ssh sudo to a different user execute commands on remote Linux server - linux

We have a password less authentication between the server for root user, I am trying to run the alias on remote server as below
#ssh remoteserver runuser -l wasadmin wasstart
But it is not working. Any suggestions or any other method to achieve it

Based on your comments as you need to sudo to wasadmin in order to run wasadmin, you can try this:
ssh remoteserver 'echo /path/to/wasadmin wasstart | sudo su - wasadmin'

For add an alias in linux you must run
alias youcommandname=‘command’
Notice:
This will work until you close or exit from current shell . To fix this issue just add this to you .bash_profile and run source .bash_profile
Also your profile file name depending on which shell you using . bash , zsh ,...

Related

How to sudo run a local script over ssh

I try to sudo run a local script over ssh,
ssh $HOST < script.sh
and I tried
ssh -t $HOST "sudo -s && bash" < script.sh
Actually, I searched a lot in google, find some similar questions, however, I don't find a solution which can sudo run a local script.
Reading the error message of
$ ssh -t $HOST "sudo -s && bash" < script.sh
Pseudo-terminal will not be allocated because stdin is not a terminal.
makes it pretty clear what's going wrong here.
You can't use the ssh parameter -t (which sudo needs to ask for a password) whilst redirecting your script to bash's stdin of your remote session.
If it is acceptable for you, you could transfer the local script via scp to your remote machine and then execute the script without the need of I/O redirection:
scp script.sh $HOST:/tmp/ && ssh -t $HOST "sudo -s bash /tmp/script.sh"
Another way to fix your issue is to use sudo in non-interactive mode -n but for this you need to set NOPASSWD within the remote machine's sudoers file for the executing user. Then you can use
ssh $HOST "sudo -n -s bash" < script.sh
To make Edward Itrich's answer more scalable and geared towards frequent use, you can set up a system where you only run a one line script that can be quickly ported to any host, file or command in the following manner:
Create a script in your Scripts directory if you have one by changing the name you want the script to be (I use this format frequently to change 1 word for my script name and create the file, set permissions and open for editing):
newscript="runlocalscriptonremotehost.sh"
touch $newscript && chmod +x $newscript && nano $newscript
In nano fill out the script as follows placing the directory and name information of the script you want to run remotely in the variable lines of runlocalscriptonremotehost.sh(only need to edit lines 1-3):
HOSTtoCONTROL="sudoadmin#192.168.0.254"
PATHtoSCRIPT="/home/username/Scripts/"
SCRIPTname="scripttorunremotely.sh"
scp $PATHtoSCRIPT$SCRIPTname $HOSTtoCONTROL:/tmp/ && ssh -t $HOSTtoCONTROL "sudo -s bash /tmp/$SCRIPTname"
Then just run:
sh ./runlocalscriptonremotehost.sh
Keep runlocalscriptonremotehost.sh open in a tabbed text editor for quick updating, go ahead and create a bash alias for the script and you have yourself an app-ified version of this frequently used operation.
First of all divide your objective in 2 parts. 1) ssh to the host. 2) run the command you want as sudo. After you are certain that you can 1) access the host and 2) have sudo privileges then you can combine the two commands with &&. What x_cmd && y_cmd does is that the y_cmd gets executed after x_cmd has exited successfully.

cd to directory and su to particular user on remote server in script

I have some tasks to do on a remote Ubuntu CLI-only server in our offices every 2 weeks. I usually type the commands one by one, but I am trying to find a way (write a script maybe?) to decrease the time I spend in repeating those first steps.
Here is what I do:
ssh my_username#my_local_server
# asks for my_username password
cd /path/to/particular/folder
su particular_user_on_local_server
# asks for particular_user_on_local_server password
And then I can do my tasks (run some Ruby script on Rails applications, copy/remove files, restart services, etc.)
I am trying to find a way to do this in a one-step script/command:
"ssh connect then cd to directory then su to this user"
I tried to use the following:
ssh username#server 'cd /some/path/to/folder ; su other_user'
# => does not keep my connection open to the server, just execute my `cd`
# and then tells me `su: must be run from terminal`
ssh username#server 'cd /some/path/to/folder ; bash ; su other_user'
# => keeps my connection open to the server but doesn't switch to user
# and I don't see the usual `username:~/current/folder` prefix in the CLI
Is there a way to open a terminal (keep connection) on a remote server via ssh and change directory + switch to particular in a automated way? (to make things harder, I'm using Yakuake)
You can force allocation of a pseudo-terminal with -t, change to the desired directory and then replace the shell with one where you are the desired user:
ssh -t username#server 'cd /some/path/to/folder && exec bash -c "su other_user"'
sudo -H keeps the current working directory, so you could do:
ssh -t login_user#host.com 'cd /path/to/dir/; sudo -H -u other_user bash'
The -t parameter of ssh is needed otherwise the second sudo won't be able to ask you for your password.

