Merge pull request #42 from Clariteia/issue-41-adapt-to-new-discovery

#41 (Adapt to new `discovery`)

Author: Sergio García Prado

minos/api_gateway/rest/__init__.py

@@ -7,15 +7,9 @@
 """
 __version__ = "0.0.2"
 
-from .coordinator import (
-    MicroserviceCallCoordinator,
-)
 from .launchers import (
     EntrypointLauncher,
 )
 from .service import (
     ApiGatewayRestService,
 )
-from .utils import (
-    DefaultController,
-)

minos/api_gateway/rest/cli.py

@@ -41,7 +41,9 @@ def start(
         typer.echo(f"Error loading config: {exc!r}")
         raise typer.Exit(code=1)
 
-    services = (ApiGatewayRestService(config=config),)
+    services = (
+        ApiGatewayRestService(address=config.rest.connection.host, port=config.rest.connection.port, config=config),
+    )
     try:
         EntrypointLauncher(config=config, services=services).launch()
     except Exception as exc:

minos/api_gateway/rest/coordinator.py

@@ -0,0 +1,91 @@
+"""minos.api_gateway.rest.handler module."""
+
+import logging
+from typing import (
+    Any,
+)
+
+from aiohttp import (
+    ClientConnectorError,
+    ClientResponse,
+    ClientSession,
+    web,
+)
+from yarl import (
+    URL,
+)
+
+logger = logging.getLogger(__name__)
+
+
+async def orchestrate(request: web.Request) -> web.Response:
+    """ Orchestrate discovery and microservice call """
+    discovery_host = request.app["config"].discovery.connection.host
+    discovery_port = request.app["config"].discovery.connection.port
+
+    verb = request.method
+    url = f"/{request.match_info['endpoint']}"
+
+    discovery_data = await discover(discovery_host, int(discovery_port), "/microservices", verb, url)
+
+    microservice_response = await call(**discovery_data, original_req=request)
+    return microservice_response
+
+
+async def discover(host: str, port: int, path: str, verb: str, endpoint: str) -> dict[str, Any]:
+    """Call discovery service and get microservice connection data.
+
+    :param host: Discovery host name.
+    :param port: Discovery port.
+    :param path: Discovery path.
+    :param verb: Endpoint Verb.
+    :param endpoint: Endpoint url.
+    :return: The response of the discovery.
+    """
+
+    url = URL.build(scheme="http", host=host, port=port, path=path, query={"verb": verb, "path": endpoint})
+    try:
+        async with ClientSession() as session:
+            async with session.get(url=url) as response:
+                if not response.ok:
+                    raise web.HTTPBadGateway(text="The discovery response is not okay.")
+                data = await response.json()
+    except ClientConnectorError:
+        raise web.HTTPGatewayTimeout(text="The discovery is not available.")
+
+    data["port"] = int(data["port"])
+
+    return data
+
+
+# noinspection PyUnusedLocal
+async def call(address: str, port: int, original_req: web.Request, **kwargs) -> web.Response:
+    """Call microservice (redirect the original call)
+
+    :param address: The ip of the microservices.
+    :param port: The port of the microservice.
+    :param original_req: The original request.
+    :param kwargs: Additional named arguments.
+    :return: The web response to be retrieved to the client.
+    """
+
+    headers = original_req.headers
+    url = original_req.url.with_scheme("http").with_host(address).with_port(port)
+    method = original_req.method
+    content = await original_req.text()
+
+    logger.info(f"Redirecting {method!r} request to {url!r}...")
+
+    try:
+        async with ClientSession(headers=headers) as session:
+            async with session.request(method=method, url=url, data=content) as response:
+                return await _clone_response(response)
+    except ClientConnectorError:
+        raise web.HTTPServiceUnavailable(text="The requested endpoint is not available.")
+
+
+# noinspection PyMethodMayBeStatic
+async def _clone_response(response: ClientResponse) -> web.Response:
+    return web.Response(
+        body=await response.read(), status=response.status, reason=response.reason, headers=response.headers,
+    )

minos/api_gateway/rest/handler.py

@@ -1,29 +1,33 @@
-# Copyright (C) 2020 Clariteia SL
-#
-# This file is part of minos framework.
-#
-# Minos framework can not be copied and/or distributed without the express
-# permission of Clariteia SL.
+"""minos.api_gateway.rest.service module."""
 
-import typing as t
+import logging
 
 from aiohttp import (
     web,
 )
+from aiomisc.service.aiohttp import (
+    AIOHTTPService,
+)
 
 from minos.api_gateway.common import (
     MinosConfig,
-    RESTService,
 )
+from minos.api_gateway.rest import (
+    handler,
+)
+
+logger = logging.getLogger(__name__)
+
+
+class ApiGatewayRestService(AIOHTTPService):
+    def __init__(self, address: str, port: int, config: MinosConfig):
+        self.config = config
+        super().__init__(address, port)
+
+    async def create_application(self) -> web.Application:
+        app = web.Application()
+        app["config"] = self.config
 
+        app.router.add_route("*", "/{endpoint:.*}", handler.orchestrate)
 
-class ApiGatewayRestService(RESTService):
-    def __init__(self, config: MinosConfig, app: web.Application = web.Application(), **kwds: t.Any):
-        super().__init__(
-            address=config.rest.connection.host,
-            port=config.rest.connection.port,
-            endpoints=config.rest.endpoints,
-            config=config,
-            app=app,
-            **kwds
-        )
+        return app