function.logging

 1# Copyright 2023 The Crossplane Authors.
 2#
 3# Licensed under the Apache License, Version 2.0 (the "License");
 4# you may not use this file except in compliance with the License.
 5# You may obtain a copy of the License at
 6#
 7#     http://www.apache.org/licenses/LICENSE-2.0
 8#
 9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""Logging utilities for composition functions."""
16
17import enum
18import logging
19
20import structlog
21
22
23class Level(enum.Enum):
24    """Supported log levels."""
25
26    DISABLED = 0
27    DEBUG = 1
28    INFO = 2
29
30
31def configure(level: Level = Level.INFO) -> None:
32    """Configure logging.
33
34    Args:
35        level: What log level to enable.
36
37    Must be called before calling get_logger. When debug logging is enabled logs
38    will be printed in a human readable fashion. When not enabled, logs will be
39    printed as JSON lines.
40    """
41
42    def dropper(logger, method_name, event_dict):  # noqa: ARG001  # We need this signature.
43        raise structlog.DropEvent
44
45    if level == Level.DISABLED:
46        structlog.configure(processors=[dropper])
47        return
48
49    processors = [
50        structlog.stdlib.add_log_level,
51        structlog.processors.CallsiteParameterAdder(
52            {
53                structlog.processors.CallsiteParameter.FILENAME,
54                structlog.processors.CallsiteParameter.LINENO,
55            }
56        ),
57    ]
58
59    if level == Level.DEBUG:
60        structlog.configure(
61            processors=[
62                *processors,
63                structlog.processors.TimeStamper(fmt="iso"),
64                structlog.dev.ConsoleRenderer(),
65            ]
66        )
67        return
68
69    # Attempt to match function-sdk-go's production logger.
70    structlog.configure(
71        processors=[
72            *processors,
73            structlog.processors.dict_tracebacks,
74            structlog.processors.TimeStamper(key="ts"),
75            structlog.processors.EventRenamer(to="msg"),
76            structlog.processors.JSONRenderer(),
77        ],
78        wrapper_class=structlog.make_filtering_bound_logger(logging.INFO),
79    )
80
81
82def get_logger() -> structlog.stdlib.BoundLogger:
83    """Get a logger.
84
85    You must call configure before calling get_logger.
86    """
87    return structlog.stdlib.get_logger()