Change logging to structlog

docs/controllers.md

@@ -14,7 +14,9 @@ be the first two parameters.
 from asgikit.requests import Request, read_json
 from asgikit.responses import respond_text, respond_redirect
 from selva.web import controller, get, post
-from loguru import logger
+import structlog
+
+logger = structlog.get_logger()
 
 
 @controller
@@ -28,7 +30,7 @@ class IndexController:
 class AdminController:
     @post("send")
     async def handle_data(self, request: Request):
-        logger.info(await read_json(request))
+        logger.info("request body", content=str(await read_json(request)))
         await respond_redirect(request.response, "/")
 ```
 
@@ -41,8 +43,7 @@ handler with the annotation `FromPath`:
 
 ```python
 from typing import Annotated
-from selva.web.converter import FromPath
-from selva.web.routing.decorator import get
+from selva.web import get, FromPath
 
 
 @get("/:path_param")

docs/logging.md

@@ -1,54 +1,57 @@
 # Logging
 
-Selva uses [loguru](https://pypi.org/project/loguru/) for logging, but provides
+Selva uses [Structlog](https://www.structlog.org) for logging and provides
 some facilities on top of it to make its usage a bit closer to other frameworks
 like Spring Boot.
 
-First, an interceptor to the standard `logging` module is configured by default,
-as suggested in <https://github.com/Delgan/loguru#entirely-compatible-with-standard-logging>.
+It is integrated with the standard library logging, so libraries that use it are logged
+through Structlog. It also enables filtering by logger name using the standard library.
 
-Second, a custom logging filter is provided in order to set the logging level for
-each package independently.
+## Why?
 
-## Configuring logging
+Nowadays, it is very likely that your application is deployed to a cloud and its
+logs are sent to an aggregator like Graylog, so a structured logging format seems
+to be the logical choice.
+
+For more information on why use structured logging, refer to the
+[Structlog documentation](https://www.structlog.org/en/stable/why.html).
+
+## Configure logging
 
 Logging is configured in the Selva configuration:
 
 ```yaml
 logging:
-  root: WARNING
-  level:
+  root: WARNING # (1)
+  level: # (2)
     application: INFO
-    application.service: TRACE
-    sqlalchemy: DEBUG
-  enable:
-    - packages_to_activate_logging
-  disabled:
-    - packages_to_deactivate_logging
+    selva: DEBUG
+  format: json # (3) 
+  setup: selva.logging.setup # (4)
 ```
 
-The `root` property is the *root* level. It is used if no other level is set for the
-package where the log comes from.
+1.  Log level of the root logger.
+2.  Mapping of logger names to log level.
+3.  Log format. Possible values are `"json"`, `"logfmt"`, `"keyvalue""` and `"console"`.
+4.  Setup function to configure logging.
 
-The `level` property defines the logging level for each package independently.
+The `format` config defines which renderer will be used. The possible values map to:
 
-The `enable` and `disable` properties lists the packages to enable or disable logging.
-This comes from loguru, as can be seen in <https://github.com/Delgan/loguru#suitable-for-scripts-and-libraries>.
+| value    | renderer                                                 |
+|----------|----------------------------------------------------------|
+| `json`     | `structlog.processors.JSONRenderer()`                    |
+| `logfmt`   | `structlog.processors.LogfmtRenderer(bool_as_flag=True)` |
+| `keyvalue` | `structlog.processors.KeyValueRenderer()`                |
+| `console`  | `structlog.dev.ConsoleRenderer()`                        |
 
-## Manual logger setup
+If not defined, `format` defaults to `"json"` if `sys.stderr.isatty() == False`,
+or `"console"` otherwise. This is done to use the `ConsoleRenderer` during development
+and the `JSONRenderer` when deploying to production.
 
-If you want full control of how loguru is configured, you can provide a logger setup
-function and reference it in the configuration file:
+## Manual logger setup
 
-=== "application/logging.py"
-
-    ```python
-    from loguru import logger
-
-
-    def setup(settings):
-        logger.configure(...)
-    ```
+If you need full control of how Structlog is configured, you can provide a logger setup
+function. You just need to reference it in the configuration file:
 
 === "configuration/settings.yaml"
 
@@ -57,5 +60,16 @@ function and reference it in the configuration file:
       setup: application.logging.setup
     ```
 
+=== "application/logging.py"
+
+    ```python
+    import structlog
+    from selva.configuration import Settings
+
+
+    def setup(settings: Settings):
+        structlog.configure(...)
+    ```
+
 The setup function receives a parameter of type `selva.configuration.Settings`,
 so you can have access to the whole settings.

docs/middleware.md

@@ -30,9 +30,11 @@ in the processing of the request:
     from datetime import datetime
 
     from asgikit.requests import Request
+    import structlog
     from selva.di import service
     from selva.web.middleware import Middleware, CallNext
-    from loguru import logger
+
+    logger = structlog.get_logger()
 
 
     @service
@@ -43,7 +45,7 @@ in the processing of the request:
             request_end = datetime.now()
 
             delta = request_end - request_start
-            logger.info("Request time: {}", delta)
+            logger.info("request duration", duration=str(delta))
     ```
 
