kpacha

Creating your sdk for suricate

Oct 19th, 2014

This is the second article of the service discovering in PHP environments serie. The first one was about implementing a Curator Service Discovering REST Server. This will be about creating a simple sdk to provide a nice integration to the autodiscovering service to your clients.

The REST interface#

The rest interface is defined in the homepage of the suricate project.

TLDR? here goes the short version:

# Register the host 'ca2fff8e-d756-480c-b59e-8297ff88624b' in the cluster 'test'
$ curl -i -H "Accept: application/json" -H "Content-Type: application/json" -X PUT -d '{"name": "test", "id": "ca2fff8e-d756-480c-b59e-8297ff88624b", "address": "10.20.30.40", "port": 1234, "payload": "supu", "registrationTimeUTC": 1325129459728, "serviceType": "STATIC"}' http://localhost:8080/v1/service/test/ca2fff8e-d756-480c-b59e-8297ff88624b

# Get all registered services
$ curl -i http://localhost:8080/v1/service

# Get all nodes in 'test' service
$ curl -i http://localhost:8080/v1/service/test

# Get the node 'ca2fff8e-d756-480c-b59e-8297ff88624b' of the 'test' service
$ curl -i http://localhost:8080/v1/service/test/ca2fff8e-d756-480c-b59e-8297ff88624b


# Get the node 'ca2fff8e-d756-480c-b59e-8297ff88624b' of the 'test' service
$ curl -i -X DELETE http://localhost:8080/v1/service/test/ca2fff8e-d756-480c-b59e-8297ff88624b

As you must seen, the data structure is

ServiceInstance

{
   "name": "test",
   "id": "ca2fff8e-d756-480c-b59e-8297ff88624b",
   "address": "10.20.30.40",
   "port": 1234,
   "payload": "From Test",
   "registrationTimeUTC": 1325129459728,
   "serviceType": "STATIC"
}

ServiceInstances

[
    {
       "name": "test",
       "id": "ca2fff8e-d756-480c-b59e-8297ff88624b",
       "address": "10.20.30.40",
       "port": 1234,
       "payload": "From Test",
       "registrationTimeUTC": 1325129459728,
       "serviceType": "STATIC"
    },

    {
       "name": "foo",
       "id": "bd4fff8e-c234-480c-f6ee-8297ff813765",
       "address": "10.20.30.40",
       "sslPort": 1235,
       "payload": "foo-bar",
       "registrationTimeUTC": 1325129459728,
       "serviceType": "STATIC"
    }
]

ServiceNames

[
    {
        "name": "foo"
    },

    {
        "name": "bar"
    }
]

The REST client#

Once you are familiar with the REST interface, it's time to build the client. I did it in php, with great help of the Guzzle lib.

First of all, the package dependencies. I created a REST client and CLI interface, so there were my dependencies:

{
    ...
    "require": {
        "php": ">=5.3.3",
        "symfony/console": "~2.4",
        "guzzle/guzzle":"~3.7"
    },
    ...
}

The suricate client must expose the metods the REST interface encasulates, so it has to implement this 'interface':

abstract public function getAllNames();

abstract public function getAll($service);

abstract public function get($service, $id);

abstract public function putService($service, $id, $node);

abstract public function removeService($service, $id);

My implementation of this 'interface' is here.

Whith your implementation, you'll be able to interact with the REST service discovering server easily

$client = ... // instantiate your implementation

$success = $client->putService($serviceName, $nodeId, $node);
$serviceNames = $client->getAllNames();
$nodes = $client->getAll($serviceName);
$node = $client->get($serviceName, $nodeId);
$success = $client->removeService($serviceName, $nodeId);

The suricate-php-sdk also offers a set of commands to interact to de REST server through the CLI.

Coming soon: getting more from the sdk and integrating the service discovering with your local configuration

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