I am writing a shell script where i want to ssh to a server and get the cpu and memory details data of that displayed as a result. I’m using the help of top command here.
Script line:
ssh -q user#host -n “cd; top -n 1 | egrep ‘Cpu|Mem|Swap’”
But the result is
TERM environment variable is not set.
I had checked the same in the server by entering set | grep TERM and got result as TERM=xterm
Please someone help me on this. Many thanks.
Try using the top -b flag:
ssh -q user#host -n "cd; top -bn 1 | egrep 'Cpu|Mem|Swap'"
This tells top to run non-interactively, and is intended for this sort of use.
top need an environment. You have to add the parameter -t to get the result:
ssh -t user#host -n "top -n 1 | egrep 'Cpu|Mem|Swap'"
Got it..!! Need to make a small modification for the below script line.
ssh -t user#host -n "top -n 1 | egrep 'Cpu|Mem|Swap'"
Instead of -t we need to give -tt. It worked for me.
To execute command top after ssh’ing. It requires a tty to run. Using -tt it will enable a force pseudo-tty allocation.
Thanks stony for providing me a close enough answer!! :)
Related
I am trying to find a way to connect to a list of servers written in a simple textfile to run one command and write the output to a file...
The small problem is, I have to login with a password... but it would not a problem to paste the password into the script.
the full command would be:
ssh "server_from_list.txt uptime | awk -F, '{sub(".*up ",x,$1);print $1}' >> /home/kauk2/uptime.out
lets assume the password is: abcd1234
Any suggestions??? I am not fit in scripting, sorry...
Many thanks to you all in advance...
regards,
Joerg
Ideally you should set up password-less login, but failing that you can use sshpass. First, get a single command working by trying the following:
export SSHPASS=abcd1234
Then you can try:
sshpass -e ssh user#server1 'uname -a'
When you get that debugged and working, you can use GNU Parallel to run the command on all servers in a file called list.txt
user#server1
user#server2
user#server3
user#server4
The command will be:
parallel -k -a list.txt sshpass -e ssh {} 'uptime'
I am trying to run a nested ssh -t -t but it won't provide me the environment variables when working with cat and echo.
#!/bin/bash
pass="password\n"
bla="cat <(echo -e '$pass') - | sudo -S su -"
ssh -t -t -t -t jumpserver "ssh -t -t -t -t server \"$bla\" "
I get an output without any variables taken into consideration. (e.g. PS1 does not get shown but commands work fine) The problem is related to cat <(echo -e '$pass') - but this was the way to keep echo alive after providing the password for sudo.
How can i achieve this and get environment variables to get a proper output?
Thanks.
The -tt is enough. Using more -t does not add any more effect and just makes an impression that you have no idea what are you doing.
What is the point of cat <(echo -e) construction? Writing just echo would result in the same, isn't it?
Why to use sudo su? sudo already does all you need, isn't it?
So how can it look in some fashionable manner?
pass="password\n"
bla="echo '$pass' | sudo -Si"
ssh -tt jumpserver "ssh -tt server \"$bla\""
And does it work? Try to debug the commands with -vvv switches to the ssh. It will show you what is actually executed and passed to each other shell.
I'm not quite sure what the issue is. I'm on Kali Linux 2.0 right now, fresh install. The following worked on Ubuntu 14.04 but it's not working anymore (maybe I accidentally changed it?). It looks correct to me, but every time it runs it blocks.
backup_folder=$(ssh -i /home/dexter/.ssh/id_rsa $server 'ls -t '$dir' | head -1')
This is part of a larger script. $server and $dir are set. When I run the command alone, I get the correct output, but it doesn't end the connection.
I don't know if this may help to solve the question but your command doesn't handle dirs with space in the filename. Add double quotes inside the single quote section like this:
SERVER='remoteServer' && REMOTE_DIR='remoteDir' && backup_folder=$(ssh -i /home/dexter/.ssh/id_rsa "${SERVER}" 'ls -t "'${REMOTE_DIR}'" | head -n1'); echo "${backup_folder}"
If it doesn't help try to add increasing number of -v switch to ssh to debug eventually reaching:
SERVER='remoteServer' && REMOTE_DIR='remoteDir' && backup_folder=$(ssh -vvv -i /home/dexter/.ssh/id_rsa "${SERVER}" 'ls -t "'${REMOTE_DIR}'" | head -n1'); echo "${backup_folder}"
If the verbose output does not help may be an MTU problem (these kind of problems are not of binary type, acts strangely).
