Add litestar integrations docs

Author: draincoder

docs/integrations/index.rst

@@ -1,5 +1,6 @@
 .. _FastAPI: https://fastapi.tiangolo.com
 .. _Starlette: https://www.starlette.io
+.. _Litestar: https://litestar.dev
 .. _real_world: https://github.com/draincoder/asgi-monitor/tree/master/examples/real_world
 
 .. _integrations:
@@ -11,6 +12,7 @@ Integration with the following frameworks is **now** implemented:
 
 * FastAPI_
 * Starlette_
+* Litestar_
 
 But other integrations are planned in the near future, and you can also implement your own through **PR**.
 
@@ -65,3 +67,78 @@ These frameworks have the **same** integration api, so here I will show you how
 For **Starlette**, simply replace ``fastapi`` with ``starlette`` in the **integration** import line.
 
 Check out the real_world_ example to figure out how it works.
+
+
+Litestar
+====================
+
+.. important::
+
+   The API is incompatible with FastAPI and Starlette, the rules for determining the path are different, the type of error is not detected.
+
+Litestar out of the box has many add-ons:
+
+1. **Prometheus** support
+2. **OpenTelemetry** support
+3. **Structlog** plugin
+
+But they all have disadvantages, for example, you can use only **global metrics** with a **global registry**, metrics are not compatible with the trace context, logs also do not support the trace context.
+
+So **asgi-monitor** is rushing to the rescue.
+
+.. code-block:: python
+   :caption: Configuring monitoring for the Litestar
+
+   import logging
+
+   from asgi_monitor.integrations.litestar import (
+       MetricsConfig,
+       TracingConfig,
+       add_metrics_endpoint,
+       build_metrics_middleware,
+       build_tracing_middleware,
+   )
+   from asgi_monitor.logging import configure_logging
+   from asgi_monitor.logging.uvicorn import build_uvicorn_log_config
+   from litestar import Litestar
+   from opentelemetry import trace
+   from opentelemetry.sdk.resources import Resource
+   from opentelemetry.sdk.trace import TracerProvider
+   import uvicorn
+
+   logger = logging.getLogger(__name__)
+
+
+   def create_app() -> Litestar:
+       configure_logging(level=logging.INFO, json_format=True, include_trace=False)
+
+       resource = Resource.create(
+           attributes={
+               "service.name": "litestar",
+           },
+       )
+       tracer = TracerProvider(resource=resource)
+       trace.set_tracer_provider(tracer)
+
+       trace_config = TracingConfig(tracer_provider=tracer)
+       metrics_config = MetricsConfig(app_name="litestar", include_trace_exemplar=True)
+
+       middlewares = [build_tracing_middleware(trace_config), build_metrics_middleware(metrics_config)]
+
+       app = Litestar([index], middleware=middlewares, logging_config=None)
+
+       add_metrics_endpoint(app, metrics_config.registry)
+
+       return app
+
+
+   if __name__ == "__main__":
+       log_config = build_uvicorn_log_config(level=logging.INFO, json_format=True, include_trace=True)
+       uvicorn.run(create_app(), host="127.0.0.1", port=8000, log_config=log_config)
+
+If you want to use **StructlogPlugin** from ``litestar.plugins.structlog`` together with tracing, you can embed a processor in the structlog processor chain to export the trace context to the log.
+
+.. code-block:: python
+   :caption: Import processor for extract trace meta
+
+   from asgi_monitor.logging.trace_processor import extract_opentelemetry_trace_meta

docs/monitoring/metrics.rst

@@ -50,8 +50,6 @@ The ``BaseMetricsConfig`` class is used to configure metrics, and it accepts the
 
 4. ``include_trace_exemplar`` (**bool**) - Whether to include trace exemplars in the metrics. Default is ``False``. This is only necessary if **tracing** is configured and metrics are collected in the ``OpenMetrics`` format.
 
-5. ``include_metrics_endpoint`` (**bool**) Whether to include a **/metrics** endpoint. Default is ``True``. Collecting metrics in ``text/plain`` format.
-
 You can also set up a **global** ``prometheus_client.REGISTRY`` in ``MetricsConfig`` to support your **global** metrics,
 but it is better to use your own **non-global** registry or leave the **default** registry.
 
@@ -71,7 +69,7 @@ but it is better to use your own **non-global** registry or leave the **default*
 Exporting
 ~~~~~~~~~~~~~~~~~~
 
-If you are using integration with the web framework, you can add metric exports via the config by setting ``include_metrics_endpoint`` to ``True``. In this case, the metrics will be exported via the **/metrics** endpoint in ``text/plain`` format.
+If you are using integration with the web framework, you can add metric exports via the config by setting ``include_metrics_endpoint`` to ``True`` or by explicitly calling ``add_metrics_endpoint``. In this case, the metrics will be exported via the **/metrics** endpoint in ``text/plain`` format.
 
 In case you need to **customize the endpoint**, add **protection**, use the **OpenMetrics** format, or just use **another method for delivering** metrics, then you should use the built-in ``get_latest_metrics`` function.