how to use value that is calculated inside ssh - linux

I have linux script like below:
sshpass -p "pwd" ssh -tt user << 'EOF'
cd /directory
file=$(ls -1t | head -1)
exit
EOF
How to use the file parameter outside ssh. That is after EOF statement.

I think that you have to work with the output of the SSH command to capture it into a local variable.
This could be a viable solution (tried with obviously different parameters locally, OS Ubuntu 17.04):
CMD=`cat <<EOF
cd /directory
ls -1t | head -1
EOF`
FILE=`sshpass -p "pass" ssh -t user#host -o LogLevel=QUIET "$CMD"`
echo "$FILE"

Related

Error when stacking SSH command arguments within a bash script using other scripts as variables

I have a csv file called addresses.csv which looks like this,
node-1,xx.xxx.xx.xx,us-central-a
....
node-9,xxx.xx.xxx.xx,us-east1-a
I have a script below called 0run.sh,
#!/bin/bash
username='user'
persist="bash /home/${username}/Documents/scripts/disk/persistentDisk.sh"
first="bash /home/${username}/Documents/scripts/disk/firstAttach.sh"
while IFS=, read -r int ip <&3; do
if [ "$int" == "node-1" ]; then
--->ssh -i ~/.ssh/key -o StrictHostKeyChecking=no -l ${username} ${ip} "${persist}; ${first}"<---
else
ssh -i ~/.ssh/key -o StrictHostKeyChecking=no -l ${username} ${ip} "${first}"
fi
done 3<addresses.csv
The error occurs in the part of the code where I drew the arrows.
When it runs on node-1, instead of running ..persistentDisk.sh followed by ..firstAttach.sh, it only runs ..persistentDisk.sh and gives me the following error before it runs ..persistentDisk.
bash: /home/user/Documents/scripts/disk/firstAttach.sh: No such file or directory
The rest of the script runs completely fine. The only error occurs at this one part where it misses the 2nd script.
When I run the command like this it runs fine.
ssh -i ~/.ssh/key -o StrictHostKeyChecking=no -l ${username} ${ext} "${first}"
When I run it like this, it runs fine as well.
ssh -i ~/.ssh/key -o StrictHostKeyChecking=no -l user xxx.xx.xxx.xx "bash /home/${username}/Documents/scripts/disk/persistentDisk.sh; bash /home/${username}/Documents/scripts/disk/firstAttach.sh"
When I run the command like with a \ before the ; to escape it like this,
ssh -i ~/.ssh/key -o StrictHostKeyChecking=no -l ${username} ${ext} "${persist}\; ${first}"
I get the following error, and neither scripts run within the node-1 part of the code, but the rest of the code's else loops run fine.
bash: /home/user/Documents/scripts/disk/persistentDisk.sh;: No such file or directory
Why can't I stack the 2 commands within the if statement in the ssh using variables?
If I clearly understand: your real problem consist to leave STDIN free for interaction in target host!
About read and redirection
Try using:
#!/bin/bash
username='user'
persist="bash /home/${username}/Documents/scripts/disk/persistentDisk.sh"
first="bash /home/${username}/Documents/scripts/disk/firstAttach.sh"
while IFS=, read -r -u $list int ip foo; do
if [ "$int" == "node-1" ]; then
echo CMD... $ip, $persist
else
[ "$ip" ] && echo CMD... $ip, $first
fi
done {list}<addresses.csv
Tested, this èroduce:
CMD... xx.xxx.xx.xx, bash /home/user/Documents/scripts/disk/persistentDisk.sh
CMD... xxx.xx.xxx.xx, bash /home/user/Documents/scripts/disk/firstAttach.sh
-u flag to read, tell to use file descriptor ${list} instead of STDIN
foo is some useless variable used to prevent rest of line to be stored in $ip (xx.xxx.xx.xx,us-central-a in this case)
{list}</path/to/filename create a new variable by finding any free file descriptor.
About ssh (and redirection)
You could use:
#!/bin/bash
username='user'
persist="/home/${username}/Documents/scripts/disk/persistentDisk.sh"
first="/home/${username}/Documents/scripts/disk/firstAttach.sh"
while IFS=, read -r -u $list int ip foo; do
[ "$int" = "node-1" ] && cmd=persist || cmd=first
[ "$ip" ] && ssh -i ~/.ssh/key -t -o StrictHostKeyChecking=no \
-l ${username} ${ext} /bin/bash "${!cmd}"
done {list}<addresses.csv
By using this syntax, you will keep STDIN free for script running on target host.

