Add pre and post instrument entry points

Fixes open-telemetry#1982

opentelemetry-instrumentation/README.rst

@@ -16,14 +16,6 @@ Installation
 
 This package provides a couple of commands that help automatically instruments a program:
 
-.. note::
-    You need to install a distro package to get auto instrumentation working. The ``opentelemetry-distro``
-    package contains the default distro and automatically configures some of the common options for users.
-    For more info about ``opentelemetry-distro`` check `here <https://opentelemetry-python.readthedocs.io/en/latest/examples/distro/README.html>`__
-    ::
-
-        pip install opentelemetry-distro[otlp]
-
 
 opentelemetry-bootstrap
 -----------------------

opentelemetry-instrumentation/src/opentelemetry/instrumentation/auto_instrumentation/sitecustomize.py

@@ -12,124 +12,54 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import sys
+
 from logging import getLogger
-from os import environ, path
+from os import environ
 from os.path import abspath, dirname, pathsep
 from re import sub
 
 from pkg_resources import iter_entry_points
 
-from opentelemetry.environment_variables import (
-    OTEL_PYTHON_DISABLED_INSTRUMENTATIONS,
-)
 from opentelemetry.instrumentation.dependencies import (
     get_dist_dependency_conflicts,
 )
-from opentelemetry.instrumentation.distro import BaseDistro, DefaultDistro
-
-logger = getLogger(__file__)
-
+from opentelemetry.instrumentation.environment_variables import (
+    OTEL_PYTHON_DISABLED_INSTRUMENTATIONS,
+)
 
-def _load_distros() -> BaseDistro:
-    for entry_point in iter_entry_points("opentelemetry_distro"):
-        try:
-            distro = entry_point.load()()
-            if not isinstance(distro, BaseDistro):
-                logger.debug(
-                    "%s is not an OpenTelemetry Distro. Skipping",
-                    entry_point.name,
-                )
-                continue
-            logger.debug(
-                "Distribution %s will be configured", entry_point.name
-            )
-            return distro
-        except Exception as exc:  # pylint: disable=broad-except
-            logger.exception(
-                "Distribution %s configuration failed", entry_point.name
-            )
-            raise exc
-    return DefaultDistro()
+_logger = getLogger(__file__)
 
 
-def _load_instrumentors(distro):
-    package_to_exclude = environ.get(OTEL_PYTHON_DISABLED_INSTRUMENTATIONS, [])
-    if isinstance(package_to_exclude, str):
-        package_to_exclude = package_to_exclude.split(",")
-        # to handle users entering "requests , flask" or "requests, flask" with spaces
-        package_to_exclude = [x.strip() for x in package_to_exclude]
+for entry_point in iter_entry_points("opentelemetry-pre-instrument"):
+    entry_point.load()()
 
-    for entry_point in iter_entry_points("opentelemetry_instrumentor"):
-        if entry_point.name in package_to_exclude:
-            logger.debug(
-                "Instrumentation skipped for library %s", entry_point.name
-            )
-            continue
+try:
+    disabled_instrumentations = set(
+        environ.get(OTEL_PYTHON_DISABLED_INSTRUMENTATIONS, "").split()
+    )
 
-        try:
-            conflict = get_dist_dependency_conflicts(entry_point.dist)
-            if conflict:
-                logger.debug(
-                    "Skipping instrumentation %s: %s",
-                    entry_point.name,
-                    conflict,
-                )
-                continue
+    for entry_point in iter_entry_points("opentelemetry-instrumentor"):
+        if entry_point.name in disabled_instrumentations:
+            _logger.debug("Instrumentation skipped for %s", entry_point.name)
 
-            # tell instrumentation to not run dep checks again as we already did it above
-            distro.load_instrumentor(entry_point, skip_dep_check=True)
-            logger.debug("Instrumented %s", entry_point.name)
-        except Exception as exc:  # pylint: disable=broad-except
-            logger.exception("Instrumenting of %s failed", entry_point.name)
-            raise exc
+        conflicts = get_dist_dependency_conflicts(entry_point.dist)
 
+        if conflicts is not None:
 
-def _load_configurators():
-    configured = None
-    for entry_point in iter_entry_points("opentelemetry_configurator"):
-        if configured is not None:
-            logger.warning(
-                "Configuration of %s not loaded, %s already loaded",
+            _logger.debug(
+                "Skipping instrumentation %s: %s",
                 entry_point.name,
-                configured,
+                conflicts,
             )
-            continue
-        try:
-            entry_point.load()().configure()  # type: ignore
-            configured = entry_point.name
-        except Exception as exc:  # pylint: disable=broad-except
-            logger.exception("Configuration of %s failed", entry_point.name)
-            raise exc
-
-
-def initialize():
-    try:
-        distro = _load_distros()
-        distro.configure()
-        _load_configurators()
-        _load_instrumentors(distro)
-    except Exception:  # pylint: disable=broad-except
-        logger.exception("Failed to auto initialize opentelemetry")
-    finally:
-        environ["PYTHONPATH"] = sub(
-            r"{}{}?".format(dirname(abspath(__file__)), pathsep),
-            "",
-            environ["PYTHONPATH"],
-        )
-
-
-if (
-    hasattr(sys, "argv")
-    and sys.argv[0].split(path.sep)[-1] == "celery"
-    and "worker" in sys.argv[1:]
-):
-    from celery.signals import worker_process_init  # pylint:disable=E0401
 
-    @worker_process_init.connect(weak=False)
-    def init_celery(*args, **kwargs):
-        initialize()
+        entry_point.load().instrument(skip_dep_check=True)
 
+finally:
+    environ["PYTHONPATH"] = sub(
+        r"{}{}?".format(dirname(abspath(__file__)), pathsep),
+        "",
+        environ["PYTHONPATH"],
+    )
 
-else:
-    initialize()
+for entry_point in iter_entry_points("opentelemetry-post-instrument"):
+    entry_point.load()()

opentelemetry-instrumentation/src/opentelemetry/instrumentation/environment_variables/__init__.py

@@ -0,0 +1,21 @@
+# Copyright The OpenTelemetry Authors
+#
+# Licensed 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.
+
+
+OTEL_PYTHON_DISABLED_INSTRUMENTATIONS = "OTEL_PYTHON_DISABLED_INSTRUMENTATIONS"
+"""
+.. envvar:: OTEL_PYTHON_DISABLED_INSTRUMENTATIONS
+
+Space-separated string of `opentelemetry-instrumentor` entry point names.
+"""