sudoless passwordless script

Question

I want to make a sudoless passwordless script which doesn't prompt for password to any user executing that script.

Problem: my script contains rsync utility to send files to a backup server, but i always get permission denied error when the folder which needs to be send contains some files for which the access is set to none. whereas other files are also owned by root but their access is set to read only. I'm using public key authentication to send files to destination/backup so that it doesn't prompt for password input but it cannot send access protected files like above without sudo and password input.

Tries: I tried https://unix.stackexchange.com/a/229653/332764 this solution but it is not working. Still same error is there.

EDIT: sudoers file

#
# This file MUST be edited with the 'visudo' command as root.
#
# Please consider adding local content in /etc/sudoers.d/ instead of
# directly modifying this file.
#
# See the man page for details on how to write a sudoers file.
#
Defaults    env_reset
Defaults    mail_badpass
Defaults    secure_path="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/snap/bin"

# Host alias specification

# User alias specification

# Cmnd alias specification

# User privilege specification
root    ALL=(ALL:ALL) ALL

# Members of the admin group may gain root privileges
%admin ALL=(ALL) ALL

# Allow members of group sudo to execute any command
%sudo   ALL=(ALL:ALL) ALL

ortega ALL=(ALL) NOPASSWD: /home/usr/path/transmit_ckpnt.sh
# See sudoers(5) for more information on "#include" directives:

#includedir /etc/sudoers.d

Answer 1

You have a few options:

1. Setup a root crontab job to do a chown (Have root do a job periodically)
2. Use docker privilege escalation to chmod your file in a container with a mounted volume.
3. Devise a non-root task equivalent to the root one you are doing

1. Root crontab

A crontab schedules commands execution at Specified time or time interval. Here you could create a root crontab with the command sudo crontab -u root -e. This will open you into an editor to write your crontab: best practices

2. Docker privilege escalation

This method requires either already being root or being part of a machines docker group. As a non-root user who is a member of the docker group you have the ability to mount any directory as a volume within a docker container. Within the container you are root, and changes you make to the mounted volume will persist. Simply chmod the file in the container.

File Permissions

• Use chown and chmod to change file-system permissions.

Password-less rsync

• The rsync command supports using ssh-keys which allow you to log into other machines password-less after a quick one time key-exchange.

If you cannot chown or chmod a file because of a permission error, that is because a user with more permissions than you (root) will need to help you change the file permissions.

Answer 2

I use this Sudoless no password bash script

1. Open the /etc/sudoers file (as root, of course!) by running:
sudo nano /etc/sudoers

2. At the end of the /etc/sudoers file add this line:
username ALL=(ALL) NOPASSWD:ALL