feat: add trace_semantics check

ddapm_test_agent/agent.py

@@ -50,6 +50,7 @@
 from .trace_checks import CheckTraceCountHeader
 from .trace_checks import CheckTraceDDService
 from .trace_checks import CheckTracePeerService
+from .trace_checks import CheckTraceSemantics
 from .trace_checks import CheckTraceStallAsync
 from .tracerflare import TracerFlareEvent
 from .tracerflare import v1_decode as v1_tracerflare_decode
@@ -646,6 +647,7 @@ async def _handle_traces(self, request: Request, version: Literal["v0.4", "v0.5"
                         await checks.check(
                             "trace_peer_service", span=span, dd_config_env=request.get("_dd_trace_env_variables", {})
                         )
+                        await checks.check("trace_semantics", span=span)
 
                     await checks.check(
                         "trace_dd_service", trace=trace, dd_config_env=request.get("_dd_trace_env_variables", {})
@@ -1051,12 +1053,13 @@ def make_app(
     )
     checks = Checks(
         checks=[
-            CheckMetaTracerVersionHeader,
-            CheckTraceCountHeader,
-            CheckTraceContentLength,
-            CheckTraceStallAsync,
-            CheckTracePeerService,
-            CheckTraceDDService,
+            CheckMetaTracerVersionHeader(),
+            CheckTraceCountHeader(),
+            CheckTraceContentLength(),
+            CheckTraceStallAsync(),
+            CheckTracePeerService(),
+            CheckTraceDDService(),
+            CheckTraceSemantics(),
         ],
         enabled=enabled_checks,
     )

ddapm_test_agent/checks.py

@@ -8,7 +8,6 @@
 from typing import Generator
 from typing import List
 from typing import Tuple
-from typing import Type
 
 
 CHECK_TRACE: contextvars.ContextVar["CheckTrace"] = contextvars.ContextVar("check_trace")
@@ -181,10 +180,10 @@ def check(self, *args, **kwargs):
 
 @dataclasses.dataclass()
 class Checks:
-    checks: List[Type[Check]] = dataclasses.field(init=True)
+    checks: List[Check] = dataclasses.field(init=True)
     enabled: List[str] = dataclasses.field(init=True)
 
-    def _get_check(self, name: str) -> Type[Check]:
+    def _get_check(self, name: str) -> Check:
         for c in self.checks:
             if c.name == name:
                 return c
@@ -199,7 +198,7 @@ def is_enabled(self, name: str) -> bool:
 
     async def check(self, name: str, *args: Any, **kwargs: Any) -> None:
         """Find and run the check with the given ``name`` if it is enabled."""
-        check = self._get_check(name)()
+        check = self._get_check(name)
 
         if self.is_enabled(name):
             # Register the check with the current trace

ddapm_test_agent/trace_checks.py

@@ -5,7 +5,10 @@
 from typing import List
 
 from aiohttp.web import Request
+from jsonschema import ValidationError
+from jsonschema import validate
 from multidict import CIMultiDictProxy
+import requests
 
 from .checks import Check
 from .trace import Span
@@ -221,3 +224,36 @@ def check(self, trace: List[Span], dd_config_env: Dict[str, str]) -> None:
                 else:
                     log.debug(f"Successfully completed ``service`` name Span Check for Span: {span['name']}")
         return
+
+
+SCHEMA_URL = "https://raw.githubusercontent.com/DataDog/schema/main/semantic-core/v1/schema.json"
+
+
+class CheckTraceSemantics(Check):
+    name = "trace_semantics"
+    description = """
+The trace should follow semantic conventions defined by semantic-core.
+More info here: https://github.com/datadog/semantic-core.
+""".strip()
+    schema = None
+
+    def __init__(self):
+        log.debug("Initializing CheckTraceSemantics")
+
+        resp = requests.get(SCHEMA_URL)
+        if resp.status_code != 200:
+            log.fatal(f"Failed to download trace semantics schema: {resp}")
+
+        log.debug("Successfully downloaded semantic-core JSON Schema")
+
+        self.schema = resp.json()
+        super().__init__()
+
+    def check(self, span: Span) -> None:
+        log.info("Performing ``Trace Semantics`` Span Check")
+
+        try:
+            validate(instance=span, schema=self.schema)
+            log.debug(f"Span Check ``trace_semantics`` succeeded for Span {span['name']}")
+        except ValidationError as err:
+            self.fail(json.dumps(span, indent=4) + f"\nSpan '{span['name']}' failed semantic validation: {err}.")

setup.py

@@ -33,6 +33,7 @@
         "requests",
         "typing_extensions",
         "yarl",
+        "jsonschema",
     ],
     tests_require=testing_deps,
     setup_requires=["setuptools_scm"],