chore(crashtracking): enable wait_for_receiver field to be configur…

…ed via env var (#10233)

### Change Overview
This PR enables the `wait_for_receiver` field to be set via
`DD_CRASHTRACKING_WAIT_FOR_RECEIVER` environment variable. If unset, the
default is `true`.

### Motivation
[System-tests for
crashtracking](DataDog/system-tests#2884)
exposed that the Python crashtracker needs the `wait_for_receiver` field
to be set to `true` to capture crashes and reliably send telemetry
events to the agent. While set to `false`, telemetry events for crashes
would work very rarely. When set to `true`, this would become reliably
consistent.

The value for `wait_for_receiver` is [unset in
`libdatadog`](https://github.com/DataDog/libdatadog/blob/16528ffee456f7af5fe9ad80a6294fb5dcd38918/crashtracker/src/shared/configuration.rs#L28),
which means it is set to `false` by default. This default needs to be
updated on the `libdatadog` end. However, in order to unblock
crashtracking functionality for `dd-trace-py`, we are also enabling this
to be configured on the `dd-trace-py` side as well.

## Checklist
- [x] PR author has checked that all the criteria below are met
- The PR description includes an overview of the change
- The PR description articulates the motivation for the change
- The change includes tests OR the PR description describes a testing
strategy
- The PR description notes risks associated with the change, if any
- Newly-added code is easy to change
- The change follows the [library release note
guidelines](https://ddtrace.readthedocs.io/en/stable/releasenotes.html)
- The change includes or references documentation updates if necessary
- Backport labels are set (if
[applicable](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting))

## Reviewer Checklist
- [x] Reviewer has checked that all the criteria below are met 
- Title is accurate
- All changes are related to the pull request's stated goal
- Avoids breaking
[API](https://ddtrace.readthedocs.io/en/stable/versioning.html#interfaces)
changes
- Testing strategy adequately addresses listed risks
- Newly-added code is easy to change
- Release note makes sense to a user of the library
- If necessary, author has acknowledged and discussed the performance
implications of this PR as reported in the benchmarks PR comment
- Backport labels are set in a manner that is consistent with the
[release branch maintenance
policy](https://ddtrace.readthedocs.io/en/latest/contributing.html#backporting)

ddtrace/internal/core/crashtracking.py

@@ -35,6 +35,7 @@ def start() -> bool:
     crashtracker.set_runtime_id(get_runtime_id())
     crashtracker.set_library_version(version.get_version())
     crashtracker.set_alt_stack(bool(crashtracker_config.alt_stack))
+    crashtracker.set_wait_for_receiver(bool(crashtracker_config.wait_for_receiver))
     if crashtracker_config.stacktrace_resolver == "fast":
         crashtracker.set_resolve_frames_fast()
     elif crashtracker_config.stacktrace_resolver == "full":

ddtrace/internal/datadog/profiling/crashtracker/_crashtracker.pyi

@@ -11,6 +11,7 @@ def set_library_version(profiler_version: StringType) -> None: ...
 def set_stdout_filename(filename: StringType) -> None: ...
 def set_stderr_filename(filename: StringType) -> None: ...
 def set_alt_stack(alt_stack: bool) -> None: ...
+def set_wait_for_receiver(wait: bool) -> None: ...
 def set_resolve_frames_disable() -> None: ...
 def set_resolve_frames_fast() -> None: ...
 def set_resolve_frames_full() -> None: ...

ddtrace/internal/datadog/profiling/crashtracker/_crashtracker.pyx

@@ -28,6 +28,7 @@ cdef extern from "crashtracker_interface.hpp":
     void crashtracker_set_stdout_filename(string_view filename)
     void crashtracker_set_stderr_filename(string_view filename)
     void crashtracker_set_alt_stack(bint alt_stack)
+    void crashtracker_set_wait_for_receiver(bint wait)
     void crashtracker_set_resolve_frames_disable()
     void crashtracker_set_resolve_frames_fast()
     void crashtracker_set_resolve_frames_full()
@@ -98,6 +99,10 @@ def set_alt_stack(alt_stack: bool) -> None:
     crashtracker_set_alt_stack(alt_stack)
 
 
+def set_wait_for_receiver(wait: bool) -> None:
+    crashtracker_set_wait_for_receiver(wait)
+
+
 def set_resolve_frames_disable() -> None:
     crashtracker_set_resolve_frames_disable()
 

ddtrace/internal/datadog/profiling/dd_wrapper/include/crashtracker.hpp

@@ -32,6 +32,7 @@ class Crashtracker
 {
   private:
     bool create_alt_stack = false;
+    bool wait_for_receiver = true;
     std::optional<std::string> stderr_filename{ std::nullopt };
     std::optional<std::string> stdout_filename{ std::nullopt };
     std::string path_to_receiver_binary;
@@ -71,6 +72,7 @@ class Crashtracker
     void set_library_version(std::string_view _library_version);
     void set_url(std::string_view _url);
     void set_tag(std::string_view _key, std::string_view _value);
+    void set_wait_for_receiver(bool _wait);
 
     void set_create_alt_stack(bool _create_alt_stack);
     void set_stderr_filename(std::string_view _stderr_filename);

ddtrace/internal/datadog/profiling/dd_wrapper/include/crashtracker_interface.hpp

@@ -19,6 +19,7 @@ extern "C"
     void crashtracker_set_stdout_filename(std::string_view filename);
     void crashtracker_set_stderr_filename(std::string_view filename);
     void crashtracker_set_alt_stack(bool alt_stack);
+    void crashtracker_set_wait_for_receiver(bool wait);
     void crashtracker_set_resolve_frames_disable();
     void crashtracker_set_resolve_frames_fast();
     void crashtracker_set_resolve_frames_full();

ddtrace/internal/datadog/profiling/dd_wrapper/src/crashtracker.cpp

@@ -12,6 +12,12 @@ Datadog::Crashtracker::set_create_alt_stack(bool _create_alt_stack)
     create_alt_stack = _create_alt_stack;
 }
 
+void
+Datadog::Crashtracker::set_wait_for_receiver(bool _wait)
+{
+    wait_for_receiver = _wait;
+}
+
 void
 Datadog::Crashtracker::set_env(std::string_view _env)
 {
@@ -122,7 +128,7 @@ Datadog::Crashtracker::get_config()
     config.endpoint = ddog_endpoint_from_url(to_slice(url));
     config.resolve_frames = resolve_frames;
     config.timeout_secs = timeout_secs;
-
+    config.wait_for_receiver = wait_for_receiver;
     return config;
 }
 

ddtrace/internal/datadog/profiling/dd_wrapper/src/crashtracker_interface.cpp

@@ -82,6 +82,12 @@ crashtracker_set_alt_stack(bool alt_stack) // cppcheck-suppress unusedFunction
     crashtracker.set_create_alt_stack(alt_stack);
 }
 
+void
+crashtracker_set_wait_for_receiver(bool wait) // cppcheck-suppress unusedFunction
+{
+    crashtracker.set_wait_for_receiver(wait);
+}
+
 void
 crashtracker_set_resolve_frames_disable() // cppcheck-suppress unusedFunction
 {

ddtrace/settings/crashtracker.py

@@ -101,5 +101,13 @@ class CrashtrackingConfig(En):
         "This is generally useful only for dd-trace-py development.",
     )
 
+    wait_for_receiver = En.v(
+        bool,
+        "wait_for_receiver",
+        default=True,
+        help_type="Boolean",
+        help="Whether to wait for the crashtracking receiver",
+    )
+
 
 config = CrashtrackingConfig()