HAProxyAPI

PHP API for HAProxy administration

This PHP API lets you programatically access HAProxy for both admin and read-only commands like enabling/disabling servers, and checking the status of servers. I can communicate via HAProxy over the builtin HTTP stats web page, using the built-in UNIX domain socket, or over TCP if, for example, you are proxying your domain socket to a TCP socket so you can access it remotely.

The HAProxy HTTP interface only supports Stats, EnableServer and DisableServer, so use of the domain or TCP socket is required for all other commands.

HAProxyAPI was written by Steve Kamerman and is distributed under the GNU GPLv3 license.

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Getting Started

Before you can use HAProxyAPI, you'll need to include the class loader. The API is PSR-0 compliant and has builtin Composer support. If you don't know what that means, you probably just want to use the included class loader, autoload.php:

<?php
require_once 'autoload.php';

Then, you'll need to create an HAProxy\Executor which is used to run all the commands.

Connecting to HAProxy via HTTP

Make sure you have the stats interface enabled in your HAProxy config. You will also need admin privileges if you want to enable or disable servers. Currently, authentication is required to use this method.

<?php
// Create a Executor for HTTP
$exec = new HAProxy\Executor('http://hostname:port/haproxy_stats_url', HAProxy\Executor::HTTP);
// Set your HAProxy stats page credentials
$exec->setCredentials('username', 'password');

Connecting to HAProxy via Socket

Socket communications requires the stats configuration option to be enabled, as well as the appropriate permission level to run the commands. Here's and example config for enabling the stats socket:

global
    stats    socket /tmp/haproxy-stats    user haproxy group haproxy mode 700 level admin

To use the UNIX domain socket interface for HAProxy, you pass its full filename to the constructor:

<?php
// Create a Executor for HTTP
$exec = new HAProxy\Executor('/tmp/haproxy-stats', HAProxy\Executor::SOCKET);

Connecting to HAProxy via TCP/IP

HAProxy does not ship with TCP/IP support, but it does support UNIX domain sockets. You can use something like socat or netcat/nc to make your domain socket accessible via TCP/IP. This example exposes the socket to the localhost on port 10010:

socat TCP-LISTEN:10010,bind=127.0.0.1,reuseaddr,fork,su=haproxy,range=127.0.0.0/8 UNIX-CLIENT:/tmp/haproxy-stats

If you can access the socket via TCP/IP, you can use HAProxyAPI to connect to it as well (think socat + ssh-port-forwarding = secure-remote-admin).

For this setup, you use the same socket setup as above, but you pass a hostname and port instead:

<?php
// Create a Executor for HTTP
$exec = new HAProxy\Executor('localhost:10010', HAProxy\Executor::SOCKET);

Getting Statistics

To get a statistics object, use HAProxy\Stats::get($exec):

<?php
// Connect
$exec = new HAProxy\Executor('localhost:10010', HAProxy\Executor::SOCKET);
// Get stats
$stats = HAProxy\Stats::get($exec);
// Show a tree of the backends, frontends and servers
echo $stats->dumpServiceTree();

That will output something like this:

+- foo-service
|  +- FRONTEND (OPEN)
|
+- foo-nodes
|  +- node01.foobar.com (UP)
|  +- node02.foobar.com (MAINT)
|  +- node03.foobar.com (UP)
|  +- node04.foobar.com (UP)
|  +- BACKEND (UP)
|
+- stats
|  +- FRONTEND (OPEN)
|  +- BACKEND (UP)

Using this information, you can get statistics about individual servers:

<?php
$server = $stats->getServiceStats('foo-nodes','node01.foobar.com');
echo "-------------------------------------\n";
echo "{$server->info->service_name}: {$server->health->status} ({$server->health->check_status} - {$server->health->check_duration}ms )\n";
echo "-------------------------------------\n";
echo $server->dump();
echo "-------------------------------------\n";

Output:

-------------------------------------
node01.foobar.com: UP (L7OK - 4ms )
-------------------------------------
Info Stats:
        proxy_name: foo-nodes
        service_name: node01.foobar.com
        weight: 1
        process_id: 1
        proxy_id: 2
        service_id: 1
        tracked:
        type: 2
Health Stats:
        status: UP
        active: 1
        backup: 0
        check_failed: 414
        up_down_transitions: 11
        status_change: 22700
        downtime: 7875
        throttle:
        selected_total: 1309606
        check_status: L7OK
        check_code: 200
        check_duration: 4
        check_fail_details: 0
Queue Stats:
        current: 0
        max: 0
        limit:
Session Stats:
        current: 0
        max: 26
        limit:
Bytes Stats:
        in: 697255098
        out: 598278314
Rate Stats:
        current: 0
        max: 49
        limit:
Denied Stats:
        requests:
        responses: 0
Error Stats:
        requests:
        responses: 0
        connections: 2
Warning Stats:
        retries: 151
        redispatches: 23
HttpResponseCode Stats:
        http_1xx: 0
        http_2xx: 1308874
        http_3xx: 0
        http_4xx: 537
        http_5xx: 0
-------------------------------------

Enabling/Disabling Servers

You can put servers into maintanence mode (aka disabled mode) and bring them back up using the HAProxy\Command\DisableServer and HAProxy\Command\EnableServer HAProxyAPI commands.

Both commands take a backend service name (ex: foo-nodes) and a server name (ex: node01.foobar.com).

To execute commands, you pass them to the HAProxy\Executor::execute($command) method:

<?php
// Create a Executor for HTTP
$exec = new HAProxy\Executor('http://hostname:port/haproxy_stats_url', HAProxy\Executor::HTTP);
// Set your HAProxy stats page credentials
$exec->setCredentials('username', 'password');

// Disable foo-nodes/node01.foobar.com in the load balancer
$exec->execute(new HAProxy\Command\DisableServer('foo-nodes', 'node01.foobar.com'));

// Show stats - you can see node01 is down
echo HAProxy\Stats::get($exec)->dumpServiceTree();
/*
+- foo-service
|  +- FRONTEND (OPEN)
|
+- foo-nodes
|  +- node01.foobar.com (MAINT)
|  +- node02.foobar.com (UP)
|  +- node03.foobar.com (UP)
|  +- node04.foobar.com (UP)
|  +- BACKEND (UP)
|
+- stats
|  +- FRONTEND (OPEN)
|  +- BACKEND (UP)
*/

// Enable foo-nodes/node01.foobar.com
$exec->execute(new HAProxy\Command\EnableServer('foo-nodes', 'node01.foobar.com'));

// Show stats - you can see node01 is coming up
echo HAProxy\Stats::get($exec)->dumpServiceTree();
/*
+- foo-service
|  +- FRONTEND (OPEN)
|
+- foo-nodes
|  +- node01.foobar.com (UP 1/3)
|  +- node02.foobar.com (UP)
|  +- node03.foobar.com (UP)
|  +- node04.foobar.com (UP)
|  +- BACKEND (UP)
|
+- stats
|  +- FRONTEND (OPEN)
|  +- BACKEND (UP)
*/