Execute command in variable with bash through ssh - bash

I face an issue while sending a command to a local variables in ssh. Actually my variable doesn't receive the expected execution of the coding instructions.
If someone has an idea about the good syntax to be applied...
ssh -T $HR_HST -l $HR_USR -q -o StrictHostKeyChecking=no <<END_SSH_0
HermesShowCmd="sfe in;fname=$INPUT_WPPComOutFile;node=$Node;format=1" #ok
$HermesFolder/hcl \$HermesShowCmd >> $HR_LOG/$HRM_LOG #ok
HermesStatus=`$HermesFolder/hcl "$HermesShowCmd" | grep "Taken: \.\.\." | wc -l` #KO... variable not updated...
echo "$(date) --HermesStatus=\$HermesStatus" >> $HR_LOG/$HRM_LOG
END_SSH_0

Related

grep command inside EOF doesn't seems to be executing on remote hosts [UNIX BASH]

Here is the chunk of code for reference:-
Output:
I have checked the variable values using echo and those looks fine.
But what I want do achieve is searching logs on remote hosts using grep which does not give any output.
for dir in ${log_path}
do
for host in ${Host}
do
if [[ "${userinputserverhost}" == "${host}" ]]
then
ssh -q -T username#userinputserverhost "bash -s" <<-'EOF' 2>&1 | tee -a ${LogFile}
echo -e "Fetching details: \n"
`\$(grep -A 5 -s "\${ID}" "\${dir}"/archive/*.log)`
EOF
fi
break
done
done
First, remove all the crap around the grep.
Second, you're overquoting your vars.
Third, skip the "bash -s" if you can.
ssh -q -T username#userinputserverhost <<-'EOF' 2>&1 | tee -a ${LogFile}
echo -e "Fetching details: \n"
grep -A 5 -s "${ID}" "${dir}"/archive/*.log
EOF
Fourth, I don't see where $ID is set...so if that's being loaded on the remote system by the login or something, then that one would need the dollar sign backslashed.
Finally, be aware that here-docs are great, but sometimes here-strings are simpler if you can spare the quotes.
$: ssh 2>&1 dudeling#sandbox-server '
> date
> whoami
> ' | tee -a foo.txt
Fri Apr 30 09:23:09 EDT 2021
dudeling
$: cat foo.txt
Fri Apr 30 09:23:09 EDT 2021
dudeling
That one is more a matter of taste. Even better, if you can, write your remote-script to a local file & use that. And of course, you can always add set -vx into the script to see what gets remotely executed.
cat >tmpScript <<-'EOF'
echo -e "Fetching details: \n"
set -vx
grep -A 5 -s "${ID}" "${dir}"/archive/*.log
EOF
ssh <tmpScript 2>&1 -q -T username#userinputserverhost | tee -a ${LogFile}
Now you have an exact copy of what was issued for debugging.
Thanks Paul for spending time and coming up with suggestions/solutions.
I have managed to get it working couple of days back. Would have felt happy to say that your solution worked 100% but even satisfied that I got it sorted on my own as it helped me learn some new stuff.
FYI - grep -A 5 -s "${ID}" "${dir}"/archive/*.log - this will work but only by using shell built-in 'declare -p' to declare the variables within EOF. Also, I read somewhere and it is recommended to use EOF unqouted as it caters variable expansion to remote hosts without any trouble.
Below piece of code is working for me in bash:
ssh -q -T username#userinputserverhost <<-EOF 2>&1 | tee -a ${LogFile}
echo -e "Fetching details: \n"
$(declare -p ID)
$(declare -p dir)
grep -A 5 -s "${ID}" "${dir}"/archive/*.log
EOF

