feat: experiment log stream, to file and UI

Adds a few new logging utility classes. One to save to files with a date, one to support optional fields in formats, last to filter partial log messages.

ref: N25B-401

src/control_backend/agents/base.py

@@ -1,9 +1,10 @@
 import logging
+from abc import ABC
 
 from control_backend.core.agent_system import BaseAgent as CoreBaseAgent
 
 
-class BaseAgent(CoreBaseAgent):
+class BaseAgent(CoreBaseAgent, ABC):
     """
     The primary base class for all implementation agents.
 

src/control_backend/core/config.py

@@ -142,6 +142,18 @@ class SpeechModelSettings(BaseModel):
     openai_model_name: str = "small.en"
 
 
+class LoggingSettings(BaseModel):
+    """
+    Configuration for logging.
+
+    :ivar logging_config_file: Path to the logging configuration file.
+    :ivar experiment_logger_name: Name of the experiment logger, should match the logging config.
+    """
+
+    logging_config_file: str = ".logging_config.yaml"
+    experiment_logger_name: str = "experiment"
+
+
 class Settings(BaseSettings):
     """
     Global application settings.
@@ -163,6 +175,8 @@ class Settings(BaseSettings):
 
     ri_host: str = "localhost"
 
+    logging_settings: LoggingSettings = LoggingSettings()
+
     zmq_settings: ZMQSettings = ZMQSettings()
 
     agent_settings: AgentSettings = AgentSettings()

src/control_backend/logging/__init__.py

@@ -1 +1,4 @@
+from .dated_file_handler import DatedFileHandler as DatedFileHandler
+from .optional_field_formatter import OptionalFieldFormatter as OptionalFieldFormatter
+from .partial_filter import PartialFilter as PartialFilter
 from .setup_logging import setup_logging as setup_logging

src/control_backend/logging/dated_file_handler.py

@@ -0,0 +1,29 @@
+from datetime import datetime
+from logging import FileHandler
+from pathlib import Path
+
+
+class DatedFileHandler(FileHandler):
+    def __init__(self, file_prefix: str, **kwargs):
+        if not file_prefix:
+            raise ValueError("`file_prefix` argument cannot be empty.")
+        self._file_prefix = file_prefix
+        kwargs["filename"] = self._make_filename()
+        super().__init__(**kwargs)
+
+    def _make_filename(self) -> str:
+        filepath = Path(f"{self._file_prefix}-{datetime.now():%Y%m%d-%H%M%S}.log")
+        if not filepath.parent.is_dir():
+            filepath.parent.mkdir(parents=True, exist_ok=True)
+        return str(filepath)
+
+    def do_rollover(self):
+        self.acquire()
+        try:
+            if self.stream:
+                self.stream.close()
+
+            self.baseFilename = self._make_filename()
+            self.stream = self._open()
+        finally:
+            self.release()

src/control_backend/logging/optional_field_formatter.py

@@ -0,0 +1,67 @@
+import logging
+import re
+
+
+class OptionalFieldFormatter(logging.Formatter):
+    """
+    Logging formatter that supports optional fields marked by `?`.
+
+    Optional fields are denoted by placing a `?` after the field name inside
+    the parentheses, e.g., `%(role?)s`. If the field is not provided in the
+    log call's `extra` dict, it will use the default value from `defaults`
+    or `None` if no default is specified.
+
+    :param fmt: Format string with optional `%(name?)s` style fields.
+    :type fmt: str or None
+    :param datefmt: Date format string, passed to parent :class:`logging.Formatter`.
+    :type datefmt: str or None
+    :param style: Formatting style, must be '%'. Passed to parent.
+    :type style: str
+    :param defaults: Default values for optional fields when not provided.
+    :type defaults: dict or None
+
+    :example:
+
+        >>> formatter = OptionalFieldFormatter(
+        ...     fmt="%(asctime)s %(levelname)s %(role?)s %(message)s",
+        ...     defaults={"role": ""-""}
+        ... )
+        >>> handler = logging.StreamHandler()
+        >>> handler.setFormatter(formatter)
+        >>> logger = logging.getLogger(__name__)
+        >>> logger.addHandler(handler)
+        >>>
+        >>> logger.chat("Hello there!", extra={"role": "USER"})
+        2025-01-15 10:30:00 CHAT USER Hello there!
+        >>>
+        >>> logger.info("A logging message")
+        2025-01-15 10:30:01 INFO - A logging message
+
+    .. note::
+        Only `%`-style formatting is supported. The `{` and `$` styles are not
+        compatible with this formatter.
+
+    .. seealso::
+        :class:`logging.Formatter` for base formatter documentation.
+    """
+
+    # Match %(name?)s or %(name?)d etc.
+    OPTIONAL_PATTERN = re.compile(r"%\((\w+)\?\)([sdifFeEgGxXocrba%])")
+
+    def __init__(self, fmt=None, datefmt=None, style="%", defaults=None):
+        self.defaults = defaults or {}
+
+        self.optional_fields = set(self.OPTIONAL_PATTERN.findall(fmt or ""))
+
+        # Convert %(name?)s to %(name)s for standard formatting
+        normalized_fmt = self.OPTIONAL_PATTERN.sub(r"%(\1)\2", fmt or "")
+
+        super().__init__(normalized_fmt, datefmt, style)
+
+    def format(self, record):
+        for field, _ in self.optional_fields:
+            if not hasattr(record, field):
+                default = self.defaults.get(field, None)
+                setattr(record, field, default)
+
+        return super().format(record)

src/control_backend/logging/partial_filter.py

@@ -0,0 +1,10 @@
+import logging
+
+
+class PartialFilter(logging.Filter):
+    """
+    Class to filter any log records that have the "partial" attribute set to ``True``.
+    """
+
+    def filter(self, record):
+        return getattr(record, "partial", False) is not True

src/control_backend/logging/setup_logging.py

@@ -37,7 +37,7 @@ def add_logging_level(level_name: str, level_num: int, method_name: str | None =
     setattr(logging, method_name, log_to_root)
 
 
-def setup_logging(path: str = ".logging_config.yaml") -> None:
+def setup_logging(path: str = settings.logging_settings.logging_config_file) -> None:
     """
     Setup logging configuration of the CB. Tries to load the logging configuration from a file,
     in which we specify custom loggers, formatters, handlers, etc.
@@ -65,7 +65,7 @@ def setup_logging(path: str = ".logging_config.yaml") -> None:
 
             # Patch ZMQ PUBHandler to know about custom levels
             if custom_levels:
-                for logger_name in ("control_backend",):
+                for logger_name in config.get("loggers", {}):
                     logger = logging.getLogger(logger_name)
                     for handler in logger.handlers:
                         if isinstance(handler, PUBHandler):