Monitor TCP/IP Port Consumption via PHP - php

Question

So I'm running PHP on an Azure Web App. Recently, I ran into an issue with my server going into TCP/IP Port Exhaustion, because I was not using persistent connections to my Redis Cache. I don't believe the issue should come up again, but since I don't have any metrics available for this (and since I can't just remote into an Azure Web App), I was wondering if there's any functions in PHP that would allow me to see information about all the TCP ports currently in use by the server, so I can log that for diagnostics.
Does anyone have any ideas on how this can be accomplished? My initial thinking is that I would need to use shell_exec.

Answer 1

Unfortunately, I can't get this to work on Azure Web App, however I think this would work in other scenarios, where you are running your own server.
class netstat {
public $PortsInUse = 0;
public $AvailablePorts = 0;
public $TotalPorts = 0;
public $Ports = array();
public function __construct () {
$p = popen('netsh int ipv4 show dynamicport tcp', 'r');
$this->TotalPorts = rtrim(trim(explode("Number of Ports : ", stream_get_contents($p))[1]));
pclose($p);
$netstat = popen('netstat -no', 'r');
$log = stream_get_contents($netstat);
pclose($netstat);
$this->Ports = array_slice(explode("\n", $log), 4);
array_pop($this->Ports);
foreach($this->Ports as &$port) {
$port = explode(" ", $port);
foreach($port as $k => $p) {
if (empty($p))
unset($port[$k]);
}
$port = array_values($port);
$port = (object)array(
"LocalAddress" => $port[0],
"ForeignAddress" => $port[1],
"Status" => $port[2],
"ProcessId" => $port[3]
);
}
$this->PortsInUse = count($this->Ports);
$this->AvailablePorts = $this->TotalPorts - count($this->Ports);
}
}
The above object will be able to display the current number of TCP ports in use, and the total number of dynamic ports available for TCP on that machine. It also contains a "Ports" array, which contains information about each port in use, such as their local and foreign address, status and PID (process id).