How to run for loop inside heredoc while accessing remote machine

Here is my script in which I use local variable inside a remote machine using heredoc. But the loop under the heredoc takes the first variable value only. The loop runs fine inside the heredoc but with the same values.
#!/bin/bash
prod_web=($(cat /tmp/webip.txt));
new_prod_app_private_ip=($(cat /tmp/ip.txt));
no_n=($(cat /tmp/serial.txt));
ssh -t -o StrictHostKeyChecking=no ubuntu#${prod_web[0]} -p 2345 -v << EOF
set -xv
for (( x = 0; x < '${#no_n[#]}'; x++ ))
do
sudo su
echo '${no_n[x]}'
echo '${new_prod_app_private_ip[x]}'
curl -fIkSs https://'${new_prod_app_private_ip[x]}':9002 | head -n 1
done
EOF
So, my ip.txt file contains values like:
10.0.1.0
10.0.2.0
10.0.3.0
My serial.txt file:
9
10
11
So, my loop runs for only the first IP (present in /tmp/ip.txt) in the remote machine, three times. I want to run it for all the three IPs. My remote ip is present in the file /tmp/webip.txt.
Got stuck for a long time, any help is appreciated. Is there any other solution that I can go with?
There are 2 environments. On your local machine and on the remote machine. You need to think how to transfer data/variables/state/objects/handles between these machines.
If you set something on your local machine (ie. prod_web=($(cat /tmp/webip.txt));) and then just ssh to remote host (ie. ssh user#host 'echo "${prod_web[#]}"'), the variable will not be visible/exported to the remote machine. You can:
scp the files {ip,serial}.txt and execute the whole script on the remote machine, then cleanup , ie. remove the {ip,serial}.txt files from the remote machine
pass the files {ip,serial}.txt somehow merged/joined/pasted to the stdin of the ssh and then read up stdin on the remove machine
create all the commands to run on your local machine and then pass pre-prepared commands to remote machine, like ssh .... "$(for ...; do; echo curl ...; done)"
I would go with the second option, as I like passing everything using pipes and don't like to cleanup after me - removing temporary files in case of error can be a mess.
My script would probably look like this:
#!/bin/bash
set -euo pipefail
read -r host _ <webip.txt
paste serial.txt ip.txt | ssh -t -o StrictHostKeyChecking=no -p 2345 -v ubuntu#"$host" '#!/bin/bash
set -euo pipefail
while read -r no_n ip; do
for ((i = 0; i < no_n; ++i)); do
printf "%s\n" "$no_n"
printf "%s\n" "$ip"
curl -fIkSs https://"$ip":9002 | head -n 1
done
done
'
As the remote script would become larger and less qouting friendly, I would save it into another remote_scripts.sh and execute ssh ... -m remote_scripts.sh.
I don't get what you are trying to do with that sudo su, which 100% does not do what you want.
If the no_n magic number is the number of times to execute that curl and you have xargs and you don't really care about errors, you can just do a magic and confusing oneliner:
#!/bin/bash
set -euo pipefail
read -r host _ <webip.txt
paste serial.txt ip.txt | ssh -t -o StrictHostKeyChecking=no -p 2345 -v ubuntu#"$host" 'xargs -n2 -- sh -c "seq 0 \"\$1\" | xargs -n1 -- sh -c \"curl -fIkSs https://\\\"\\\$1\\\":9002 | head -n 1\" -- \"\$2\"" --'
Preparing all the command to run maybe actually more readable and may save some nasty qouting to resolve. But this really depends on how big serial.txt and ip.txt are and how big are the commands to be executed on the remote machine, as you want to minimize the number of bytes transferred between machines.
Here the commands to run are constructed on local machine (ie. "$(...)" is passed to ssh) and executed on remote machine:
# semi-readable script, not as fast and no xargs
ssh -t -o StrictHostKeyChecking=no -p 2345 -v ubuntu#"$host" "$(paste serial.txt ip.txt | while read -r serial ip; do
seq 0 "$serial" | while read -r _; do
echo "curl -fIkSs \"https://$ip:9002\" | head -n 1"
done
done)"
HERE-doc does not expand shell commands, so:
$ cat <<EOF
> echo 1
> EOF
echo 1
but you can use command substitution $( ... ):
$ cat <<EOF
> $(echo 1)
> EOF
1

SSH in a script - commands not running on remote server [duplicate]

This question already has answers here:
Execute a command on remote hosts via ssh from inside a bash script
(4 answers)
Closed 7 years ago.
I need a help with a bash script that connect to server as root, execute some commands and then exit from the server.
I tried this script but when login login to server performed the command not running !
#!/bin/bash
sudo ssh -o ConnectTimeout=10 $1 'exit'
if [ $? != 0 ]; then
echo "Could not connect to $1 , script stopped"
exit
fi
sudo ssh $1
echo "SRV=`cat /etc/puppet/puppet.conf | grep -i srv_domain | awk '{print $3}'`"
echo $SRV
echo "puppetMaster=`host -t srv _x-puppet._tcp.$SRV | head -1 | awk '{print $8}' | cut -f1 -d"."`"
echo $puppetMaster
'exit'
I'm surprised nobody has suggested a heredoc yet.
sudo ssh "$1" <<'EOF'
SRV=`cat /etc/puppet/puppet.conf | grep -i srv_domain | awk '{print $3}'`
echo $SRV
echo "puppetMaster=`host -t srv _x-puppet._tcp.$SRV | head -1 | awk '{print $8}' | cut -f1 -d"."`"
echo $puppetMaster
EOF
This feeds everything from the <<'EOF' until the line starting with EOF into the stdin of ssh, to be received and run by the remote shell.
The commands following ssh machine in a script are not run on the machine. They will be run on the local machine once the ssh exits.
Either specify the commands to run as an argument of ssh, or alternatively, run ssh and make it read the commands from standard input, and send the commands to it.
ssh machine ls
# or
echo ls | ssh machine
You seem to be a little confused as to what runs where.
ssh -o ConnectTimeout=10 $1 'exit'
will connect to $1, run exit, and disconnect.
ssh -o ConnectTimeout=10 $1 'echo hello world'
will print hello world on
the server and then disconnect.
ssh $1
will open up a shell on the remote. After the shell has ended, the following commands will run locally.
echo "SRV=`cat /etc/puppet/puppet.conf | grep -i srv_domain | awk '{print $3}'`"
echo $SRV
echo "puppetMaster=`host -t srv _x-puppet._tcp.$SRV | head -1 | awk '{print $8}' | cut -f1 -d"."`"
echo $puppetMaster
'exit'
What you probably want is start bash on the remote and forward to it the commands you want to give it via stdin.
echo "my commands" | ssh $1 bash
Technically, you don't need that bash -- ssh will start bash even without it (but with different rc files).

