APC PDU Library

PHP library for reading data from APC PDU AP8XXX series via SNMP (v1 and v3) or SSH with Network Port Sharing support.

Requirements

• PHP 8.2+
• One of the following backends:
  • ext-snmp - PHP SNMP extension (for Native client)
  • net-snmp - System package (for Binary client)
  • freedsx/snmp - Composer package (for FreeDSx client)
  • ext-ssh2 - PHP SSH2 extension (for SSH client)

Installation

composer require sunfoxcz/apc-pdu

Usage

SNMPv1 Connection

use Sunfox\ApcPdu\ApcPduFactory;
use Sunfox\ApcPdu\DeviceMetric;
use Sunfox\ApcPdu\OutletMetric;

$pdu = ApcPduFactory::snmpV1('192.168.1.100', 'public');

SNMPv3 Connection

$pdu = ApcPduFactory::snmpV3(
    '192.168.1.100',
    'monitor',
    'AuthPassphrase',
    'PrivPassphrase'
);

Client Implementations

The library provides multiple SNMP client implementations with automatic discovery:

Method	Description	Dependencies
snmpV1() / snmpV3()	Auto-detects best available client	Any of the below
snmpV1Binary() / snmpV3Binary()	Uses the snmpget binary via shell	net-snmp package
snmpV1FreeDsx() / snmpV3FreeDsx()	Uses the FreeDSx SNMP library	freedsx/snmp composer package
snmpV1Native() / snmpV3Native()	Uses PHP's native SNMP functions	ext-snmp
ssh()	Uses SSH/CLI interface	ext-ssh2

Automatic Client Discovery

The snmpV1() and snmpV3() methods automatically detect and use the best available SNMP client in priority order:

1. Binary - Most efficient batch operations (net-snmp package)
2. FreeDSx - Efficient batch operations, pure PHP (freedsx/snmp)
3. Native - Fallback, slower batch operations (ext-snmp)

If no client is available, a NoSnmpClientAvailableException is thrown.

// Auto-detect best available client (recommended)
$pdu = ApcPduFactory::snmpV3($host, $user, $authPass, $privPass);

// Or explicitly choose a specific client:

// Binary - requires net-snmp package (apt install snmp)
$pdu = ApcPduFactory::snmpV3Binary($host, $user, $authPass, $privPass);

// FreeDSx - pure PHP, no extensions required (composer require freedsx/snmp)
$pdu = ApcPduFactory::snmpV3FreeDsx($host, $user, $authPass, $privPass);

// Native - requires ext-snmp PHP extension
$pdu = ApcPduFactory::snmpV3Native($host, $user, $authPass, $privPass);

// SSH - uses CLI commands over SSH (requires ext-ssh2)
$pdu = ApcPduFactory::ssh($host, $sshUser, $sshPass);

Performance Comparison

Benchmark results (SNMPv3, AP8653 PDU):

Operation	Native	Binary	FreeDSx	SSH
Single device metric	128 ms	69 ms	73 ms	905 ms
Device metrics (batch)	1.26 s	200 ms	215 ms	N/A*
Single outlet metric	62 ms	65 ms	233 ms	904 ms
Outlet metrics (batch)	1.09 s	213 ms	229 ms	N/A*
All 24 outlets	25.82 s	7.07 s	7.45 s	N/A*
Full PDU status	54.74 s	16.64 s	13.72 s	N/A*

*SSH uses an interactive shell which adds latency. It supports only a limited set of metrics (Power, Energy, ApparentPower, PowerFactor, Current, Name) and cannot retrieve full device/outlet status.

Recommendations:

• Native: Good for simple single-metric queries, requires ext-snmp
• Binary: Best batch performance, requires net-snmp system package
• FreeDSx: Best for full status dumps, pure PHP with no extension dependencies
• SSH: Alternative when SNMP is unavailable, limited metrics support

Run bin/benchmark to compare performance on your system. Use --ssh flag to include SSH in the comparison.

