feat: Allow configuring keep_alive via environment variable (#4366)

This commit enables the `keep_alive` option to be set via the
`SENTRY_KEEP_ALIVE` environment variable. When both the environment
variable and the argument are provided, the argument takes precedence.

Closes #4354

Author: szokeasaurusrex

sentry_sdk/client.py

@@ -142,6 +142,11 @@ def _get_options(*args, **kwargs):
         )
         rv["socket_options"] = None
 
+    if rv["keep_alive"] is None:
+        rv["keep_alive"] = (
+            env_to_bool(os.environ.get("SENTRY_KEEP_ALIVE"), strict=True) or False
+        )
+
     if rv["enable_tracing"] is not None:
         warnings.warn(
             "The `enable_tracing` parameter is deprecated. Please use `traces_sample_rate` instead.",

sentry_sdk/consts.py

@@ -578,7 +578,7 @@ def __init__(
         ignore_errors=[],  # type: Sequence[Union[type, str]]  # noqa: B006
         max_request_body_size="medium",  # type: str
         socket_options=None,  # type: Optional[List[Tuple[int, int, int | bytes]]]
-        keep_alive=False,  # type: bool
+        keep_alive=None,  # type: Optional[bool]
         before_send=None,  # type: Optional[EventProcessor]
         before_breadcrumb=None,  # type: Optional[BreadcrumbProcessor]
         debug=None,  # type: Optional[bool]

tests/test_client.py

@@ -1,3 +1,4 @@
+import contextlib
 import os
 import json
 import subprocess
@@ -1496,3 +1497,66 @@ def test_dropped_transaction(sentry_init, capture_record_lost_event_calls, test_
 def test_enable_tracing_deprecated(sentry_init, enable_tracing):
     with pytest.warns(DeprecationWarning):
         sentry_init(enable_tracing=enable_tracing)
+
+
+def make_options_transport_cls():
+    """Make an options transport class that captures the options passed to it."""
+    # We need a unique class for each test so that the options are not
+    # shared between tests.
+
+    class OptionsTransport(Transport):
+        """Transport that captures the options passed to it."""
+
+        def __init__(self, options):
+            super().__init__(options)
+            type(self).options = options
+
+        def capture_envelope(self, _):
+            pass
+
+    return OptionsTransport
+
+
+@contextlib.contextmanager
+def clear_env_var(name):
+    """Helper to clear the a given environment variable,
+    and restore it to its original value on exit."""
+    old_value = os.environ.pop(name, None)
+
+    try:
+        yield
+    finally:
+        if old_value is not None:
+            os.environ[name] = old_value
+        elif name in os.environ:
+            del os.environ[name]
+
+
+@pytest.mark.parametrize(
+    ("env_value", "arg_value", "expected_value"),
+    [
+        (None, None, False),  # default
+        ("0", None, False),  # env var false
+        ("1", None, True),  # env var true
+        (None, False, False),  # arg false
+        (None, True, True),  # arg true
+        # Argument overrides environment variable
+        ("0", True, True),  # env false, arg true
+        ("1", False, False),  # env true, arg false
+    ],
+)
+def test_keep_alive(env_value, arg_value, expected_value):
+    transport_cls = make_options_transport_cls()
+    keep_alive_kwarg = {} if arg_value is None else {"keep_alive": arg_value}
+
+    with clear_env_var("SENTRY_KEEP_ALIVE"):
+        if env_value is not None:
+            os.environ["SENTRY_KEEP_ALIVE"] = env_value
+
+        sentry_sdk.init(
+            dsn="http://[email protected]/123",
+            transport=transport_cls,
+            **keep_alive_kwarg,
+        )
+
+    assert transport_cls.options["keep_alive"] is expected_value