Passing Bash Command Through SSH - Executing Variable Capture

I am passing the following command straight through SSH:
ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i /key/path server#111.111.111.111 'bash -s' << EOF
FPM_EXISTS=`ps aux | grep php-fpm`
if [ ! -z "$FPM_EXISTS" ]
then
echo "" | sudo -S service php5-fpm reload
fi
EOF
I get the following error:
[2015-02-25 22:45:23] local.INFO: bash: line 1: syntax error near unexpected token `('
bash: line 1: ` FPM_EXISTS=root 2378 0.0 0.9 342792 18692 ? Ss 17:41 0:04 php-fpm: master process (/etc/php5/fpm/php-fpm.conf)
It's like it is trying to execute the output of ps aux | grep php-fpm instead of just capturing git the variable. So, if I change the command to try to capture ls, it acts like it tries to execute that as well, of course returning "command not found" for each directory.
If I just paste the contents of the Bash script into a file and run it it works fine; however, I can't seem to figure out how to pass it through SSH.
Any ideas?
You need to wrap starting EOF in single quotes. Otherwise ps aux | grep php-fpm would get interpreted by the local shell.
The command should look like this:
ssh ... server#111.111.111.111 'bash -s' << 'EOF'
FPM_EXISTS=$(ps aux | grep php-fpm)
if [ ! -z "$FPM_EXISTS" ]
then
echo "" | sudo -S service php5-fpm reload
fi
EOF
Check this: http://tldp.org/LDP/abs/html/here-docs.html (Section 19.7)
Btw, I would encourage you to use $() instead of backticks consequently for command substitution because of the ability to nest them. You will have more fun, believe me. Check this for example: What is the benefit of using $() instead of backticks in shell scripts?
You should wrap the EOF in single quotes.
ssh -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -i /key/path server#111.111.111.111 'bash -s' << 'EOF'
FPM_EXISTS=`ps aux | grep php-fpm`
if [ ! -z "$FPM_EXISTS" ]
then
echo "" | sudo -S service php5-fpm reload
fi
EOF

Trying to use a wildcard with a variable in SSH comand [duplicate]

There are a number of files that I have to check if they exist in a directory. They follow a standard naming convention aside from the file extension so I want to use a wild card e.g:
YYYYMM=201403
FILE_LIST=`cat config.txt`
for file in $FILE_LIST
do
FILE=`echo $file | cut -f1 -d"~"`
SEARCH_NAME=$FILE$YYYYMM
ANSWER=`ssh -q userID#servername 'ls /home/to/some/directory/$SEARCH_NAME* | wc -l'`
returnStatus=$?
if [ $ANSWER=1 ]; then
echo "FILE FOUND"
else
echo "FILE NOT FOUND"
fi
done
The wildcard is not working, any ideas for how to make it visible to the shell?
I had much the same question just now. In despair, I just gave up and used pipes with grep and xargs to get wildcard-like functionality.
Was (none of these worked - and tried others):
ssh -t r#host "rm /path/to/folder/alpha*"
ssh -t r#host "rm \"/path/to/folder/alpha*\" "
ssh -t r#host "rm \"/path/to/folder/alpha\*\" "
Is:
ssh -t r#host "cd /path/to/folder/ && ls | grep alpha | xargs rm"
Note: I did much of my troubleshooting with ls instead of rm, just in case I surprised myself.
It's way better to use STDIN:
echo "rm /path/to/foldef/alpha*" | ssh r#host sh
With this way you can still use shell variables to construct the command. e.g.:
echo "rm -r $oldbackup/*" | ssh r#host sh

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