Once at your Moodle base folder, just:
- 
/usr/bin/php admin/cli/maintenance.php --enable
 - 
git pull
 - 
/usr/bin/php admin/cli/maintenance.php --disable
 - 
Log in to the site, as administrator, and follow the web steps to update database, etc.
 
Once at your Moodle base folder, just:
/usr/bin/php admin/cli/maintenance.php --enable
git pull
/usr/bin/php admin/cli/maintenance.php --disable
Log in to the site, as administrator, and follow the web steps to update database, etc.