Execure commands with PHP, how?

Haseldow

Hi,

I'm working on a page that retrieves processor load logs from windows and linux servers and displays them graphically using JpGraph. Windows servers use Perfmon to produce logs and the webserver gets the logs via samba mount. Linux servers use Sar for the log and retrieves the log via nfs mount. There are about 40 windows and linux servers in the environment that can be monitored one at a time using the page.

Everything works fine and I'm quite happy with the code. Now I wish to optimize it a bit. Currently the administrator using this page has to manually mount the smb/nfs shares and also create a folder to /mnt/<servername> for new servers addad to our environment.

The question is: What would be the easiest way to create the folder in /mnt/ if it doesn't allready exist and mount the smb/nfs share if it isn't mounted. I do have a bit of code that checks if the folder (/mnt/$servername exists or if the share is mounted. It currently returns $error=1 (if the folder doesn't exist) or $error=2 (if it isn't mounted). And I really wouldn't want to run apache with root privileges 😉 .

Regards,
Haseldow

bernouli

to execute programs with php use the function

system() or
passthru() or
exec()

Haseldow

I tried to use exec(), but with poor results. Seems there's some problems with privileges. I guess that exec() is run as nouser?

bernouli

I used exec() it gave me some errors,
I try passthru() it works fine,
to create directory /mnt i think you must run the apache with root privileges

daveyboy

You'll have to be root to create a file in /mnt, unless you set it to 777 or group nogroup, which is stupid. Most linux boxes won't allow you to SUID any script files, either.

You're best bet would be to create the directories in /mnt beforehand (though you can mount in any directory anywhere), and to make sure the user nobody / apache has sufficient rights to mount the partitions, probably by tinkering with /etc/fstab.

Another possibility might be to run "su -c 'mkdir /mnt/dir; mount -t smbfs //server1/logs /mnt/dir'" through popen, and pass it the root password entered by the user, over https of course.

Haseldow

Got the folder creation to /mnt/ solved quite simply by mounting it to another directory.

But now for the samba mount part. The "su -c 'mount -t smbfs -o workgroup=<domain>,username=<user>,password=<passwd> //<servername>/<share> /<mountpoint>/'" sounds good, but I can't get it to work.

I tried something of the following:
$cmd="su -c 'mount ...blaablaa...'";
$doit=popen($cmd,"w");
fwrite($doit,$rootpass);
pclose($fp);

And some variables of the above, but didn't seem to get it to work. What am I doing wrong? (or could you give simple example please)

Thank you for the help so far btw.

daveyboy

I had a try with Python (which is much better for processes) and got the following message: 'standard in must be a tty'. So, there's the problem. I don't know what the solution might be. sudo?

You may well have to let apache do it, not root. perhaps you could delegate retrieving the log files to a root cron job?

Haseldow

The problem is that the logs should only be retrieved when the server in question is being monitored. The logfiles must be up to date or no more than 5 minutes late. Also there's around 40 servers to monitor which all have one day logrotate. Usually 5 weeks worth of logs are being monitored at the same time, so that would make 1400 logs. So retrieving the logs as a cron job is pretty much out of the question.

But I could code PHP to make a mount script that cron executes. So that any new server added to the list of monitored server would be mounted and if any mount for some reason would have become unmounted, it would mount those too.

But I'd much rather have it done without cron so that any new server would be instantly mounted when being added to the list or when a server is being monitored that has lost its mount.

I tried sudo earlier but that didn't help. There must be something similar (to popen or su/sudo) to try out? Maybe something like swat (samba web administration tool) could do the trick?

daveyboy

a samba server can be told to run certain scripts when a share is accessed, yes. the classic example is running mount as root when a user accesses the cdrom of the server.

I think you should consider going beyond web-scripts and write a custom command-line script to run constantly in the background as root, and download the log files when requested by your web-scripts. A daemon running as root would do the job much better. Your could control it over a socket or named pipe.