Shell script to Sudo in Remote Machine and execute commands

#!/bin/csh
ssh -o StrictHostKeyChecking=no xyz123#remotemachine.com
sudo -su rootuser
ksh
. /mydir/setup_env.ksh
ls -ltr
Above is the list of task i need to do.
Login into remote machine without password prompt
Run Sudo to get access to Root
Change shell to ksh
execute a script (setup_env.ksh)
List files using ls -ltr
When i execute this script from , lets say localunixmachine.com...
It ask me for password
once i enter password , it will transfer to remote machine but wont execute remaining commands
If i exit from remote session, it will execute remaining command.
Can you please Guide me whats the best way to accomplish what i am trying here.
first you can copy your ssh public key which you can generate ssh-keygen to authorized_keys to the remote server root/.ssh/authorized_keys
and then the script will be
ssh root#remotemachine.com "/bin/ksh mydir/setup_env.ksh"
I think this should work for executing multiple commands remotely:
#!/bin/bash
ssh -o StrictHostKeyChecking=no xyz123#remotemachine.com <<EOF
sudo -su rootuser
ksh
. /mydir/setup_env.ksh
ls -ltr
EOF
As for login to the server without password, you need to setup ssh authentication with keys.

Executing db2 command through ssh

trying to ssh to another system then perform db2 commands however using 'su db2admin -c' does not seem to work, although it works for normal system commands ..
#!/bin/bash
sshpass -p 'passw0rd' ssh root#server.com "su db2admin -c 'db2text start'"
this is the output ..
rob#laptop:~/Desktop$ ./script.sh
bash: db2text: command not found
Any ideas?
The PATH is not getting updated to the normal root users PATH. Either specify the full path to db2text or add a dash (-) before the username to reload the environment variables
I'll hazard a guess and say that root doesn't have any of the db2 stuff in hi path.
And since you're using su db2admin rather than su - db2admin db2admin inherits
root's environment. Try with that extra - thrown in.
That all said: why on earth aren't you connecting w/ passwordless keys as db2admin?
Another solution that worked ..
#!/bin/bash
sshpass -p 'passw0rd' ssh root#server.com "su db2admin -c '~/sqllib/bin/db2text start'"
But problem is db2 path may change, better to use Eric's answer.

Running Remote Root Scripts on Fedora

I'd like to automate root scripting actions on my remote Fedora server via SSH without having to install the scripts on the server. To do this, I'm trying to use Bash's inline script notation. This works fine in Ubuntu, but I'm getting strange errors on Fedora.
e.g.
#!/bin/bash
ssh -t myuser#myserver <<EOI
su -
ls /root
exit
exit
EOI
This gives me the output:
standard in must be a tty
ls: cannot open directory /root: Permission denied
I've also tried:
#!/bin/bash
ssh -t myuser#myserver <<EOI
sudo ls /root
exit
EOI
but this gives me:
sudo: no tty present and no askpass program specified
If I manually ssh in and run these commands, they run fine since myuser is in the sudoers file. I've Googled these errors and have tried some fixes, but nothing's worked so far. How do I resolve this?
Looks like you're being prompted for the password but have no way to enter it. Here's a few things that should help.
Try an extra -t option: ssh -tt myuser#myserver <<EOI
Also this is a handy trick to log on as root without the root password being enabled: sudo su -
As a last resort you can setup your user to sudo without a password using visudo. You might see some comments like these to help you out:
# Uncomment to allow members of group sudo to not need a password
# (Note that later entries override this, so you might need to move
# it further down)
# %sudo ALL=NOPASSWD: ALL

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