Major security and usability flaw in Linux (root privileges and sudoers, folder access restriction)
Alright, let me give you the context. I am a business owner with strong technical background, say a programmer, though not an advanced system administrator. I've bought a VPS server where I want to host several applications and webpages. One of the apps consists of backend, admin frontend and user frontend, another one is just backend and frontend. So 5 different programmers develop those apps. From time to time, as the development takes its place, those programmers need to install and upgrade some packages, modify system configs and so on, i.e. they need ssh access and some root privileges.
And here is the tricky part. It is obvious that I don't want them to see and gain access to the folders they are not supposed to see, i.e. the devs of the first app shouldn't have access to the folders of the second app and vice versa. Moreover the backend dev of the first app shouldn't have access to the frontend folders of the same app and the same goes for the second app. Also I would like to restrict access for them to certain commands like visudo or reboot, so they wouldn't be able to lock me out of my own server or reboot it without my consent.
Now, if I give them sudo privileges for them to be able to run administrative tasks needed for their development - then they have access to everything and it becomes practically impossible to restrict access for them to certain folders and commands. On the other hand if I DON'T give them sudo privileges, then it becomes a huge pain for me to every time install packages and give them access to certain files and commands they need to continue development. There are over 1500 commands and the corresponding number of system files in Linux they could potentially need access to, so it's very VERY unconvenient for me to spend so much time to administer the VPS, especially getting the fact that I'm not a very advanced system administrator and I don't have much time because I need to run my business.
There are already numerous posts and threads on the Internet where people try to find solutions to somewhat close problems like these: One, Two, Three, Four, Five, Six, Seven, Eight, Nine, and they still have no reasonable solutions to them, only those that involve some supercomplex activities and anyway not giving a needed result.
So from my point of view as a business owner it should be something like this: there is a root user who can do everything. He can create admins and define access rights for them, for example in that very sudoers file. Then it's his decision whether to give access to an admin to the sudoers file itself and any of the folders and commands of his choice. For example an admin could be able to run any command in the system except "reboot" and "visudo" and he can access all files and folders except /etc/sudoers and say /var/www/private_folder even WITH sudo privileges invoked (meaning he can't even copy those files, overwrite them, chmod and chown them and so on, i.e. access them with any command).
That would immediately make the whole system administration A LOT more easier and logical, eliminating the need for complex solutions like chroot jails, separate bash environments, splitting servers into virtual machines, using containers and so on. And it's so simple, a matter of a couple of conditions in the code, if I understand it correctly from a developer's perspective. Also, I want to be in control of my VPS, not having to trust any other third person believing he/she won't steal my information and/or destroy my whole system either by making a mistake or intentionally and basically it can be considered as a serious security vulnerability from a certain point of view.
This seems so obvious and logical for me, that I was really discouraged and embarrassed that it's really isn't like that in Linux. Maybe 20 years ago when Linux was created it was enough to have only a root and sudoers and the rest of users to accomplish tasks they had at that time, but today everything goes a bit different way already and that archaic approach is not usable anymore.
Of course I realize I can understand something wrong and there is a strong reason why it has to be as it is, then please let me know what is a correct and easy way of solving my problem described above without a need to build a behemoth on my VPS or manually administering it all the time by myself. After all it should be user-friendly, right? Now it's not.
On the other hand if there is no such a solution, then I would really be willing to even pay someone who could implement some kind of a patch or a package that will allow to solve this problem.
Please also let me know what do you think of the described issue and if you think it should be fixed in Linux architecture. Maybe we should ask Linus Torvalds about that?