fix(internal): properly convert PEP 440 version to SemVer for RCM client [backport #4910 to 1.7]

ddtrace/internal/remoteconfig/client.py

@@ -199,15 +199,33 @@ def __init__(self):
             if container_id is not None:
                 self._headers["Datadog-Container-Id"] = container_id
 
+        # The library uses a PEP 440-compliant versioning scheme, but the
+        # RCM spec requires that we use a SemVer-compliant version.
+        #
+        # However, we may have versions like:
+        #
+        #   - 1.7.1.dev3+gf258c7d9
+        #   - 1.7.1rc2.dev3+gf258c7d9
+        #
+        # Which are not Semver-compliant.
+        #
+        # The easiest fix is to replace the first occurrence of "rc" or
+        # ".dev" with "-rc" or "-dev" to make them compliant.
+        #
+        # Other than X.Y.Z, we are allowed `-<dot separated pre-release>+<build identifier>`
+        # https://semver.org/#backusnaur-form-grammar-for-valid-semver-versions
+        #
+        # e.g. 1.7.1-rc2.dev3+gf258c7d9 is valid
+        tracer_version = ddtrace.__version__
+        if "rc" in tracer_version:
+            tracer_version = tracer_version.replace("rc", "-rc", 1)
+        elif ".dev" in tracer_version:
+            tracer_version = tracer_version.replace(".dev", "-dev", 1)
+
         self._client_tracer = dict(
             runtime_id=runtime.get_runtime_id(),
             language="python",
-            # The library uses a PEP 440-compliant versioning scheme, but the
-            # RCM spec requires that we use a SemVer-compliant version. We only
-            # expect that the first occurrence of "rc" in the version string to
-            # break the SemVer format, so we replace it with "-rc" for
-            # simplicity.
-            tracer_version=ddtrace.__version__.replace("rc", "-rc", 1),
+            tracer_version=tracer_version,
             service=ddtrace.config.service,
             env=ddtrace.config.env,
             app_version=ddtrace.config.version,