I have a shell script which I need to execute from server A which executes commands in Server B as well. But I can execute those commands only being a root user in server B.
Manually if I login to server B then I have to change the user to root and execute delete commands. To automate this I am trying to write a script and execute from server A, but it asks me for password. How do I add my password in the script? (Though it is not recommended), or please suggest if any other way to tackle this.
Add your username in /etc/sudoers with nopasswd to remove password prompt
$ visudo
user ALL=(ALL) NOPASSWD: ALL
You can use sshpass command with -p option
sshpass -p 'your_password' ssh root#your_host ls
refer manual of sshpass for more options
Related
I'm writing script to test unix commands. one of them is the SCP command, where the certs are set up , so it did not ask for the password on normal scenario.
scp /tmp/test.txt $userid#$hostname:$path
But assume scenario like certs were deleted or the user id is wrong then the script is not getting completed as scp asks for password
On the terminal
scp /tmp/test.txt $userid#$hostname:$path
Password:
So how can i force not to prompt for password and just fail in case it can not validate.
The scp command was stored in a variable line and is executed as below
`$line`
Typically:
scp -o BatchMode=yes ..
Taken from the scp man pages:
-B Selects batch mode (prevents asking for passwords or
passphrases).
I am on a server and running a script file that has following code.
ssh username#servername
sudo su - root
cd /abc/xyz
mkdir asdfg
I am able to ssh... but then the next command is not working.. the script is not sudo-ing. any idea?
Edit: Able to create a mech id and then do the things.. though still looking for the answer to above question :|
First of all your command will "stuck" on the first line because it will go into an interactive mode. The ssh command will require a password to be provided by a user (unless there is an sshkey being used) . And if the ssh is logged into the remote server then it will wait for user commands from standard input.
Secondly the lines following the ssh command will be executed only when the first process has exited. This is why your script is not "sudoing" - it's waiting for the ssh to end.
So if your point is to run a command on a remote server then put the command as a parameter into the same line as ssh connection. In your case:
ssh user#server sudo su - root
But this will not be of satisfaction for you. I suggest you create a script of what you want to execute on the remote server and then execute the script.
ssh user#server scriptName
The sudo thing here is very tricky because again your script might get stuck in the interactive mode waiting for a password to be inserted so I suggest you think again on the basis of the script.
mb47!
You want to run the script on the remote computer, correct?
On the remote machine, create a file containing the commands you would like to execute.
Then, on the other machine, run ssh user#machine /path/to/script/you/created/earlier
I hope this helps!
ALinuxLover
I am trying to login to Server B from Server A and perform simple UNIX commands on Server B using a shell script. The code is as follows. But ls -al is displaying the result of Server A and not the one that is logged on to i.e Server B. Any inputs are highly appreciated. Thanks
#!/bin/bash
clear
sshpass -p password ssh hostname
ls -al
exit
When the shell interprets a script file, it creates a child process to
execute each command line. So, the command lines after sshpass -p password ssh hostname are not actually executed inside the ssh
session to hostname, but in the host where the bash instance is
running.
To achieve what you want, you can check ssh(1) usage line and note that there is a [command] argument, that says:
If command is specified, it is executed on the remote host instead
of a login shell.
So, one way to do it is sshpass -p password ssh hostname ls -la. Another way which can provide some more flexibility is:
#!/bin/bash
clear
cat | sshpass -p password ssh hostname <<EOF
ls -la
EOF
Which would make ssh start a login shell in the remote host and pass
to its stdin the lines provided in the Here Document. The remote
shell would then interpret those strings as commands and execute them.
If you just want to run ls -al on the remote server, put it on the same line as the ssh command like
sshpass -p password ssh hostname ls -al
it will automatically exit when it gets to the end of the command so you don't need to put exit
Also, if you're going to be doing this and don't want to interactively enter the password, you might want to look at sharing public/private keys and using that so it won't ever ask for a password (unless you password protect your private key)
I am using below command to open putty through windows command prompt:
PUTTY.EXE -ssh -pw "mypass" user#IP -m C:/my.sh -t
Where my.sh mentioned in above command file contains:
sudo su - rootuser
After executing the command, putty console is opened and it prompts for password.
Is there any way where I can provide this password automatically without typing it?
There's a bit of a horrible workaround using Expect and embedding a password.
This is a bad idea.
As an alternative:
Configure sudo to allow NOPASSWD.
Login directly as root using public-private key auth.
Both these introduce a degree of vulnerability, so should be used with caution - but any passwordless auth has this flaw.
Finally, after struggling for almost whole day, I got the way to get this working.
Below command can be executed from windows machine:
PLINK.EXE -t -ssh -pw "password" user#IP /home/mydir/master.sh
master.sh file is located on remote machine. And this file contains below command to execute script with sudo command without prompting password.
echo password | sudo u user -S script.sh
Here, password should be replaced with your password. user should be replaced with your actual user and script.sh is the script on remote machine that you want to fire after sudo login.
Assume I am user A(not root user) and I want to run a c-shell script which will execute command in User B(password for B is known to me) and will use the result of that command here.
How can I run a command in User-B.
sudo -u username command1
Above command may prompt for password but I want this to be done in script only.
Thanks for all your suggestions.
you could use a ssh key to allow your user A to log in as user B using user A's private key (and with user A's public key in ~B/.ssh/authorised_keys)
then you simply execute the script as B with:
ssh B#localhost "/path/to/script and maybe some arguments here"
you have following options,
run your command with root so that su - username wont prompt for password
create passordless login for user like passwordless ssh,remove password for user etc. and then run your command
for getting output here to work,
write it in a file and access it in code
store it in a variable and access it in code