Consul PHP SDK

Consul PHP SDK is a thin wrapper around the Consul HTTP API.

Compatibility

See previous version of README.md to find some version compatible with older version of symfony/http-client or guzzle

Installation

This library can be installed with composer:

composer require friendsofphp/consul-php-sdk

Supported services

• agent
• catalog
• health
• kv
• session
• txn

Usage

Instantiate a services, and start using it:

$kv = new Consul\Services\KV();

$kv->put('test/foo/bar', 'bazinga');
$kv->get('test/foo/bar', ['raw' => true]);
$kv->delete('test/foo/bar');

A service exposes few methods mapped from the consul API:

All services methods follow the same convention:

$response = $service->method($mandatoryArgument, $someOptions);

• All API mandatory arguments are placed as first;
• All API optional arguments are directly mapped from $someOptions;
• All methods return a Consul\ConsulResponse;
• If the API responds with a 4xx response, a Consul\Exception\ClientException is thrown;
• If the API responds with a 5xx response, a Consul\Exception\ServeException is thrown.

Cookbook

How to acquire an exclusive lock?

$session = new Consul\Services\Session();

$sessionId = $session->create()->json()['ID'];

// Lock a key / value with the current session
$lockAcquired = $kv->put('tests/session/a-lock', 'a value', ['acquire' => $sessionId])->json();

if (false === $lockAcquired) {
    $session->destroy($sessionId);

    echo "The lock is already acquire by another node.\n";
    exit(1);
}

echo "Do you jobs here....";
sleep(5);
echo "End\n";

$kv->delete('tests/session/a-lock');
$session->destroy($sessionId);

How to use MultiLockHandler?

$resources = ['resource1', 'resource2'];

$multiLockHandler = new MultiLockHandler($resources, 60, new Session(), new KV(), 'my/lock/');

if ($multiLockHandler->lock()) {
    try {
        echo "Do you jobs here....";
    } finally {
        $multiLockHandler->release();    
    }
}

How to use MultiSemaphore?

$resources = [
    new Resource('resource1', 2, 7),
    new Resource('resource2', 3, 6),
    new Resource('resource3', 1, 1),
];

$semaphore = new MultiSemaphore($resources, 60, new Session(), new KV(), 'my/semaphore');

if ($semaphore->acquire()) {
    try {
        echo "Do you jobs here....";
    } finally {
        $semaphore->release();    
    }
}

Some utilities

• Consul\Helper\LockHandler: Simple class that implement a distributed lock
• Consul\Helper\MultiLockHandler: Simple class that implements a distributed lock for many resources
• Consul\Helper\MultiSemaphore: Simple class that implements a distributed semaphore for many resources

Run the test suite

You need a consul agent running on localhost:8500.

But you ca override this address:

export CONSUL_HTTP_ADDR=172.17.0.2:8500

If you don't want to install Consul locally you can use a docker container:

docker run -d --name=dev-consul -e CONSUL_BIND_INTERFACE=eth0 consul

Then, run the test suite

vendor/bin/simple-phpunit