     1. Invoke the middleware chain to process the request

examples/background_tasks/application.py

@@ -2,10 +2,12 @@
 
 from asgikit.requests import Request
 from asgikit.responses import respond_json
-from loguru import logger
+import structlog
 
 from selva.web import controller, get
 
+logger = structlog.get_logger()
+
 
 @controller
 class Controller:

examples/database/application/__init__.py

@@ -1,9 +0,0 @@
-import sys
-
-from loguru import logger
-
-logger.remove()
-logger.enable("selva")
-logger.disable("databases")
-logger.disable("aiosqlite")
-logger.add(sys.stderr, level="DEBUG")

examples/database/application/service.py

@@ -2,21 +2,23 @@
 from typing import Annotated
 
 from databases import Database
-from loguru import logger
+import structlog
 
 from selva.configuration import Settings
 from selva.di import Inject, service
 
+logger = structlog.get_logger()
+
 
 @service
 def database_factory(settings: Settings) -> Database:
     database = Database(settings.database.url)
-    logger.info("Sqlite database created")
+    logger.info("sqlite database created")
 
     yield database
 
     os.unlink(database.url.database)
-    logger.info("Sqlite database destroyed")
+    logger.info("sqlite database destroyed")
 
 
 @service
@@ -25,7 +27,7 @@ class Repository:
 
     async def initialize(self):
         await self.database.connect()
-        logger.info("Sqlite database connection opened")
+        logger.info("sqlite database connection opened")
 
         await self.database.execute(
             "create table if not exists counter(value int not null)"
@@ -34,13 +36,13 @@ async def initialize(self):
 
     async def finalize(self):
         await self.database.disconnect()
-        logger.info("Sqlite database connection closed")
+        logger.info("sqlite database connection closed")
 
     async def test(self):
         await self.database.execute("select 1")
 
     async def count(self) -> int:
         await self.database.execute("update counter set value = value + 1")
         result = await self.database.fetch_val("select value from counter")
-        logger.info("Current count: {}", result)
+        logger.info("count updated", count=result)
         return result

examples/hello_world/application.py

@@ -2,12 +2,15 @@
 
 from asgikit.requests import Request, read_json
 from asgikit.responses import respond_json
-from loguru import logger
 from pydantic import BaseModel
 
+import structlog
+
 from selva.di import Inject, service
 from selva.web import FromPath, FromQuery, controller, get, post
 
+logger = structlog.get_logger()
+
 
 class MyModel(BaseModel):
     name: str
@@ -32,7 +35,7 @@ async def greet_query(
         number: Annotated[int, FromQuery] = 1,
     ):
         greeting = self.greeter.greet(name)
-        logger.info(greeting)
+        logger.info(greeting, name=name, number=number)
         await respond_json(request.response, {"greeting": greeting, "number": number})
 
     @get("/:name")

examples/middleware/application/middleware.py

@@ -4,10 +4,13 @@
 
 from asgikit.requests import Request
 from asgikit.responses import respond_status
-from loguru import logger
+
+import structlog
 
 from selva.web.middleware import Middleware
 
+logger = structlog.get_logger()
+
 
 class TimingMiddleware(Middleware):
     async def __call__(self, chain, request: Request):
@@ -20,7 +23,7 @@ async def __call__(self, chain, request: Request):
         request_end = datetime.now()
 
         delta = request_end - request_start
-        logger.info("Request time: {}", delta)
+        logger.info("request duration", duration=str(delta))
 
 
 class LoggingMiddleware(Middleware):
@@ -35,7 +38,7 @@ async def __call__(self, chain, request: Request):
         request_line = f"{request.method} {request.path} HTTP/{request.http_version}"
         status = request.response.status
 
-        logger.info('{} "{}" {} {}', client, request_line, status.value, status.phrase)
+        logger.info("request", client=client, request_line=request_line, status=status.value, status_phrase=status.phrase)
 
 
 class AuthMiddleware(Middleware):
@@ -52,7 +55,7 @@ async def __call__(self, chain, request: Request):
 
             authn = authn.removeprefix("Basic")
             user, password = base64.urlsafe_b64decode(authn).decode().split(":")
-            logger.info("User '{}' with password '{}'", user, password)
+            logger.info("user logged in", user=user, password=password)
             request["user"] = user
 
         await chain(request)

examples/middleware/application/service.py

@@ -6,23 +6,23 @@
 DEFAULT_NAME = "World"
 
 
-class Settings(NamedTuple):
+class Config(NamedTuple):
     default_name: str
 
 
 @service
-def settings_factory() -> Settings:
+def settings_factory() -> Config:
     default_name = os.getenv("DEFAULT_NAME", DEFAULT_NAME)
-    return Settings(default_name)
+    return Config(default_name)
 
 
 @service
 class Greeter:
-    settings: Annotated[Settings, Inject]
+    config: Annotated[Config, Inject]
 
     @property
     def default_name(self):
-        return self.settings.default_name
+        return self.config.default_name
 
     def greet(self, name: str = None):
         greeted_name = name or self.default_name

examples/settings/configuration/settings.yaml

@@ -1 +1,6 @@
-message: ${MESSAGE:Hello, World!}
+message: ${MESSAGE:Hello, World!}
+
+logging:
+  root: info
+  level:
+    selva.web: debug

examples/sqlalchemy/application/model.py

@@ -8,7 +8,7 @@ class Base(DeclarativeBase):
 
 class MyModel(Base):
     __tablename__ = 'my_model'
-    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
     name: Mapped[str] = mapped_column(String(length=100))
 
     def __repr__(self):
@@ -21,7 +21,7 @@ class OtherBase(DeclarativeBase):
 
 class OtherModel(OtherBase):
     __tablename__ = 'my_model'
-    id: Mapped[int] = Column(primary_key=True, autoincrement=True)
+    id: Mapped[int] = Column(Integer, primary_key=True, autoincrement=True)
     name: Mapped[str] = Column(String(length=100))
 
     def __repr__(self):