Merge pull request #601 from SakuraSound/master

Detailed example with logging, database access, environment variables, and basic middleware

examples/detailed_example.py

@@ -0,0 +1,136 @@
+# This demo requires aioredis and environmental variables established in ENV_VARS
+import json
+import logging
+import os
+
+from datetime import datetime
+
+import aioredis
+
+import sanic
+from sanic import Sanic
+
+
+ENV_VARS = ["REDIS_HOST", "REDIS_PORT",
+            "REDIS_MINPOOL", "REDIS_MAXPOOL",
+            "REDIS_PASS", "APP_LOGFILE"]
+
+app = Sanic(name=__name__)
+
+logger = None
+
+
+@app.middleware("request")
+async def log_uri(request):
+    # Simple middleware to log the URI endpoint that was called
+    logger.info("URI called: {0}".format(request.url))
+
+
+@app.listener('before_server_start')
+async def before_server_start(app, loop):
+    logger.info("Starting redis pool")
+    app.redis_pool = await aioredis.create_pool(
+        (app.config.REDIS_HOST, int(app.config.REDIS_PORT)),
+        minsize=int(app.config.REDIS_MINPOOL),
+        maxsize=int(app.config.REDIS_MAXPOOL),
+        password=app.config.REDIS_PASS)
+
+
+@app.listener('after_server_stop')
+async def after_server_stop(app, loop):
+    logger.info("Closing redis pool")
+    app.redis_pool.close()
+    await app.redis_pool.wait_closed()
+
+
+@app.middleware("request")
+async def attach_db_connectors(request):
+    # Just put the db objects in the request for easier access
+    logger.info("Passing redis pool to request object")
+    request["redis"] = request.app.redis_pool
+
+
+@app.route("/state/<user_id>", methods=["GET"])
+async def access_state(request, user_id):
+    try:
+        # Check to see if the value is in cache, if so lets return that
+        with await request["redis"] as redis_conn:
+            state = await redis_conn.get(user_id, encoding="utf-8")
+            if state:
+                return sanic.response.json({"msg": "Success",
+                                            "status": 200,
+                                            "success": True,
+                                            "data": json.loads(state),
+                                            "finished_at": datetime.now().isoformat()})
+        # Then state object is not in redis
+        logger.critical("Unable to find user_data in cache.")
+        return sanic.response.HTTPResponse({"msg": "User state not found",
+                                            "success": False,
+                                            "status": 404,
+                                            "finished_at": datetime.now().isoformat()}, status=404)
+    except aioredis.ProtocolError:
+        logger.critical("Unable to connect to state cache")
+        return sanic.response.HTTPResponse({"msg": "Internal Server Error",
+                                            "status": 500,
+                                            "success": False,
+                                            "finished_at": datetime.now().isoformat()}, status=500)
+
+
+@app.route("/state/<user_id>/push", methods=["POST"])
+async def set_state(request, user_id):
+    try:
+        # Pull a connection from the pool
+        with await request["redis"] as redis_conn:
+            # Set the value in cache to your new value
+            await redis_conn.set(user_id, json.dumps(request.json), expire=1800)
+            logger.info("Successfully pushed state to cache")
+            return sanic.response.HTTPResponse({"msg": "Successfully pushed state to cache",
+                                                "success": True,
+                                                "status": 200,
+                                                "finished_at": datetime.now().isoformat()})
+    except aioredis.ProtocolError:
+        logger.critical("Unable to connect to state cache")
+        return sanic.response.HTTPResponse({"msg": "Internal Server Error",
+                                            "status": 500,
+                                            "success": False,
+                                            "finished_at": datetime.now().isoformat()}, status=500)
+
+
+def configure():
+    # Setup environment variables
+    env_vars = [os.environ.get(v, None) for v in ENV_VARS]
+    if not all(env_vars):
+        # Send back environment variables that were not set
+        return False, ", ".join([ENV_VARS[i] for i, flag in env_vars if not flag])
+    else:
+        # Add all the env vars to our app config
+        app.config.update({k: v for k, v in zip(ENV_VARS, env_vars)})
+        setup_logging()
+    return True, None
+
+
+def setup_logging():
+    logging_format = "[%(asctime)s] %(process)d-%(levelname)s "
+    logging_format += "%(module)s::%(funcName)s():l%(lineno)d: "
+    logging_format += "%(message)s"
+
+    logging.basicConfig(
+        filename=app.config.APP_LOGFILE,
+        format=logging_format,
+        level=logging.DEBUG)
+
+
+def main(result, missing):
+    if result:
+        try:
+            app.run(host="0.0.0.0", port=8080, debug=True)
+        except:
+            logging.critical("User killed server. Closing")
+    else:
+        logging.critical("Unable to start. Missing environment variables [{0}]".format(missing))
+
+
+if __name__ == "__main__":
+    result, missing = configure()
+    logger = logging.getLogger()
+    main(result, missing)