Merge branch '4.4'

* 4.4:
  [Monolog] Added documentation about ElasticsearchLogstashHandler

Author: javiereguiluz

logging.rst

@@ -366,6 +366,7 @@ Learn more
     logging/channels_handlers
     logging/formatter
     logging/processors
+    logging/handlers
     logging/monolog_exclude_http_codes
     logging/monolog_console
 

logging/handlers.rst

@@ -0,0 +1,107 @@
+Handlers
+========
+
+ElasticsearchLogstashHandler
+----------------------------
+
+.. versionadded:: 4.4
+
+    The ``ElasticsearchLogstashHandler`` was introduced in Symfony 4.4.
+
+This handler deals directly with the HTTP interface of Elasticsearch. This means
+it will slow down your application if Elasticsearch takes times to answer. Even
+if all HTTP calls are done asynchronously.
+
+In a development environment, it's fine to keep the default configuration: for
+each log, an HTTP request will be made to push the log to Elasticsearch.
+
+In a production environment, it's highly recommended to wrap this handler in a
+handler with buffering capabilities (like the ``FingersCrossedHandler`` or
+``BufferHandler``) in order to call Elasticsearch only once with a bulk push. For
+even better performance and fault tolerance, a proper `ELK stack`_ is recommended.
+
+To use it, declare it as a service:
+
+.. configuration-block::
+
+    .. code-block:: yaml
+
+        # config/services.yaml
+        services:
+            Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler: ~
+
+    .. code-block:: xml
+
+        <!-- config/services.xml -->
+        <?xml version="1.0" encoding="UTF-8" ?>
+        <container xmlns="http://symfony.com/schema/dic/services"
+            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+            xmlns:monolog="http://symfony.com/schema/dic/monolog"
+            xsi:schemaLocation="http://symfony.com/schema/dic/services
+                https://symfony.com/schema/dic/services/services-1.0.xsd
+                http://symfony.com/schema/dic/monolog
+                https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
+
+            <services>
+                <service id="Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler"/>
+            </services>
+        </container>
+
+    .. code-block:: php
+
+        // config/services.php
+        use App\Logger\SessionRequestProcessor;
+        use Monolog\Formatter\LineFormatter;
+        use Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler;
+
+        $container->register(ElasticsearchLogstashHandler::class);
+
+Then reference it in the Monolog configuration:
+
+.. configuration-block::
+
+    .. code-block:: yaml
+
+        # config/packages/prod/monolog.yaml
+        monolog:
+            handlers:
+                es:
+                    type: service
+                    id: Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler
+
+    .. code-block:: xml
+
+        <!-- config/packages/prod/monolog.xml -->
+        <?xml version="1.0" encoding="UTF-8" ?>
+        <container xmlns="http://symfony.com/schema/dic/services"
+            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+            xmlns:monolog="http://symfony.com/schema/dic/monolog"
+            xsi:schemaLocation="http://symfony.com/schema/dic/services
+                https://symfony.com/schema/dic/services/services-1.0.xsd
+                http://symfony.com/schema/dic/monolog
+                https://symfony.com/schema/dic/monolog/monolog-1.0.xsd">
+
+            <monolog:config>
+                <monolog:handler
+                    name="es"
+                    type="service"
+                    id="Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler"
+                />
+            </monolog:config>
+        </container>
+
+    .. code-block:: php
+
+        // config/packages/prod/monolog.php
+        use Symfony\Bridge\Monolog\Handler\ElasticsearchLogstashHandler;
+
+        $container->loadFromExtension('monolog', [
+            'handlers' => [
+                'es' => [
+                    'type' => 'service',
+                    'id' => ElasticsearchLogstashHandler::class,
+                ],
+            ],
+        ]);
+
+.. _`ELK stack`: https://www.elastic.co/what-is/elk-stack