Sudo/ko

The command provides a simple and secure way to configure privilege escalation — i.e., letting normal users execute certain (or even all) commands as  or another user, either with or without giving a password.

When you want some people to perform certain administrative steps on your system without granting them total root access, using is your best option. With you can control who can do what. This guide offers you a small introduction to this powerful tool.

This article is meant as a quick introduction. The package is a lot more powerful than what is described here. It has special features for editing files as a different user, running from within a script (so it can background, read the password from standard in instead of the keyboard, ...), etc.

Please read the and  manual pages for more information.

활동 기록
One additional advantage of is that it can log any attempt (successful or not) to run an application. This is very useful if you want to track who made that one fatal mistake that took you 10 hours to fix :)

권한 부여
The package allows the system administrator to grant permission to other users to execute one or more applications they would normally have no right to. Unlike using the  bit on these applications  gives a more fine-grained control on who can execute a certain command and when.

With you can make a clear list of who can execute a certain application. If you set the setuid bit on an executable, any user would be able to run the application (or any user of a certain group, depending on the permissions used). With you can (and probably should) require the user to provide a password in order to execute the application.

The configuration is managed by the  file. This file should never be edited through or, or any other editor you would normally use. When you want to alter the file, you should always use. This tool makes sure that no two system administrators are editing this file at the same time, preserves the permissions on the file, and performs some syntax checking to make sure you make no fatal mistakes in the file.

기본 문법
The most difficult part of is the  syntax. The basic syntax is as follows:

This line tells that the user, identified by   and logged in on the system , can execute the command   (which can also be a comma-separated list of allowed commands).

A more real-life example might make this more clear: To allow the user to execute  when he is logged in on :

The user name can also be substituted with a group name, in which case the name is prefaced by a  sign. For instance, to allow any one in the group to execute :

To enable more than one command for a given user on a given machine, multiple commands can be listed on the same line. For instance, to allow to not only run  but also  and  as root:

You can also specify a precise command line (including parameters and arguments) not just the name of the executable. This is useful to restrict the use of a certain tool to a specified set of command options. The tool allows shell-style wildcards (AKA meta or glob characters) to be used in path names as well as command-line arguments in the sudoers file. Note that these are not regular expressions.

Here is an example of from the perspective of a first-time user of the tool who has been granted access to the full power of :

The password that requires is the user's own password. This is to make sure that no terminal that you accidentally left open to others is abused for malicious purposes.

LDAP 기본 문법
The  and   USE flags are needed for the LDAP support.

LDAP에 sudo를 사용하면 마찬가지로 LDAP 서버의 설정을 읽습니다. 따라서 다음 두개의 파일을 편집해야합니다.

또한 sudo 에 다음 LDAP 항목을 추가해야 합니다.

sudoer LDAP 설정은 다른 설정을 하는 파일과 비슷합니다. 아래 링크에 있는 sudo LDAP 글을 더 읽어보십시오.

별칭 사용
좀 더 거대한 환경에서는 모든 사용자(또는 호스트, 명령)를 계속해서 적어넣어야 하는데 그걸 다 하기엔 벅찹니다. 관리를 쉽게 하기 위해 aliases를 정의할 수 있습니다. aliases를 선언하는 형식은 약간 단순합니다:

어디에 있든, 항상 동작하는 별칭은  입니다(별칭인 것과 아닌 것을 쉽게 구분하기 위해 대문자 사용을 추천합니다). 확실히 짐작한 바와 같이  별칭은 모든 설정에서 쓸 수 있는 별칭입니다.

A sample use of the  alias to allow any user to execute the  command if he is logged on locally is:

Another example is to allow the user to execute the  command as root, regardless of where he is logged in from:

More interesting is to define a set of users who can run software administrative applications (such as and ) on the system and a group of administrators who can change the password of any user, except root!

비 루트 실행
It is also possible to have a user run an application as a different, non-root user. This can be very interesting if you run applications as a different user (for instance for the web server) and want to allow certain users to perform administrative steps as that user (like killing zombie processes).

에는 명령을 나열하기 전에  과   사이에 사용자를 나열하십시오:

For instance, to allow to run the  tool as the  or  user:

With this set, the user can run to select the user he wants to run the application as:

지시어를 활용하면 프로그램을 실행할 사용자의 별칭을 설정할 수 있습니다. 앞서보았던  지시자에게도 이러한 활용법은 완전히 같습니다.

암호 및 기본 설정
By default, asks the user to identify himself using his own password. Once a password is entered, remembers it for 5 minutes, allowing the user to focus on his tasks and not repeatedly re-entering his password.

물론 이 동작을 바꿀 수 있습니다: 에서  지시어로 사용자에 대한 기본 동작 설정을 바꿀 수 있습니다.

기본 5분값을 0(기억하지 않음)으로 바꾸려면:

로 설정하면 (시스템을 다시 부팅하기 전까지) 암호를 무한대 시간동안 기억합니다.

A different setting would be to require the password of the user that the command should be run as and not the users' personal password. This is accomplished using. In the following example we also set the number of retries (how many times the user can re-enter a password before fails) to   instead of the default 3:

그래픽 도구를 실행할 수 있게  변수 설정을 유지하는 또 다른 재밌는 기능도 있습니다:

You can change dozens of default settings using the  directive. Fire up the manual page and search for.

허나 어쨌든간에 암호를 제공하지 않고 명령 세트를 실행할 수 있게 하려면, 다음과 같이  지시자를 붙여 명령 기입을 시작해야합니다:

배시 자동 완성
sudo에 bash 명령 완성 기능을 사용하려는 사용자는 다음 명령을 한번 실행하십시오.

Z쉘 명령 완성
sudo에 zsh 명령 완성 기능을 사용하려는 사용자는 와 에 각각 다음 내용을 설정할 수 있습니다

위 내용으로 바꾸면,, , 위치에 있는 값은 'sudo' 다음에 놓은 명령에 대한 명령 완성 기능을 쉘에서 사용할 수 있습니다.

권한 확인
To inform yourself what your capabilities are, run :

에 암호를 입력할 필요가 없는 명령이 있다면, 항목에 있는 명령에 암호를 요구하지 않습니다. 그렇지 않아 항목에 없어 기억하지 않으면 암호를 물어봅니다.

암호 입력 제한 시간 미리 연장
By default, if a user has entered their password to authenticate their self to, it is remembered for 5 minutes. If the user wants to prolong this period, he can run to reset the time stamp so that it will take another 5 minutes before  asks for the password again.

The inverse is to kill the time stamp using.