Device-Level Metrics

// Get individual metrics (PDU 1 is default)
$power = $pdu->getDevice(DeviceMetric::Power);           // Returns watts
$peak = $pdu->getDevice(DeviceMetric::PeakPower);        // Returns watts
$energy = $pdu->getDevice(DeviceMetric::Energy);         // Returns kWh
$name = $pdu->getDevice(DeviceMetric::Name);             // Returns string
$loadStatus = $pdu->getDevice(DeviceMetric::LoadStatus); // Returns int (1=Normal, 2=LowLoad, 3=NearOverload, 4=Overload)
$apparentPower = $pdu->getDevice(DeviceMetric::ApparentPower);  // Returns VA
$powerFactor = $pdu->getDevice(DeviceMetric::PowerFactor);      // Returns ratio (0.0-1.0)

// Get all device metrics at once as DTO
$device = $pdu->getDeviceStatus();
echo $device->powerW;           // Current power in watts
echo $device->peakPowerW;       // Peak power in watts
echo $device->energyKwh;        // Total energy in kWh
echo $device->name;             // Device name
echo $device->loadStatus->name; // LoadStatus enum (Normal, LowLoad, NearOverload, Overload)
echo $device->apparentPowerVa;  // Apparent power in VA
echo $device->powerFactor;      // Power factor (0.0-1.0)
echo $device->outletCount;      // Number of outlets
echo $device->phaseCount;       // Number of phases

Outlet-Level Metrics

// Get individual outlet metrics
$name = $pdu->getOutlet(1, 5, OutletMetric::Name);
$power = $pdu->getOutlet(1, 5, OutletMetric::Power);
$current = $pdu->getOutlet(1, 5, OutletMetric::Current);
$energy = $pdu->getOutlet(1, 5, OutletMetric::Energy);
$state = $pdu->getOutlet(1, 5, OutletMetric::State);  // 1=Off, 2=On

// Get all metrics for one outlet as DTO
$outlet = $pdu->getOutletStatus(1, 5);
echo $outlet->name;          // Outlet name
echo $outlet->index;         // Outlet index
echo $outlet->state->name;   // PowerState enum (Off, On)
echo $outlet->currentA;      // Current in amps
echo $outlet->powerW;        // Power in watts
echo $outlet->peakPowerW;    // Peak power in watts
echo $outlet->energyKwh;     // Energy in kWh
echo $outlet->outletType;    // Outlet type (e.g., "IEC C13")

// Get all outlets for a PDU
$outlets = $pdu->getAllOutlets(1);

Outlet Control (Write Operations)

use Sunfox\ApcPdu\OutletCommand;

// Get an outlet object for control operations
$outlet = $pdu->getOutlet(1, 5);  // PDU 1, Outlet 5

// Power control
$outlet->setState(OutletCommand::On);      // Turn on
$outlet->setState(OutletCommand::Off);     // Turn off
$outlet->setState(OutletCommand::Reboot);  // Reboot (off then on)

// Configuration
$outlet->setName('Web Server');
$outlet->setExternalLink('https://example.com/server1');

// Power thresholds (in Watts)
$outlet->setLowLoadThreshold(10);
$outlet->setNearOverloadThreshold(400);
$outlet->setOverloadThreshold(500);

Device Reset Operations

// Reset device-level counters
$pdu->resetDevicePeakPower(1);   // Reset peak power to current load
$pdu->resetDeviceEnergy(1);      // Reset energy meter to zero

// Reset all outlet counters
$pdu->resetOutletsPeakPower(1);  // Reset all outlets peak power
$pdu->resetOutletsEnergy(1);     // Reset all outlets energy meters

Complete Status

// Get complete status for one PDU
$pduInfo = $pdu->getPduInfo(1);
echo $pduInfo->pduIndex;
echo $pduInfo->device->powerW;
foreach ($pduInfo->outlets as $outlet) {
    echo $outlet->name . ': ' . $outlet->powerW . 'W';
}

// Get complete dump of all PDUs (stops when PDU not found)
$status = $pdu->getFullStatus();

Network Port Sharing (NPS)

