I am trying to execute commands over ssh remotely.
It's 2x remote (2 level deep).
From my host, I ssh into target1 which is connected to target2.
I need the commands executed on target2.
There is no direct connection from host to target2.
Ex:
ssh root#target1 -t "ssh root#target2 -t "cat /usr/value""
The above command works.
ssh root#target1 -t "ssh root#target2 -t "echo 1 > /usr/value""
This command does not work. I get "No such file or directory"
You are trying to use a shell feature (redirection) instead of a command, so run that via shell (note: quoting gets tricky):
ssh -t root#target1 'ssh -t root#target2 /bin/bash -c \"echo 1 > /usr/value\"'
I suggest you study the man page for ssh_config. For instance, with this:
Host target2
User root
ProxyJump root#target1
your above command would be:
ssh -t target2 '/bin/bash -c "echo 1 > /usr/value"'
The next step is to use ansible (or similar) for system changes.
Related
I have gitlab CI job which had a script execution like below:
stage: permissions
script:
sshpass -p "${PASSWORD}" ssh ${USER}#${HOST} sudo chown -cv user_a:user_a ${directory}/test.txt
The above gives me following error:
sudo: sorry, you must have a tty to run sudo
If i add -t with ssh i get:
Pseudo-terminal will not be allocated because stdin is not a terminal.
sudo: sorry, you must have a tty to run sudo
If i add -tt with ssh, the job keeps waiting for me to enter the password.
My requirement is to execute a remote command using ssh and text password i.e. sshpass, is there a way i can achieve this without change any sudoers permissions over the server?
Use somethinc like:
sshpass -p "${PASSWORD}" ssh ${USER}#${HOST} sh -c "echo ${PASSWORD} | sudo chown -cv user_a:user_a ${directory}/test.txt"
Example for write password from not tty to sudo:
echo ${PASSWORD} | sudo -S command
p.s. For configure servers use Ansible, he handles such tasks very easily.
Commands the server through ssh.
The output of each command must be stored separately.
ssh -i ~/c.pem ubuntu#server 'cd /tmp'
ssh -i ~/c.pem ubuntu#server 'pwd'
I want to have "/tmp" output when I run this code.
How do I run multiple commands in previous session?
Use a ; between commands to execute them sequentially.
ssh -i ~/c.pem ubuntu#server 'cd /tmp; pwd'
ssh -t remotehost vim /tmp/x.txt
I know that I can run a command like the above.
But I would like to be able to run any local bash code in a remote machine. For this reason, I'd like to call the remote 'bash -s' so that can process any local bash code.
ssh -t remotehost 'bash -s' <<< vim /tmp/x.txt
However, the above example shows "Pseudo-terminal will not be allocated because stdin is not a terminal." Is there any way to let ssh take local bash code via stdin and run it via the remote 'bash -s'? Thanks.
ssh -t remotehost 'bash -s' <<< vim /tmp/x.txt
You're getting the "Pseudo-terminal will not be allocated..." message because you're running ssh with a single -t option, when the standard input to the ssh process isn't a TTY. ssh prints that message specifically in this case. The documentation for -t says:
-t
Force pseudo-terminal allocation. This can be used to execute arbitrary screen-based programs on a remote machine, which can be very useful, e.g. when implementing menu services. Multiple -t options force tty allocation, even if ssh has no local tty.
The -t command-line option is related to the ssh configuration option RequestTTY:
RequestTTY
Specifies whether to request a pseudo-tty for the session. The argument may be one of: no (never request a TTY), yes (always request a TTY when standard input is a TTY), force (always request a TTY) or auto (request a TTY when opening a login session). This option mirrors the -t and -T flags for ssh(1).
A single -t is equivalent to "RequestTTY yes", while two of them is equivalent to "RequestTTY force".
If you want your remote command(s) to run with a TTY, then specify -t twice:
ssh -tt remotehost 'bash -s' <<< vim /tmp/x.txt
or
ssh -t -t remotehost 'bash -s' <<< vim /tmp/x.txt
ssh will allocate a TTY for the remote system and it won't print that message.
If the command(s) being run on the remote system don't require a TTY, you can leave the -t option out:
ssh remotehost 'bash -s' <<< vim /tmp/x.txt
I believe the following might suit your purposes:
vim /tmp/x.txt ; ssh remotehost 'bash -s' < /tmp/x.txt
The first expression (vim ...) allows you to specify the commands you want to execute remotely as a local file called /tmp/x.txt; the second expression (ssh ...) calls the remote bash interpreter, and sends the contents of your local file to it for execution. Note that you do not need the -t option for ssh in this case (which gave rise to the pseudo-terminal warning), and that you do not need to use a here string (<<<) but can use the normal file input operator (<).
This solution seems to work for, e.g., the following file contents:
echo These commands are being executed on $HOSTNAME
echo This is a second command
I am looking to script something in batch which will need to run remote ssh commands on Linux. I would want the output returned so I can either display it on the screen or log it.
I tried putty.exe -ssh user#host -pw password -m command_run but it doesn't return anything on my screen.
Anyone done this before?
The -m switch of PuTTY takes a path to a script file as an argument, not a command.
Reference: https://the.earth.li/~sgtatham/putty/latest/htmldoc/Chapter3.html#using-cmdline-m
So you have to save your command (command_run) to a plain text file (e.g. c:\path\command.txt) and pass that to PuTTY:
putty.exe -ssh user#host -pw password -m c:\path\command.txt
Though note that you should use Plink (a command-line connection tool from PuTTY suite). It's a console application, so you can redirect its output to a file (what you cannot do with PuTTY).
A command-line syntax is identical, an output redirection added:
plink.exe -ssh user#host -pw password -m c:\path\command.txt > output.txt
See Using the command-line connection tool Plink.
And with Plink, you can actually provide the command directly on its command-line:
plink.exe -ssh user#host -pw password command > output.txt
Similar questions:
Automating running command on Linux from Windows using PuTTY
Executing command in Plink from a batch file
You can also use Bash on Ubuntu on Windows directly. E.g.,
bash -c "ssh -t user#computer 'cd /; sudo my-command'"
Per Martin Prikryl's comment below:
The -t enables terminal emulation. Whether you need the terminal emulation for sudo depends on configuration (and by default you do no need it, while many distributions override the default). On the contrary, many other commands need terminal emulation.
As an alternative option you could install OpenSSH http://www.mls-software.com/opensshd.html and then simply ssh user#host -pw password -m command_run
Edit: After a response from user2687375 when installing, select client only. Once this is done you should be able to initiate SSH from command.
Then you can create an ssh batch script such as
ECHO OFF
CLS
:MENU
ECHO.
ECHO ........................
ECHO SSH servers
ECHO ........................
ECHO.
ECHO 1 - Web Server 1
ECHO 2 - Web Server 2
ECHO E - EXIT
ECHO.
SET /P M=Type 1 - 2 then press ENTER:
IF %M%==1 GOTO WEB1
IF %M%==2 GOTO WEB2
IF %M%==E GOTO EOF
REM ------------------------------
REM SSH Server details
REM ------------------------------
:WEB1
CLS
call ssh user#xxx.xxx.xxx.xxx
cmd /k
:WEB2
CLS
call ssh user#xxx.xxx.xxx.xxx
cmd /k
In ssh, I can use ssh root#myhost -t "cd mydir; bash -i" to do that, how can I run 2 commands in mosh with one line
According to man mosh(1), you can do the same with mosh, but you need to add the -t option to the ssh:
mossh root#myhost --ssh="ssh -t" "cd mydir; bash -i"