Cron mode security

[Asenar]

This PR replace the #46 «mode cron + base config in .example file»

Changes:

• Moved conf/esm.config.json to conf.esm.config.json.example
• Moved all commands into configuration file
• Improved Config class
• Added Misc::exec, Misc::shellexec, Misc::ago
• Added last_sftp_login information
• Added cron mode

Theses are the same commits with some fix due to the rebase. I removed the commit 8cfbf82 Last login: Show more relevant information from @QuentinCG because the new version seemed to works fine (I just typed in a shell so maybe I'm wrong).

The main improvement is still the cron mode to give a more secure way to retrieve information.

Cron Mode

Installation

• In your conf/esm.config.json check the value of mode is set to cron. Any other value will make ezServerMonitor works as before.
• use crontab -e as root to execute the script cron/cron-monitoring every 5 minutes (or more, or less, according to the precision you want).

The cron script run each libs/*.php file and store the result in cache file. Alternatively, you can run each php script separately.

Usage

just open the main index.php into a browser, the interface will show you the last cron update

[QuentinCG]

I'll have a look and give my feedback, it seems promising ;)

[Asenar]

To be more precise, it's about the commit 2866dfb (18 months ago) where you made this change:

-    if (!(exec('/usr/bin/lastlog --time 365 | /usr/bin/awk -F\' \' \'{ print $1";"$5, $4, $8, $6}\'', $users)))
+    if (!(exec('/usr/bin/lastlog --time 365 | /usr/bin/awk -F\' \' \'{ print $1" ("$3");"$5, $6, $9, $7}\'', $users)))

But the current master contains this :

if (!(exec('/usr/bin/lastlog --time 365 | awk \'{ printf $1";"; for (i=4; i<NF; i++) printf $i" "; print $NF; }\'', $users)))

I compared the 3 command and found than the newest «official version» was better (with my local config, debian 9) I didn't checked anywhere else.

By the way about that unix command, it tells me locally my last connection was the 22th may (and not today), but from the server I installed ezWeb I have more accurate dates :)