feat(tracing): support http server error status configuration (#10723)

DD_TRACE_HTTP_SERVER_ERROR_STATUSES can only be enabled via the
programmatic api. This PR adds an environment variable that can be used
to update this configuration.

## 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
- [ ] 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/settings/config.py

@@ -326,7 +326,7 @@ class Config(object):
     """
 
     class _HTTPServerConfig(object):
-        _error_statuses = "500-599"  # type: str
+        _error_statuses = os.getenv("DD_TRACE_HTTP_SERVER_ERROR_STATUSES", "500-599")  # type: str
         _error_ranges = get_error_ranges(_error_statuses)  # type: List[Tuple[int, int]]
 
         @property

docs/configuration.rst

@@ -454,6 +454,14 @@ The following environment variables for the tracer are supported:
      default: True
      description: Send query strings in http.url tag in http server integrations.
 
+   DD_TRACE_HTTP_SERVER_ERROR_STATUSES:
+     type: String
+     default: "500-599"
+     description: |
+        Comma-separated list of HTTP status codes that should be considered errors when returned by an HTTP request.
+        Multiple comma separated error ranges can be set (ex:  ``200,400-404,500-599``).
+        The status codes are used to set the ``error`` field on the span.
+
    DD_TRACE_METHODS:
      type: String
      default: ""

releasenotes/notes/support_http_client_error_status_env-acdf049c64330a20.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    tracing: Adds ``DD_TRACE_HTTP_CLIENT_ERROR_STATUSES`` environment variable to configure the list of HTTP status codes that should be considered errors when instrumenting HTTP severs.

tests/tracer/test_trace_utils.py

@@ -505,6 +505,26 @@ def test_set_http_meta_custom_errors(mock_log, span, int_config, error_codes, st
         mock_log.exception.assert_not_called()
 
 
+@pytest.mark.subprocess(env={"DD_TRACE_HTTP_SERVER_ERROR_STATUSES": "404-412"})
+def test_set_http_meta_custom_errors_via_env():
+    from ddtrace import config
+    from ddtrace import tracer
+    from ddtrace.contrib.trace_utils import set_http_meta
+
+    config._add("myint", dict())
+    with tracer.trace("error") as span1:
+        set_http_meta(span1, config.myint, status_code=405)
+        assert span1.error == 1
+
+    with tracer.trace("noterror") as span2:
+        set_http_meta(span2, config.myint, status_code=403)
+        assert span2.error == 0
+
+    with tracer.trace("noterror2") as span3:
+        set_http_meta(span3, config.myint, status_code=413)
+        assert span3.error == 0
+
+
 @mock.patch("ddtrace.contrib.trace_utils._store_headers")
 def test_set_http_meta_no_headers(mock_store_headers, span, int_config):
     assert int_config.myint.is_header_tracing_configured is False