95 lines
3.4 KiB
Markdown
95 lines
3.4 KiB
Markdown
# iRedMail Easy: Setup sudo for deployment
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[TOC]
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## What is `sudo` (Linux) and `doas` (OpenBSD)
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From [wikipedia](https://en.wikipedia.org/wiki/Sudo):
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> sudo is a program for Unix-like computer operating systems that allows users
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> to run programs with the security privileges of another user, by default the
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> superuser `root`. It originally stood for "superuser do" as the older versions
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> of sudo were designed to run commands only as the superuser. However, the later
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> versions added support for running commands not only as the superuser but also
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> as other (restricted) users, ...
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>
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> Unlike the similar command `su`, users must, by default, supply their own
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> password for authentication, rather than the password of the target user.
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> After authentication, and if the configuration file, which is typically
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> located at `/etc/sudoers`, permits the user access, the system invokes the
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> requested command. The configuration file offers detailed access permissions,
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> including enabling commands only from the invoking terminal; requiring a
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> password per user or group; requiring re-entry of a password every time or
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> never requiring a password at all for a particular command line. It can also
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> be configured to permit passing arguments or multiple commands.
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OpenBSD uses its own sudo-like program for this purpose, it's called `doas`
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which means *__execute commands as another user__*.
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With the iRedMail Easy, you can deploy iRedMail by connecting to
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target server (via ssh) as a non-privileged user (e.g. user `iredmail`) which
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is allowed to run command as `root` with `sudo`.
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## Linux: Setup sudo
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Let's say you're going to connect as user `iredmail`:
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* Run command `visudo` as root user.
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Although you can edit sudo config file `/etc/sudoers` with your favourite
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text editor, but `visudo` will help check syntax while saving changes. this
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is helpful to avoid some mistakes like misspelled username, or any other
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keyword.
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* Add lines below at the end, save your changes and quit `visudo`.
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```
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# Allow user `iredmail` to run all commands without typing its own password.
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iredmail ALL=(ALL) NOPASSWD: ALL
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# We're going to connect without a real tty, below setting will speed up the
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# iRedMail deployment process.
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Defaults:iredmail !requiretty
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```
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To verify the sudo configuration, please login as user `iredmail` first, then run
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command:
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```
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sudo ls /root/
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```
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If sudo is correctly configured, it will show you list of files under `/root`
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directory.
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## OpenBSD: Setup doas
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Let's say you're going to connect as user `iredmail`.
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Append line below to file `/etc/doas.conf` (if this file doesn't exist, please
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create it manually):
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```
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permit nopass iredmail as root
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```
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To verify the sudo configuration, please login as user `iredmail` first, then run
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command:
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```
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doas ls /root/
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```
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If sudo is correctly configured, it will show you list of files under `/root`
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directory.
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## References
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* Linux `sudo`:
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* [sudo manual page](https://www.sudo.ws/man/1.8.3/sudo.man.html)
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* [10 Useful Sudoers Configurations for Setting ‘sudo’ in Linux](https://www.tecmint.com/sudoers-configurations-for-setting-sudo-in-linux/)
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* [Difference Between su and sudo and How to Configure sudo in Linux](https://www.tecmint.com/su-vs-sudo-and-how-to-configure-sudo-in-linux/)
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* OpenBSD `doas`:
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* [doas(5) manual page](https://man.openbsd.org/doas.conf.5)
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* [doas(1) manual page](https://man.openbsd.org/doas.1)
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