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Čamo
Asked: 2021-02-05 03:13:11 +0800 CST

Why does this script running su never seem to terminate if I change user inside the script?

  • 772

I have a really simple bash script with 5 commands running under the root user. If I run commands manually one by one everything works - no problem. But as I run it as my-deploy.sh file via command

bash /root/custom-scripts/deploy/my-deploy.sh 2>> /var/log/www-deploy/tatrytec.eu.log

it seems like endless process. Here is the script:

#!/bin/bash
# Run this script as bash command like: bash create-apache-site.sh

cd /var/www/html/tatrytec.eu

git pull

# Change user bacause of composer install warrning
su vlado

composer install  --no-scripts

npm install --production

It starts to run and I can see result of git pull in terminal. But then it dies without any error and it is still running. I can stop it via ctrl+Y. I thing something is wrong with that user but as I wrote before if I run commands one by one it works. I dont understand. Can somebody tell me what could be the problem? Thanks.

bash

4 Answers

    1. su vlado will need a password unless run as root.
    2. su vlado will wait for input
    3. commands after su valdo are not executed inside su, but after exiting su valdo

    what happen

    cd /var/www/html/tatrytec.eu  # change dir

git pull # pull git repos

# Change user bacause of composer install warrning
su vlado # either ask password or wait for input

composer install  --no-scripts # if this get executed, you are no longer as vlado
    • the key point is that su vlado will fork a new shell, that will ignore (as is) following line in original bash script.
    • when copy/pasting you don't have that limitation (as you copy inside vlado's new shell)

    I try to explain in more details which user/what happen

    cd /var/www/html/tatrytec.eu  # ROOT change dir

git pull # ROOT pull git repos

# Change user bacause of composer install warrning
su vlado # VLADO wait for input
new shells as VLADO> sample command
new shells as VALDO> exit

composer install  --no-scripts # ROOT run composer

    proposed correction

    as root

    #!/bin/bash
# Run this script as bash command like: bash create-apache-site.sh

cd /var/www/html/tatrytec.eu

git pull

# Change user bacause of composer install warrning
su vlado  <<EOF

composer install  --no-scripts

npm install --production

EOF

    where

    • su vlado << EOF ... EOF will feed all lines to su vlado
    • 14

  2. Use this instead:

    #!/bin/bash
# Run this script as bash command like: bash create-apache-site.sh

cd /var/www/html/tatrytec.eu

git pull

# Change user bacause of composer install warrning
su vlado -c 'composer install  --no-scripts; npm install --production'

    The -c or --command option for su allows you to run a command.

    • 10

  3. I guess su vlado needs a password to be typed in.

    You could use sudo and make it not need a password for specific commands by modifying /etc/sudoers

    • 1
  4. Best Answer

    You seem to want to run the last lines in your script as the user vlado. There is a clean way to do that:

    sudo -u vlado  your_command

    So the last few lines of your script will look like this:

    sudo -u vlado composer install --no-scripts
sudo -u vlado npm install --production
    • 1