howardyoo commented on code in PR #37948: URL: https://github.com/apache/airflow/pull/37948#discussion_r1565189095
########## airflow/traces/tracer.py: ########## @@ -0,0 +1,280 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one +# or more contributor license agreements. See the NOTICE file +# distributed with this work for additional information +# regarding copyright ownership. The ASF licenses this file +# to you under the Apache License, Version 2.0 (the +# "License"); you may not use this file except in compliance +# with the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, +# software distributed under the License is distributed on an +# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +# KIND, either express or implied. See the License for the +# specific language governing permissions and limitations +# under the License. +from __future__ import annotations + +import inspect +import logging +import socket +from typing import TYPE_CHECKING, Any, Callable + +from airflow.configuration import conf +from airflow.typing_compat import Protocol + +log = logging.getLogger(__name__) + + +def gen_context(trace_id, span_id): + """Generate span context from trace_id and span_id.""" + from airflow.traces.otel_tracer import gen_context as otel_gen_context + + return otel_gen_context(trace_id, span_id) + + +def gen_links_from_kv_list(list): + """Generate links from kv list of {trace_id:int, span_id:int}.""" + from airflow.traces.otel_tracer import gen_links_from_kv_list + + return gen_links_from_kv_list(list) + + +def span(func): + """Decorate a function with span.""" + + def wrapper(*args, **kwargs): + func_name = func.__name__ + qual_name = func.__qualname__ + module_name = func.__module__ + if "." in qual_name: + component = f"{qual_name.rsplit('.', 1)[0]}" + else: + component = module_name + with Trace.start_span(span_name=func_name, component=component): + if len(inspect.signature(func).parameters) > 0: + return func(*args, **kwargs) + else: + return func() + + return wrapper + + +class EmptyContext: + """If no Tracer is configured, EmptyContext is used as a fallback.""" + + def __init__(self): + self.trace_id = 1 + + +class EmptySpan: + """If no Tracer is configured, EmptySpan is used as a fallback.""" + + def __enter__(self): + """Enter.""" + return self + + def __exit__(self, *args, **kwargs): + """Exit.""" + pass + + def __call__(self, obj): + """Call.""" + return obj + + def get_span_context(self): + """Get span context.""" + return EMPTY_CTX + + def set_attribute(self, key, value) -> None: + """Set an attribute to the span.""" + pass + + def set_attributes(self, attributes) -> None: + """Set multiple attributes at once.""" + pass + + def add_event( + self, + name: str, + attributes: Any | None = None, + timestamp: int | None = None, + ) -> None: + """Add event to span.""" + pass + + def add_link( + self, + context: Any, + attributes: Any | None = None, + ) -> None: + """Add link to the span.""" + pass + + def end(self, end_time=None, *args, **kwargs) -> None: + """End.""" + pass + + +EMPTY_SPAN = EmptySpan() +EMPTY_CTX = EmptyContext() + + +class Tracer(Protocol): + """This class is only used for TypeChecking (for IDEs, mypy, etc).""" + + instance: Tracer | EmptyTrace | None = None + + @classmethod + def get_tracer(cls, component): + """Get a tracer.""" + raise NotImplementedError() + + @classmethod + def start_span( + cls, + span_name: str, + component: str | None = None, + parent_sc=None, + span_id=None, + links=None, + start_time=None, + ): + """Start a span.""" + raise NotImplementedError() + + @classmethod + def use_span(cls, span): + """Use a span as current.""" + raise NotImplementedError() + + @classmethod + def get_current_span(self): + raise NotImplementedError() + + @classmethod + def start_span_from_dagrun( + cls, + dagrun, + span_name=None, + service_name=None, + component=None, + links=None, + ): + """Start a span from dagrun.""" + raise NotImplementedError() + + @classmethod + def start_span_from_taskinstance( + cls, + ti, + span_name=None, + component=None, + child=False, + links=None, + ): + """Start a span from taskinstance.""" + raise NotImplementedError() + + +class EmptyTrace: + """If no Tracer is configured, EmptyTracer is used as a fallback.""" + + @classmethod + def get_tracer( + cls, + component: str, + trace_id: int | None = None, + span_id: int | None = None, + ): + """Get a tracer using provided node id and trace id.""" + return cls + + @classmethod + def start_span( + cls, + span_name: str, + component: str | None = None, + parent_sc=None, + span_id=None, + links=None, + start_time=None, + ) -> EmptySpan: + """Start a span.""" + return EMPTY_SPAN + + @classmethod + def use_span(cls, span) -> EmptySpan: + """Use a span as current.""" + return EMPTY_SPAN + + @classmethod + def get_current_span(self) -> EmptySpan: + """Get the current span.""" + return EMPTY_SPAN + + @classmethod + def start_span_from_dagrun( + cls, + dagrun, + span_name=None, + service_name=None, + component=None, + links=None, + ) -> EmptySpan: + """Start a span from dagrun.""" + return EMPTY_SPAN + + @classmethod + def start_span_from_taskinstance( + cls, + ti, + span_name=None, + component=None, + child=False, + links=None, + ) -> EmptySpan: + """Start a span from taskinstance.""" + return EMPTY_SPAN + + +class _Trace(type): + factory: Callable + instance: Tracer | EmptyTrace | None = None + + def __getattr__(cls, name: str) -> str: + if not cls.instance: + try: + cls.instance = cls.factory() + except (socket.gaierror, ImportError) as e: + log.error("Could not configure Trace: %s, using EmptyTrace instead.", e) + cls.instance = EmptyTrace() + return getattr(cls.instance, name) + + def __init__(cls, *args, **kwargs) -> None: + super().__init__(cls) + if not hasattr(cls.__class__, "factory"): + if conf.has_option("traces", "otel_on") and conf.getboolean("traces", "otel_on"): + from airflow.traces import otel_tracer + + cls.__class__.factory = otel_tracer.get_otel_tracer + else: + cls.__class__.factory = EmptyTrace + + @classmethod + def get_constant_tags(cls) -> str | None: + """Get constant tags to add to all traces.""" + tags_in_string = conf.get("traces", "tags", fallback=None) + if not tags_in_string: + return None + return tags_in_string + + +if TYPE_CHECKING: + Trace: EmptyTrace +else: + + class Trace(metaclass=_Trace): + """Empty class for Trace - we use metaclass to inject the right one.""" Review Comment: I do agree, but I wanted to follow this pattern as otel metrics support followed the same pattern as well. For the future, this might be handy if there is a need to support more than one tracer. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@airflow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