You can try lowering MTU (usually 1500) on your side to solve:
sudo ifconfig eth0 mtu 1048 up
eth0 is obviously an example interface, use your own.
This question already has answers here:
Pass commands as input to another command (su, ssh, sh, etc)
(3 answers)
Closed 6 years ago.
I have the following
#!/bin/bash
USER='scott'
PASS='tiger'
ssh -t $USER#server006.web.com "sudo su - http"
This Works, but I was trying to get it to run a script afterwards, and if I do, using -c or <
The script does a grep like this:
grep -i "Exception:" /opt/local/server/logs/exceptions.log | grep -e "|*-*-*:*:*,*|" | tail -1 | awk -F'|' '{print $2}' >> log.log
This also works fine on it's own, but I need to be http to do it.
I cannot SCP the output of the script back to server001 either, so I'm stuck here,
Any ideas would be relay appreciated.
Ben
Try
ssh -t $USER#server006.web.com 'sudo -u http grep -i "Exception:" /opt/local/server/logs/exceptions.log | grep -e "|*-*-*:*:*,*|" | tail -1 | awk -F"|" "{print $2}" >> log.log'
Sudo already runs the command as a different user to there's no need to su again.
Only reason to do sudo su is to have a fast way to start a new shell with another user.
You probably want sudo -u instead of sudo su -:
ssh -t $USER#server006.web.com sudo -u http script
Guess I'm late to the party.
My solution:
ssh -t $USER#server006.web.com "sudo cat /etc/shadow"
and replace cat /etc/shadow with your desired program.
I am using ssh from a program which sends commands to ssh and parses answers. However, each time I log in, I get the welcome banner like:
Linux mymachine 3.2.0-4-686-pae #1 SMP Debian 3.2.54-2 i686
The programs included with the Debian GNU/Linux system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.
...
I do not want this banner, because my parser would need to deal with it. Is it possible to login with ssh and not to get this banner at the beginning?
You should be able to silence this banner, and other diagnostic messages, by passing -q to SSH:
ssh -q user#remote_host
If you want to make -q permanent for all your SSH sessions, do:
echo "LogLevel QUIET" >> ~/.ssh/config
What works here seems to depend on the operating system, SSH version, and the server-side configuration of sshd.
For connecting to a stock Ubuntu 18 server ssh -q didn't work for me, and neither did ssh -o LogLevel=error that is suggested elsewhere.
What did work is the comment posted under the question about creating a .hushlogin file in the remote user's home directory:
$ ssh myuser#myhost
Welcome to Ubuntu 18.04.2 LTS (GNU/Linux 4.15.0-55-generic x86_64)
<snip>
Last login: Thu Aug 1 14:04:26 2019 from 1.2.3.4
myuser#myhost$ touch .hushlogin
myuser#myhost$ exit
Then:
$ ssh myuser#myhost echo 'Test'
Test
This will run command1 command2 and command3 on the remote_host.
ssh user#remote_host 'command1; command2; command3'
No banners are displayed.
Try ssh -q to supress the banner message
If you expect more than 1000 lines in the server answer then replace 1000 with a corresponding number or the server answer will be truncated.
# Demo script file creation \
DIVIDER="___"; echo "echo $DIVIDER; echo 100; echo 200; echo 300;" > "./test.sh"; \
# \
# Getting the answer without the banner \
ssh -q login#server.name < "./test.sh" | grep -A1000 -e "^$DIVIDER" | tail -n +2
Success
100
200
300
The same command without
| grep -A1000 -e "^$DIVIDER" | tail -n +2
gives
Welcome to Ubuntu 16.04.3 LTS (GNU/Linux...
[...]
Run 'do-release-upgrade' to upgrade to it.
___
100
200
300
You can replace "___" (three underscores) with any exotic sign(s) or even password (which can't be found in the beginnings of lines of the banner).
To avoid the replacing 1000 with a corresponding number (and possible truncation of big server answers) search something about "how to grep all lines after match" and modify my code.
For running commands remotely:
#!/bin/bash
SCRIPT='
#Your commands
'
sshpass -p<pass> ssh -o 'StrictHostKeyChecking no' -p <port> user#host "$SCRIPT"
I answer my own question with the solution based on Keith Reynolds answer. I am using:
ssh my_host bash
allowing bash interaction without banner and without prompt.