CODEWITHSUNDEEP
bashsshkvm
user12897075
user12897075

Reputation:

Bash script doesn't exit SSH host after execution

I am running a CentOS 7 VM that I want to set a static IP to.

Running SSHPASS=password sshpass -e ssh -tt -o "StrictHostKeyChecking no" [email protected] 'echo "password" | sudo -Sv && bash -s' < script.sh executes all the commands in script.sh but, after completion, the terminal stays inside the VM, irregardless of whether I have the exit command at the end of my bash script or not.

The reason for piping my password is to skip entering it in the terminal.

Here is my bash script:

sudo cp /etc/sysconfig/network-scripts/ifcfg-ens3  /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo sed -i 's/BOOTPROTO="dhcp"/BOOTPROTO="static"/g' /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo sed -i 's/NAME="ens3"/NAME="ens3:0"/g' /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo sed -i 's/DEVICE="ens3"/DEVICE="ens3:0"/g' /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'PEERDNS="yes"' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'IPADDR=192.168.122.201' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'NETMASK=255.255.255.0' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'GATEWAY=192.168.122.1' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo systemctl restart network
exit

Ideally, I would like to execute these commands in the same script but I can't seem to figure out what the problem is.

Interesting note: if I run cat script.sh | SSHPASS=password sshpass -e ssh -tt [email protected] 'echo "password" | sudo -Sv && bash -s' the console stops on the exit command (not inputted) and if I press enter to input it, the VM stalls and I can only exit with CTRL+C.

UPDATE If I run ./script.sh that has the following contents...

ssh -tt [email protected] 'echo "password" | sudo -Sv && bash -s' << EOF
echo
sudo cp /etc/sysconfig/network-scripts/ifcfg-ens3  /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo sed -i 's/BOOTPROTO="dhcp"/BOOTPROTO="static"/g' /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo sed -i 's/NAME="ens3"/NAME="ens3:0"/g' /etc/sysconfig/network-scripts/ifcfg-ens3:0
sudo sed -i 's/DEVICE="ens3"/DEVICE="ens3:0"/g' /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'PEERDNS="yes"' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'IPADDR=192.168.122.201' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'NETMASK=255.255.255.0' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
echo 'GATEWAY=192.168.122.1' | sudo tee -a /etc/sysconfig/network-scripts/ifcfg-ens3:0
exit
EOF

Everything works. Which leads me to believe that the problem is related to sudo systemctl restart network. Confirmed by adding sudo systemctl restart network; exit at the end of the script. Maybe it has something to do with the nature of this command.

Upvotes: 1

Views: 1845

Answers (2)

chepner
chepner

Reputation: 530922

Your goal is to edit a file in your VM. Neither of your commands runs anything except echo "password" on the VM.

What (should) work

The following isn't tested. What you want is to have sudo run remotely, reading from the script that ssh passes across the connection via standard input. Something like

SSHPASS=password sshpass -e ssh [email protected] \
  '{ echo "password"; cat; }| sudo -Sv bash' < script.sh

The cat ensures that everything ssh sends over the connection is read by sudo after it reads the password from standard input.

What was wrong

Your first command

SSHPASS=password sshpass -e ssh \
                         -tt \
                         -o "StrictHostKeyChecking no" \
                         [email protected] 'echo "password" |
  sudo -Sv &&
bash -s' < script.sh

starts by running sshpass. It logs into the remote host, runs echo "password", then logs out. That output is piped to sudo -Sv, which, having no command to run, just ignores its input and exits successfully. Then bash runs the code read from your script locally.

Your second command, 

cat script.sh | 
  SSHPASS=password sshpass -e ssh -tt [email protected] 'echo "password" |
  sudo -Sv &&
bash -s'

pipes the contents of your script to sshpass, which again logs into the remote host and executes the command, ignoring your script, and exiting. sudo then ignores its input and exits successfully, starting bash -s which blocks, waiting for input.

Incidentally, your script can be simplified to

cd /etc/sysconfig/network-scripts
{
  sed -e 's/BOOTPROTO="dhcp"/BOOTPROTO="static"/g' \
      -e 's/NAME="ens3"/NAME="ens3:0"/g' \
      -e 's/DEVICE="ens3"/DEVICE="ens3:0"/g' ifcfg-ens3
  echo 'PEERDNS="yes"'
  echo 'IPADDR=192.168.122.201'
  echo 'NETMASK=255.255.255.0'
  echo 'GATEWAY=192.168.122.1'
} > ifcfg-ens3:0
systemctl restart network

No sudo (because the script is executed with sudo), and one sed command (reading from the original file) and multiple echo all writing to the same output file.

Upvotes: 1

Arpit Jain
Arpit Jain

Reputation: 1315

Please try something like this

ssh -t [email protected] << EOF
 command1
 command2
 exit
EOF

OR

SSHPASS=password sshpass -e ssh -tt -o "StrictHostKeyChecking no" [email protected] 'echo "password" | sudo -Sv && bash -s' < script.sh && exit

Upvotes: 0

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