"
) | sftp --password="password" "userid"#"servername"
I thought I should share this information, since I was looking at various websites, before running the help command (sftp -h), and was i surprised to see the password option.
You can override by enabling Password less authentication. But you should install keys (pub, priv) before going for that.
Execute the following commands at local server.
Local $> ssh-keygen -t rsa
Press ENTER for all options prompted. No values need to be typed.
Local $> cd .ssh
Local $> scp .ssh/id_rsa.pub user#targetmachine:
Prompts for pwd$> ENTERPASSWORD
Connect to remote server using the following command
Local $> ssh user#targetmachine
Prompts for pwd$> ENTERPASSWORD
Execute the following commands at remote server
Remote $> mkdir .ssh
Remote $> chmod 700 .ssh
Remote $> cat id_rsa.pub >> .ssh/authorized_keys
Remote $> chmod 600 .ssh/authorized_keys
Remote $> exit
Execute the following command at local server to test password-less authentication.
It should be connected without password.
$> ssh user#targetmachine
The easiest way I found to accomplish this, without installing any third-party library like Expect, SSHPASS...etc, is by using a combination of CURL, and SFTP. Those two are almost in every Linux machine.
This is the command you should execute, after changing the values.
curl -k "sftp://SERVER_IP:SERVER_PORT/FULL_PATH_OF_THE_FILE" --user "SERVER_USER:SERVER_PASSOWRD" -o "THE_NAME_OF_THE_FILE_AFTER_DOWNLOADING_IT"
Example:
curl -k "sftp://10.10.10.10:77/home/admin/test.txt" --user "admin:123456" -o "test.txt"
Explanation:
We are connecting to the server 10.10.10.10:77 using the username admin and password 123456, to move the file /home/admin/test.txt from that server to the server you are using currently to execute the above command.
Combine sshpass with a locked-down credentials file and, in practice, it's as secure as anything - if you've got root on the box to read the credentials file, all bets are off anyway.
Bash program to wait for sftp to ask for a password then send it along:
#!/bin/bash
expect -c "
spawn sftp username#your_host
expect \"Password\"
send \"your_password_here\r\"
interact "
You may need to install expect, change the wording of 'Password' to lowercase 'p' to match what your prompt receives. The problems here is that it exposes your password in plain text in the file as well as in the command history. Which nearly defeats the purpose of having a password in the first place.
You can use sshpass for it. Below are the steps
Install sshpass For Ubuntu - sudo apt-get install sshpass
Add the Remote IP to your known-host file if it is first time
For Ubuntu -> ssh user#IP -> enter 'yes'
give a combined command of scp and sshpass for it.
Below is a sample code for war coping to remote tomcat
sshpass -p '#Password_For_remote_machine' scp /home/ubuntu/latest_build/abc.war #user##RemoteIP:/var/lib/tomcat7/webapps
You can use a Python script with scp and os library to make a system call.
ssh-keygen -t rsa -b 2048 (local machine)
ssh-copy-id user#remote_server_address
create a Python script like:
import os
cmd = 'scp user#remote_server_address:remote_file_path local_file_path'
os.system(cmd)
create a rule in crontab to automate your script
done
A few people have mentioned sshpass but not many clear coding examples...
This is how we are doing it with bash scripts for rsync backups:
sshpass -p "${RSYNC_PASSWORD}" sftp "${RSYNC_USER}"#"${RSYNC_REMOTE_HOST}"
Keep in mind you will have to sudo apt install sshpass before this works properly.