Run ls command inside ssh

I have a script something like below
sshpass -p "pwd" ssh -tt user#host << EOF
cd /directory
file=$(ls -1t| head -1)
exit
EOF
cd /directory is changing the directory successfully inside shell. But ls gives the result which is outside the shell. The result of ls is same as when executed outside ssh. Please help in this.
The $(...) part is being evaluated by the outer shell. You can disable this by quoting 'EOF' so that $(...) is passed to the remote shell. It's akin to using single quotes instead of double quotes with regular strings.
sshpass -p "pwd" ssh -tt user#host << 'EOF'
cd /directory
file=$(ls -1t| head -1)
exit
EOF

shell script for remote connection to other system and execute bunch of command in it

I need a shell script that can take remote login in to a system and i can execute a bunch of commands in that system.
I made a script and actually it's working:
#!/bin/bash
USERNAME=KRUNAL
IP=10.61.162.241
ssh -l ${USERNAME} ${IP} "pwd "
ssh -l ${USERNAME} ${IP} "ls -la"
ssh -l ${USERNAME} ${IP} ./a.out
I have problem that if suppose i made script
ssh -l ${USERNAME} ${IP} "pwd " # this execute in remote system
ls -la # this execute in current system.
so every time i need ssh command to execute file on remote system.
Is there any way that i can run bunch of code in remote system with one time login.
You can send as much commands to ssh as you want, provided that you separate them with ; or linebreaks. So this should work:
ssh -l ${USERNAME} ${IP} "pwd; ls -la"
#Joao's suggestion works fine however its impractical when writing many lines.
If this is the case you can do
ssh -1 ${USERNAME} ${IP} bash << 'EOF'
cd /some/directory
./a.out
who am i
for i in `seq 1 10`
do
echo $i
done
EOF
Anything between 'EOF' and the final EOF will be executed in the server side.
You can also replace bash with csh or python and write code for that interpreter instead
If you want the output of the ssh session be stored in a file (say session.log) then replace
ssh -1 ${USERNAME} ${IP} bash << 'EOF'
with
ssh -1 ${USERNAME} ${IP} bash << 'EOF' > 'session.log'
rest remains unchanged

How to log non-interactive bash command sent through ssh

I'm sending a command through ssh:
ssh server.org 'bash -s' << EOF
ls -al
whoami
uptime
EOF
How to log it in the system (remote server)? I'd like to log those commands in some file (.bash_history or /tmp/log).
I've tried to add the line below to sshd_config:
ForceCommand if [[ -z $SSH_ORIGINAL_COMMAND ]]; then bash; else echo "$SSH_ORIGINAL_COMMAND" >> .bash_history; bash -c "$SSH_ORIGINAL_COMMAND"; fi
But it logs "bash -s" only.
I'll appreciate any help.
When bash shell exits, bash reads and executes commands from the ~/.bash_logout file. Probably you can run the history command at the end in the .bash_logout(of the server) and save it to some location.
If it suffices to work with the given command, we can put the necessary additions to enable and log command history at the beginning and end, e. g.
ssh server.org bash <<EOF
set -o history
ls -al
whoami
uptime
history|sed 's/ *[0-9]* *//' >>~/.bash_history
EOF
Or we could put them into the awfully long ForceCommand line:
… if [[ "$SSH_ORIGINAL_COMMAND" == bash* ]]; then echo "set -o history"; cat; echo "history|sed 's/ *[0-9]* *//' >>~/.bash_history"; else cat; fi | bash -c "$SSH_ORIGINAL_COMMAND"; fi

Bash script does not ssh all the entries of a csv file

I am trying to patch a bunch of CENT OS machines with the latest fix pack. I have the below bash script that takes csv file as a input which has the ip address and password for those machines.
The code works fine however, it would only work for the first row it does not seem to be working for the rest of the list as my output.txt only has the entry only for the first row host .
patch.sh
INPUT=hosts_test.cvs
OLDIFS=$IFS
IFS=,
[ ! -f $INPUT ] && { echo "$INPUT file not found"; exit 99; }
while read privateip password
do
sshpass -p$password ssh -t -o "StrictHostKeyChecking no" user123#$privateip "
hostname
hostname -I --all-ip-addresses
sudo yum -y update bash
env x='() { :;}; echo vulnerable' bash -c \"echo If you see the word vulnerable above, then you are vulnerable to shellshock\"
echo ""
exit
" >> output.txt
done < $INPUT
IFS=$OLDIFS
hosts_test.cvs
10.xxx.xx.219,abcd~qY1
10.xxx.xx.226,l4~abcdefg
10.xxx.xx.221,l4#abcdefgh
Terminal Output
Pseudo-terminal will not be allocated because stdin is not a terminal.
Add at the end of your sshpass command </dev/null.
Add Defaults:username !requiretty to your /etc/sudoers config
Get rid of -t from your ssh command
Optional, but recommended: set up public key auth so you don't have your passwords lying around in text files.
You can pass ssh another -t to force pty allocation:
ssh -t -t

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