Take the 2-minute tour ×
Server Fault is a question and answer site for professional system and network administrators. It's 100% free, no registration required.

I want to be able to restart services from a php-script. running under the www-user account.

What's the preferred way to perform these actions?

I recon I can place create a file with que'd commands, read by CRON, but the solution itches.

What I'm thinking of is a tiny service, running under root, allowing predefined "methods" so arbitrary root actions cannot be executed.

Any tool out there for this?

share|improve this question
    
@MadHatter, Mona Lisa sends her greetings, ;-) –  user65297 Oct 22 '11 at 10:13
add comment

2 Answers 2

up vote 27 down vote accepted

You could reinvent the wheel, but honestly, I use passwordless sudo for this. For example, my monitoring system needs to be able to run a command to check the hardware RAID. This requires root privilege, but I don't want to run the whole monitoring system as root, so instead I have in sudoers a line that says

nagios  ALL=(root) NOPASSWD: /usr/lib/nagios/plugins/check_md_raid

and then run the command sudo /usr/lib/nagios/plugins/check_md_raid as the monitoring user, when I need to check the RAID.

You could have a sudoers line that said

www-user    ALL=(root) NOPASSWD: /etc/rc.d/init.d/myservice

then have php execute sudo /etc/rc.d/init.d/myservice restart.

share|improve this answer
2  
This is the way to go IMO. I used this process for a similar task. It's been in production for over 3 years now. Nothing has ever failed and the security risk is almost non-existent as long as you protect the PHP code that triggers it properly with your application logic. –  Andrew Oct 8 '11 at 16:02
1  
Thanks, sudoers new to me and bang on target. @Andrew, thanks for the additional info. –  user65297 Oct 8 '11 at 20:16
1  
user65927, forgive me if this isn't news to you, but local etiquette is that when you have a satisfactory answer to a question you accept it by clicking on the tick outline next to it. –  MadHatter Oct 8 '11 at 23:41
1  
You may also need to comment out the line "Defaults requiretty" in your sudoers file. This step has gotten me a few times. (E.g. change "Defaults requiretty" to "#Defaults requiretty") –  steve.lippert Oct 10 '11 at 16:13
add comment

Take a look at sudo: it allows to specify actions that can be performed as another user (root in your case).

You can for example add to your/etc/sudoers (don't edit the file directly use visudo)

www-user-account ALL= NOPASSWD: /usr/bin/mypredefinedaction

See man sudo for the details and syntax of the file

share|improve this answer
2  
be VERY careful when you edit the /etc/sudoers file. If it is in any way syntactically incorrect, changing it back is a nightmare b/c you need to sudo back into it, but you can't b/c you just wiped out sudo. You end up having to use a rescue CD/DVD and mount the partition manually. –  puk Nov 4 '11 at 7:24
1  
@puk Actually to edit shudders you need root access and in case the file is damaged you can log in as root and then restore it (from a backup copy) or fix it manually. visudo also performs sanity checks on the file before writing it. –  Matteo Nov 4 '11 at 10:19
    
what is shudders? It's true visudo does sanity checks, but they don't help after the damage is done :P –  puk Nov 4 '11 at 10:24
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.