Table of Contents

netstat.php - simple network status

netstat.php is a PHP script intended to provide a simplified, easily comprehensible and aesthetically pleasing overview of the online status of hosts and services.

Background story

We use the usual suspects when it comes to network monitoring. There is lots of very good open source software which does all the tricks. However, I always missed a simple, intuitive interface with lots of green traffic lights which I could make available to my users (and clients). Of course, I looked for simple and freely available scripts but could not find any which did the job and still pleased my eyes. Eventually, I wrote my own.

netstat.php only checks whether a specific port is open. It can be configured to check for instance whether some software is listening on port 25 (for SMTP) but it cannot tell whether this software is still working1). Point is that we do not need more since we are running full-blown monitoring software anyway. In most cases, it is sufficient for my users to see a red light only when the network or the servers are down or the daemon is not running at all. And in general, an admin will2) know before users do.

Screenshot

This screenshot shows also a tooltip which is included as mouse-over in case of errors.

For an HTML example see netstat.php's main page.

Features

Instructions for use

netstat.php comes as a single PHP file. Download it, rename appropriately, edit the source code or create a configuration file to change settings, and have fun. Out of the box, the script looks for a configuration file named netstat.conf.php. It is recommended to put all settings into this file.

netstat.conf.php

Here is sort of a minimal example. For all supported settings see below.

<?php /* netstat.conf.php example */
$title = "Our network status";
$headline = $title;
$checks = array(
 'router.example.com|ping| ICMP ping (ping)',
 'www.mydomain.not  | 80 | WWW server (port 80)',
 'localhost         | 22 | SSH server (port 22)',
 '   Other checks   | headline',
 'www.example.com   | 80 | WWW server example.com' // no colon here!
)
$ping_command = '/usr/bin/ping -l3 -c3 -w1 -q';

$checks

netstat.txt

netstat.php can also be used to show an alert message. By default, the script looks for a file named netstat.txt and includes it. Use HTML for formatting your alert message. Example:

<p><b>Status as of 2009-10-26 11:47</b><br />
Mail services are currently down. On-site engineers are already investigating the cause
of this unexpected interruption. Further information will be provided in about 30 minutes.</p>

In order to disable the inclusion of the file either rename it or change its permissions.

All configuration variables

Here is a full example of a configuration file (except for $checks and $htmlheader):

<?php
/**
 * netstat.php - Settings example for $configfile with defaults (mostly)
 */
 
$configfile = 'netstat.conf.php'; // name of file where to put these variables
$error_reporting = 0; // See http://php.net/error_reporting
 
$title = "Our Network Status"; // page title
$headline = $title; // page headline
 
$alertfile = 'netstat.txt'; // extra alert file included in HTML + RSS
// $checks = allthemagic(); // See script or homepage for how to specify
 
$ping_command = 'ping -c3 -w1 -q'; // external command to use for ICMP ping
$ping6_command = 'ping6 -c3 -w1 -q'; // ditto for IPv6
$timeout = 4; // fsockopen timeout (sort of the sensitivity)
 
$progressindicator = TRUE; // show a simple progress indicator (req. Javascript)
$rssfeed = TRUE; // use to enable or disable RSS feeds (see also below)
 
$online = 'Online'; // strings for online and offline
$offline = 'Offline'; // note that by default these are used in CSS, too
 
$datetime = 'l, F j, Y, H:i:s T'; // date/time format; skipped if empty
 
$rssfeedurl = $_SERVER['SCRIPT_NAME'].'?rss'; // URL of RSS feed
$rsstitle = "RSS alert feed of $title"; // RSS feed title
$rssheader = '<link rel="alternate" type="application/rss+xml" '
        . "title=\"$rsstitle\" href=\"$rssfeedurl\" />"; // RSS header
$rsslink = $_SERVER['SCRIPT_NAME'].'?noprogress'; // RSS alert link
$rssdatetime = 'o-m-d H:i:s T'; // RSS date and/or time format
 
// $htmlheader = ... see script for a full example; note that by default it
//   uses other variables, too: $title, $rssheader, $online, $offline
 
$htmlfooter = "</div>\n</body>\n</html>"; // well, guess what :-)
 
// $version ... version of script, link to homepage and author

Download & source code

There are currently 3 variants of netstat.php. Choose the one that suits you best:

netstat-kiss.php Download (~ 8 KB) View source
netstat.php v0.15 Download (~12 KB) View source CHANGES.txt
netstat.php v1.x Hosted at GitHub View source Commit history

Final remarks

Requirements

For basic operation, the script mostly uses PHP's fsockopen(), which needs to be enabled. Unfortunately, some web hosting providers apparently disable this function.

For ICMP pings also exec() needs to be enabled which many providers disable, and a command line version of ping must be available.

Usage recommendations

Under certain circumstances, it might be better to not directly provide the PHP file to your users but instead create a static HTML file by means of e.g. a cronjob. Some of these situations are:

We installed netstat.php on a remote site where a cronjob runs

php5 netstat.php rss >rss.xml
php5 netstat.php noprogress >index.htm

The "noprogress" suppresses the Javascript progress indicator of netstat.php.

The actual script (shown below) does even more:

  1. The old status is saved to oldstatus.
  2. A static HTML version of netstat.php is saved to index.htm.
  3. A plain text version of index.htm is saved to netstat.ctl.
  4. If the new status is different from the old a message is sent.
#!/bin/bash
set -e
cd /directory_of_your_netstat.php_installation
 
# Save old status
cat index.htm >oldstatus.htm
cat netstat.ctl >oldstatus.ctl
 
# Retrieve or produce a static version of the netstat.php RSS alert feed
php5 netstat.php rss >rss.xml
 
# Retrieve or produce a static version of the netstat.php results
php5 netstat.php noprogress >index.htm
 
# For the control file nestat.ctl remove date+time and version
# and make error notices (in title="...") visible
sed -e '
   /^<p class="\(datetime\|version\)">/d
   /^<meta http-equiv="Refresh" /d
   /^<tr><td>/{
       s|title="\([^"][^"<>]*\)">Offline</td></tr>|>Offline: \1</td></tr>|
   }
   ' index.htm \
| lynx -dump -nolist -force_html -stdin \
> netstat.ctl
 
# If the file is different compared to the previous one mail it
diff -q netstat.ctl oldstatus.ctl >/dev/null \
|| mail -s "netstat as of $(date +%Y-%m-%d\ %H:%M\ %Z)" root \
< netstat.ctl

Discussion

See Network status for our users

1)
Technically, netstat.php uses PHP's fsockopen() to create an Internet or *nix domain socket connection.
2)
read should ;-)