When multiple PDUs are daisy-chained (up to 4 PDUs supported), specify the PDU index as the second parameter:

use Sunfox\ApcPdu\DeviceMetric;

// PDU 1 (Host) - default when no index specified
$hostPower = $pdu->getDevice(DeviceMetric::Power);
$hostPower = $pdu->getDevice(DeviceMetric::Power, 1);  // Explicit

// PDU 2 (Guest)
$guest1Power = $pdu->getDevice(DeviceMetric::Power, 2);

// PDU 3 and 4 (additional guests)
$guest2Power = $pdu->getDevice(DeviceMetric::Power, 3);
$guest3Power = $pdu->getDevice(DeviceMetric::Power, 4);

// Get all metrics for specific PDU
$device = $pdu->getDeviceStatus(2);  // All metrics for PDU 2

Testing Connection

if ($pdu->testConnection()) {
    echo "PDU is reachable";
}

Available Metrics

Device Metrics (DeviceMetric)

Metric	Unit	Description
ModuleIndex	-	Module index
PduIndex	-	PDU index
Name	string	Device name
LoadStatus	LoadStatus	Load status (Normal, LowLoad, NearOverload, Overload)
Power	W	Current power consumption
PeakPower	W	Peak power since last reset
PeakPowerTimestamp	datetime	When peak power occurred
PeakPowerStartTime	datetime	When peak power tracking started (last reset)
Energy	kWh	Total energy since last reset
EnergyStartTime	datetime	When energy tracking started (last reset)
ApparentPower	VA	Apparent power
PowerFactor	ratio	Power factor (0.0-1.0)
OutletCount	-	Number of outlets
PhaseCount	-	Number of phases
LowLoadThreshold	%	Low load warning threshold
NearOverloadThreshold	%	Near overload warning threshold
OverloadRestriction	-	Overload restriction setting

Outlet Metrics (OutletMetric)

Metric	Unit	Description
ModuleIndex	-	Module index
PduIndex	-	PDU index
Name	string	Outlet name/label
Index	int	Outlet index
State	PowerState	Power state (Off, On)
Current	A	Current draw
Power	W	Power consumption
PeakPower	W	Peak power
PeakPowerTimestamp	datetime	When peak power occurred
PeakPowerStartTime	datetime	When peak power tracking started (last reset)
Energy	kWh	Total energy
EnergyStartTime	datetime	When energy tracking started (last reset)*
OutletType	string	Outlet type (e.g., "IEC C13")
ExternalLink	string	External link URL

*Note: EnergyStartTime for outlets is shared across all outlets on a PDU (comes from device-level rPDU2DeviceStatusOutletsEnergyStartTime OID). When you reset an outlet's energy, all outlets share the same start time.

Enums

use Sunfox\ApcPdu\LoadStatus;
use Sunfox\ApcPdu\PowerState;
use Sunfox\ApcPdu\OutletCommand;

// LoadStatus values
LoadStatus::Normal;       // 1
LoadStatus::LowLoad;      // 2
LoadStatus::NearOverload; // 3
LoadStatus::Overload;     // 4

// PowerState values
PowerState::Off; // 1
PowerState::On;  // 2

// OutletCommand values (for write operations)
OutletCommand::On;     // 1
OutletCommand::Off;    // 2
OutletCommand::Reboot; // 3

Tested Devices

• APC AP8653 (Metered by Outlet with Switching)
• Rack PDU FW: 7.1.4
• APC OS: 7.1.2

Development

Running Tests with Docker

# Create .env file with your PDU credentials
cp .env.example .env
# Edit .env with your settings

# Run unit tests (default)
docker compose run --rm php

# Run integration tests (requires real PDU)
docker compose run --rm integration

# Run PHPStan analysis
docker compose run --rm phpstan

# Run PSR-12 coding style check
docker compose run --rm phpcs

# Auto-fix PSR-12 violations
docker compose run --rm phpcbf

# Run benchmark (requires real PDU)
docker compose run --rm php bin/benchmark --help

Without Docker

composer install
composer test

License

MIT License. See LICENSE for details.