Add ddog logger.

Author: toddbirchard

config.py

@@ -13,6 +13,7 @@ class Config:
 
     # General Config
     ENVIRONMENT = environ.get("ENVIRONMENT")
+    APP_NAME = "flask_sqlalchemy_tutorial"
 
     # Flask Config
     FLASK_APP = "wsgi.py"
@@ -23,3 +24,6 @@ class Config:
     SQLALCHEMY_DATABASE_URI = environ.get("SQLALCHEMY_DATABASE_URI")
     SQLALCHEMY_ECHO = False
     SQLALCHEMY_TRACK_MODIFICATIONS = False
+
+
+settings = Config

gunicorn.conf.py

@@ -24,9 +24,9 @@
     bind = ["127.0.0.1:8000"]
 elif ENVIRONMENT == "production":
     daemon = True
-    accesslog = "/var/log/flasksession/access.log"
-    errorlog = "/var/log/flasksession/error.log"
+    accesslog = "/var/log/flasksqlalchemy/access.log"
+    errorlog = "/var/log/flasksqlalchemy/error.log"
     loglevel = "trace"
-    dogstatsd_tags = "env:prod,service:flasksession,language:python"
+    dogstatsd_tags = "env:prod,service:flasksqlalchemy,language:python"
 else:
     raise ValueError(f"Unknown environment provided: `{ENVIRONMENT}`. Must be `development` or `production`.")

logger.py

@@ -0,0 +1,114 @@
+"""Custom logger."""
+
+import json
+from os import path
+from sys import stdout
+
+from loguru import logger
+
+from config import settings
+
+
+def json_formatter(record: dict) -> str:
+    """
+    Pass raw log to be serialized.
+
+    :param dict record: Dictionary containing logged message with metadata.
+
+    :returns: str
+    """
+
+    def serialize(log: dict) -> str:
+        """
+        Parse log message into Datadog JSON format.
+
+        :param dict log: Dictionary containing logged message with metadata.
+
+        :returns: str
+        """
+        subset = {
+            "time": log["time"].strftime("%m/%d/%Y, %H:%M:%S"),
+            "message": log["message"],
+            "level": log["level"].name,
+            "function": log.get("function"),
+            "module": log.get("name"),
+        }
+        if log.get("exception", None):
+            subset.update({"exception": log["exception"]})
+        return json.dumps(subset)
+
+    record["extra"]["serialized"] = serialize(record)
+    return "{extra[serialized]},\n"
+
+
+def log_formatter(record: dict) -> str:
+    """
+    Formatter for .log records
+
+    :param dict record: Key/value object containing log message & metadata.
+
+    :returns: str
+    """
+    if record["level"].name == "TRACE":
+        return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> | <fg #d2eaff>{level}</fg #d2eaff>: <light-white>{message}</light-white>\n"
+    if record["level"].name == "INFO":
+        return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> | <fg #98bedf>{level}</fg #98bedf>: <light-white>{message}</light-white>\n"
+    if record["level"].name == "WARNING":
+        return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> |  <fg #b09057>{level}</fg #b09057>: <light-white>{message}</light-white>\n"
+    if record["level"].name == "SUCCESS":
+        return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> | <fg #6dac77>{level}</fg #6dac77>: <light-white>{message}</light-white>\n"
+    if record["level"].name == "ERROR":
+        return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> | <fg #a35252>{level}</fg #a35252>: <light-white>{message}</light-white>\n"
+    if record["level"].name == "CRITICAL":
+        return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> | <fg #521010>{level}</fg #521010>: <light-white>{message}</light-white>\n"
+    return "<fg #5278a3>{time:MM-DD-YYYY HH:mm:ss}</fg #5278a3> | <fg #98bedf>{level}</fg #98bedf>: <light-white>{message}</light-white>\n"
+
+
+def create_logger() -> logger:
+    """
+    Configure custom logger.
+
+    :returns: logger
+    """
+    logger.remove()
+    logger.add(
+        stdout,
+        colorize=True,
+        catch=True,
+        level="TRACE",
+        format=log_formatter,
+    )
+    if settings.ENVIRONMENT == "production" and path.isdir(f"/var/log/{settings.APP_NAME}"):
+        # Datadog JSON logs
+        logger.add(
+            f"/var/log/{settings.APP_NAME}/info.json",
+            format=json_formatter,
+            rotation="200 MB",
+            level="TRACE",
+            compression="zip",
+        )
+        # Readable logs
+        logger.add(
+            f"/var/log/{settings.APP_NAME}/info.log",
+            colorize=True,
+            catch=True,
+            level="TRACE",
+            format=log_formatter,
+            rotation="200 MB",
+            compression="zip",
+        )
+    else:
+        logger.add(
+            "./logs/error.log",
+            colorize=True,
+            catch=True,
+            format=log_formatter,
+            rotation="200 MB",
+            compression="zip",
+            level="ERROR",
+        )
+    return logger
+
+
+# Custom logger
+LOGGER = create_logger()