So in the terminal I access the remote host through ssh -p then once I'm in i have to cd /directory1/directory2/. Then I want to find the latest directory which I do using ls -td -- */ | head -n 1 then using this I want to cd into that and tail -n 1 file1
All these commands work in the terminal but I want to automate it to where I can just type ./tailer.sh and have that be output.
Any ideas would be appreciated.
The shell script tailer.sh can look something like this
#!/bin/bash
ssh -p <PORT> <HOST_NAME> '( cd /directory1/directory2/ && LATEST_DIR=$(ls -td -- */ | head -n 1) && cd ${LATEST_DIR} && tail -n 1 file1 )'
Then give execute permissions to tailer.sh using chmod u+x tailer.sh
Run the script using ./tailer.sh
Related
I cannot figure out what's wrong with my bash script. When I run it in terminal, command by command run every command separately in terminal, it works.
#!/bin/bash
sudo su <<EOF
mkdir /home/ubuntu/backup/
cp "$(ls -t /usr/lib/unifi/data/backup/autobackup | head -1)" /home/ubuntu/backup/
curl --insecure --user root:password -T "$(ls -t /home/ubuntu/backup/ | head -1)" sftp://vps2.duckdns.org:/root/backup.unf
EOF
However, when I run the above bash script, give me plenty of erros
bash -v test.sh
#!/bin/bash
sudo su <<EOF
mkdir /home/ubuntu/backup/
cp "$(ls -t /usr/lib/unifi/data/backup/autobackup | head -1)" /home/ubuntu/backup/
curl --insecure --user root:password -T "$(ls -t /home/ubuntu/backup/ | head -1)" sftp://vps2.duckdns.org:/root/backup.unf
EOF
ls: cannot access '/usr/lib/unifi/data/backup/autobackup': Permission denied
ls: cannot access '/home/ubuntu/backup/': No such file or directory
cp: cannot stat '': No such file or directory
curl: (78) Could not open remote file for reading: SFTP server: No such file
Any help will be very much appreciated!
TIA
It's trying to execute the command substitutions in the original shell, which runs with the regular user's permissions. They need to be executed by su. Quote the EOF token to prevent expansions in the here-document.
sudo su <<'EOF'
I want to execute cd and scp commands on a remote server which have to be logged in with a different sudo user. Below code snippet asks for the password(echos on screen) for my user but hangs there. It doesn't execute cd
#!/bin/bash
server=myserver.com
ssh $server 'sudo -S -u <user> -i; cd dir1/dir2/; scp file1 user#local-sever'
The issue is that you have a semi colon before cd and so sudo has no command to execute. Remove the ; and it should work:
ssh $server 'sudo -S -u <user> -i scp dir1/dir2/file1 user#local-sever'
There are several ways to address this, but most boil down to wrapping up the commands into a set of instructions. Raman's solution is good since it handles the issue by using full paths, but sometimes that isn't an option. Here's another take -
Assuming your command list can afford the quotes, I like here-strings.
ssh -t sa-nextgen-jenkins.eng.rr.com <<< "
echo 'set -x; cd /tmp; whoami; touch foo; ls -l foo; rm -f foo;'|sudo -iSu user
"
If you need the quotes, try a here-doc.
ssh -t sa-nextgen-jenkins.eng.rr.com <<END
echo 'set -x; echo "$RANDOM"; cd /tmp; whoami; touch foo; ls -l foo; rm -f foo;'|sudo -iSu $user
END
You can also write a small script that has arbitrarily complex commands and scp it over, then use a remote ssh call to execute it as the relevant user.
Shell script needs to
ssh to Host2 from Host1
cd /test/test1/log
grep logs.txt for string error
write the grepped output to a file
and move that file to Host1
This can be accomplished by specifying the -f option to ssh:
ssh user#host -f 'echo "this is a logfile">logfile.txt'
ssh user#host -f 'grep logfile logfile.txt' > locallogfile.txt
cat locallogfile.txt
An example using a different directory and cd changing directories to it:
ssh user#host -f 'mkdir -p foo/bar'
ssh user#host -f 'cd foo/bar ; echo "this is a logfile">logfile.txt'
ssh user#host -f 'cd foo/bar ; echo "this is a logfile">logfile.txt'
ssh user#host -f 'cd foo/bar ; grep logfile logfile.txt' > locallogfile.txt
cat locallogfile.txt
I am trying to update the crontab file of 1000+ systems using a for loop from jump host.
The below doesn't work.
echo -e 'pass365\!\n' | sudo -S echo 'hello' >> /var/spool/cron/root
-bash: /var/spool/cron/root: Permission denied
I do have (ALL) ALL in the sudoers file.
This is another solution;
echo 'pass365\!' | sudo -S bash -c 'echo "hello">> /var/spool/cron/root'
The below worked for me.
echo 'pass365\!' | sudo -S echo 'hello' | sudo -S tee -a /var/spool/cron/root > /dev/null
Problem 1: You are trying to send the password via echo to sudo.
Problem 2: You can't use shell redirection in a sudo command like that.
Between the two of these, consider setting up ssh public key authorization and doing
ssh root#host "echo 'hello' \>\> /var/spool/cron/root"
You may eventually get sudo working but it will be so much more pain than this.
From a previous question, I have found that it is possible to run a local script on a remote host using:
ssh -T remotehost < localscript.sh
Now, I need to allow others to specify the directory in which the script will be run on the remote host.
I have tried commands such as
ssh -T remotehost "cd /path/to/dir" < localscript.sh
ssh -T remotehost:/path/to/dir < localscript.sh
and I have even tried adding DIR=$1; cd $DIR to the script and using
ssh -T remotehost < localscript.sh "/path/to/dir/"
alas, none of these work. How am I supposed to do this?
echo 'cd /path/to/dir' | cat - localscript.sh | ssh -T remotehost
Note that if you're doing this for anything complex, it is very, very important that you think carefully about how you will handle errors in the remote system. It is very easy to write code that works just fine as long as the stars align. What is much harder - and often very necessary - is to write code that will provide useful debugging messages if stuff breaks for any reason.
Also you may want to look at the venerable tool http://en.wikipedia.org/wiki/Expect. It is often used for scripting things on remote machines. (And yes, error handling is a long term maintenance issue with it.)
Two more ways to change directory on the remote host (variably):
echo '#!/bin/bash
cd "$1" || exit 1
pwd -P
shift
printf "%s\n" "$#" | cat -n
exit
' > localscript.sh
ssh localhost 'bash -s "$#"' <localscript.sh '/tmp' 2 3 4 5
ssh localhost 'source /dev/stdin "$#"' <localscript.sh '/tmp' 2 3 4 5
# make sure it's the bash shell to source & execute the commands
#ssh -T localhost 'bash -c '\''source /dev/stdin "$#"'\''' _ <localscript.sh '/tmp' 2 3 4 5