ActivityPub Server - Usage

Server features are still a WIP.

Usage

use ActivityPhp\Server;

// Create a server instance
$server = new Server();

It’s a very minimalistic example of use. With this configuration, an instance can only request for public activities and can’t receive some data.

As you could imagine, a server instance, to be fully-functional, must accept some parameters.

Server parameters

A server instance can receive an array of configurations as first parameter.

use ActivityPhp\Server;

// Create a server instance with parameters
$server = new Server([
    'logger'     => [],
    'instance'   => [],
    'cache'      => [],
    'http'       => [],
    'dialects'   => [],
    'ontologies' => [],
]);

Each array defines a scope of configuration.


Logger parameters

Sometimes, for testing purpose, it may be suitable to block log output.

driver

use ActivityPhp\Server;

// Create a server instance with no log output
$server = new Server([
    'logger'   => [
        'driver' => '\Psr\Log\NullLogger'
    ],
]);

If you have specific needs (Storing logs into a database, for instance), you may pass a custom logger driver. As it implements Psr\Log\LoggerInterface, you may pass any custom logger.

By default, the driver is Monolog\Logger.

stream

The default output for logging message is php://stdout. You can pass a filename where logs will be put.

use ActivityPhp\Server;

// Put logs into a specific file
$server = new Server([
    'logger'   => [
        'stream' => '/var/log/activitypub/server.log'
    ],
]);

channel

The default channel is global. in order to customize, you can pass a channel parameter.

use ActivityPhp\Server;

// Put logs with a specific channel
$server = new Server([
    'logger'   => [
        'channel' => 'ap_channel'
    ],
]);

Instance parameters

host

The default hostname is localhost. If you want to be reachable from a network you may pass a custom hostname.

use ActivityPhp\Server;

$server = new Server([
    'instance'   => [
        'host' => 'activitypub.example.org'
    ],
]);

port

The default port is 443. If you want to customize it, you may pass a port parameter.

use ActivityPhp\Server;

$server = new Server([
    'instance'   => [
        'port' => 8000
    ],
]);

Note: this does not seem to be supported by all ActivityPub servers of the federation.

types

This option tells the instance which behaviour when an unknown property or an undefined type is encountered.

All federations (mastodon, peertube, pixelfed, etc…) are implementing non standard activity streams properties and types.

By default, an instance is configured in strict mode. When a non- standard type is encountered, if it’s not defined as a dialect, it throws an exception.

It can be blocking if you’re working with many kinds of federations.

So, you may configure your instance with a less strict requirement in two ways:

use ActivityPhp\Server;

$server = new Server([
    'instance'   => [
        'types' => 'include'
    ],
]);

debug

For testing purpose, you may use HTTP scheme instead of HTTPS. The debug parameter is made for that.

use ActivityPhp\Server;

$server = new Server([
    'instance'   => [
        'debug' => true
    ],
]);

For security purpose, the default value is false.


HTTP parameters

timeout

The default timeout for HTTP requests is 10s..

use ActivityPhp\Server;

// Increase HTTP request timeout to 20 seconds
$server = new Server([
    'http'   => [
        'timeout' => '20'
    ],
]);

agent

When talking to other federated servers, an instance uses the default user agent ActivityPhp/x.y.z (+https://{host}).

It can be customized with agent parameter.

use ActivityPhp\Server;

$server = new Server([
    'http'   => [
        'agent' => 'MyCustomUserAgent'
    ],
]);

Cache parameters

type

The default type of cache is filesystem. Cache is actived by default.

enabled

You can disable caching objects with enabled parameter.

use ActivityPhp\Server;

$server = new Server([
    'cache'   => [
        'enabled' => false
    ],
]);

stream

By default, it stores cache files in the common working directory (See PHP getcwd() manual).

You can customize where cache files are stored with the stream parameter.

use ActivityPhp\Server;

$server = new Server([
    'cache'   => [
        'stream' => '/mycustom/directory'
    ],
]);

ttl

The Time To Live (TTL) of an item is the amount of time in seconds between when that item is stored and it is considered stale.

The default value is 3600.

use ActivityPhp\Server;

$server = new Server([
    'cache'   => [
        'ttl' => 60 // Set to 60 seconds
    ],
]);

pool

ActivtyPhp comes with a default cache driver \Symfony\Component\Cache\Adapter\FilesystemAdapter.

There are 2 ways to override this driver with pool parameter.

You can pass a class name that will be automatically instanciated.

use ActivityPhp\Server;

$server = new Server([
    'cache'   => [
        'pool' => 'Symfony\Component\Cache\Adapter\ArrayAdapter'
    ],
]);

If you need a cache pool with custom configuration, you can pass an instanciated pool.

use ActivityPhp\Server;
use Symfony\Component\Cache\Adapter\ArrayAdapter;

$server = new Server([
    'cache'   => [
        'pool' => new ArrayAdapter()
    ],
]);

The given pool must implement Psr\Cache\CacheItemPoolInterface.

Note

All Symfony cache adapters are supplied as dependencies.


Dialects parameters

Dialect parameter has a special role.

It defines and load ActivityPub types and properties which are not defined in the standard protocol.

type

This parameter is a 3-levels array containing:

DialectName => Types => Properties

example

In this example, we define 2 dialects with 1 type for each.

The first type extends ActivityPub Person type with an uuid property. The second type creates a new type HashTag with 2 properties, uuid and name.

use ActivityPhp\Server;

$dialect1 = [
    'Person' => ['uuid'],
];

$dialect2 = [
    'HashTag' => ['uuid', 'name'],
];

$server = new Server([
    'dialects'   => [
        'dialect1' => $dialect1,
        'dialect2' => $dialect2,
    ],
]);

After this loading, the new types and properties are usable.

use ActivityPhp\Type;

$hashtag = Type::create([
    'type' => 'HashTag',
    'uuid' => 42,
    'name' => 'myTag'
];

$person  = Type::create([
    'type' => 'Person',
    'uuid' => 42
];

More about dialects management

An example of Peertube’s dialect implementation



Ontologies parameters

Ontology parameter has a special role.

It defines and load ActivityPub types and properties which are not defined in the standard protocol but that are commonly used by Federated applications. It permits that your application will be compatible with other federations.

type

This parameter is a 1 or 2-levels array containing:

OntologyName

or

OntologyName => CustomOntologyClassName

examples

In this example, we load Peertube’s ontology.

It’s a packaged ontology.

$server = new Server([
    'ontologies'   => [
        'peertube'
    ],
]);

After this loading, the new types and properties are usable.

In this second example, we load all predefined (packaged) ontologies.

$server = new Server([
    'ontologies'   => [
        '*'
    ],
]);

You can create and define your custom ones and load them.

$server = new Server([
    'ontologies'   => [
        'my-ontology' => MyClass::class
    ],
]);

For more informations about creating your custom ontology, see the dedicated manual ontologies management manual

Obviously, you can load several ontologies.

$server = new Server([
    'ontologies'   => [
        'peertube',
        'my-ontology' => MyClass::class
    ],
]);

This feature needs you. Contributions are very welcome.

More about ontologies management

An example of Peertube’s ontology implementation


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