Add distro metadata generator

RELEASING.md

@@ -39,8 +39,14 @@ How to release a new version of the `splunk-opentelemetry` project:
 14) Navigate to Pipelines in the GitLab repo, click the download button for the signing job that just ran,
     and select the 'checksum-signing-job' artifact
     - this will download a tarball containing the package files, `checksums.txt`, and `checksums.txt.asc`
-15) Navigate to the Splunk OTel Python repo and create a New Release
+15) Generate the release metadata file from the repository root with the release commit checked out
+    - with your local virtualenv active and the local package installed, run
+      `python tools/generate_metadata.py`
+    - alternatively, run `hatch run python tools/generate_metadata.py`
+    - either command creates `metadata.yaml` for upload as a GitHub Release asset
+16) Navigate to the Splunk OTel Python repo and create a New Release
     - create a new tag on publish with the tag name you created in step 11
     - set the title to that tag name (e.g. `v2.7.0`)
-    - unpack the tarball from step 14 and drag its contents onto the attachments section of the New Release page
+    - unpack the tarball from step 14 and drag its contents and `metadata.yaml` onto the attachments section of the
+      New Release page
     - Leave the defaults selected and click Publish

tests/test_generate_metadata.py

@@ -0,0 +1,127 @@
+from pathlib import Path
+
+from tools.generate_metadata import (
+    build_instrumentation,
+    dependency_stability,
+    dump_yaml,
+    generate_metadata,
+    load_toml_bytes,
+    parse_requirement,
+)
+
+
+def write_project(root: Path) -> None:
+    package_dir = root / "src" / "splunk_otel"
+    package_dir.mkdir(parents=True)
+    (package_dir / "__about__.py").write_text('__version__ = "9.8.7"\n')
+    (root / "pyproject.toml").write_text(
+        """
+[project]
+dependencies = [
+  "opentelemetry-api==1.2.3",
+  "opentelemetry-sdk==1.2.3",
+  "opentelemetry-instrumentation==0.4b5",
+  "opentelemetry-instrumentation-system-metrics==0.4b5",
+  "opentelemetry-opamp-client==0.1b0",
+  "wrapt>=1.0.0,<2.0.0",
+]
+"""
+    )
+
+
+def write_contrib(root: Path) -> None:
+    instrumentation = root / "instrumentation" / "opentelemetry-instrumentation-example"
+    instrumentation.mkdir(parents=True)
+    (instrumentation / "pyproject.toml").write_text(
+        """
+[project]
+name = "opentelemetry-instrumentation-example"
+description = "Example instrumentation"
+dependencies = ["opentelemetry-instrumentation == 0.4b5"]
+
+[project.optional-dependencies]
+instruments = ["example-lib >= 1.0, < 2.0"]
+
+[project.entry-points.opentelemetry_instrumentor]
+example = "opentelemetry.instrumentation.example:ExampleInstrumentor"
+"""
+    )
+
+
+def test_parse_requirement_normalizes_exact_pins() -> None:
+    assert parse_requirement("opentelemetry-api==1.2.3") == ("opentelemetry-api", "1.2.3")
+    assert parse_requirement("wrapt>=1.0.0,<2.0.0") == ("wrapt", ">=1.0.0,<2.0.0")
+
+
+def test_dependency_stability_uses_prerelease_versions() -> None:
+    assert dependency_stability("1.41.0") == "stable"
+    assert dependency_stability(">=6.33.5") == "stable"
+    assert dependency_stability("0.62b0") == "experimental"
+    assert dependency_stability("1.42.0rc1") == "experimental"
+    assert dependency_stability("1.42.0.dev") == "experimental"
+
+
+def test_build_instrumentation_from_pyproject() -> None:
+    pyproject = load_toml_bytes(
+        b"""
+[project]
+name = "opentelemetry-instrumentation-flask"
+description = "Flask instrumentation"
+
+[project.optional-dependencies]
+instruments = ["flask >= 1.0"]
+
+[project.entry-points.opentelemetry_instrumentor]
+flask = "opentelemetry.instrumentation.flask:FlaskInstrumentor"
+"""
+    )
+
+    instrumentation = build_instrumentation(
+        "instrumentation/opentelemetry-instrumentation-flask/pyproject.toml",
+        pyproject,
+    )
+
+    assert instrumentation is not None
+    assert instrumentation["keys"] == ["flask"]
+    assert instrumentation["instrumented_components"] == [
+        {
+            "name": "flask",
+            "supported_versions": "flask >= 1.0",
+        }
+    ]
+    assert instrumentation["support"] == "community"
+    assert instrumentation["stability"] == "experimental"
+
+
+def test_generate_metadata_shape(tmp_path: Path) -> None:
+    project_root = tmp_path / "project"
+    contrib_root = tmp_path / "contrib"
+    project_root.mkdir()
+    contrib_root.mkdir()
+    write_project(project_root)
+    write_contrib(contrib_root)
+
+    metadata = generate_metadata(project_root, contrib_root, allow_download=False)
+
+    assert metadata["component"] == "Splunk Distribution of OpenTelemetry Python"
+    assert metadata["version"] == "9.8.7"
+    assert [dependency["name"] for dependency in metadata["dependencies"][:2]] == [
+        "OpenTelemetry Python",
+        "OpenTelemetry Python Contrib",
+    ]
+    dependencies_by_name = {dependency["name"]: dependency for dependency in metadata["dependencies"]}
+    assert dependencies_by_name["OpenTelemetry Python"]["stability"] == "stable"
+    assert dependencies_by_name["OpenTelemetry Python Contrib"]["stability"] == "experimental"
+    assert dependencies_by_name["opentelemetry-instrumentation-system-metrics"]["stability"] == "experimental"
+    assert dependencies_by_name["wrapt"]["stability"] == "stable"
+    assert "property" in metadata["settings"][0]
+    assert "metrics" in metadata
+    assert metadata["resource_detectors"]
+    assert "dependencies" not in metadata["resource_detectors"][0]
+    assert any(item["keys"] == ["example"] for item in metadata["instrumentations"])
+    assert not any(item["keys"] == ["splunk-profiling"] for item in metadata["instrumentations"])
+    assert not any(item["keys"] == ["splunk-trace-response-header"] for item in metadata["instrumentations"])
+
+    yaml_text = dump_yaml(metadata)
+    assert "component: 'Splunk Distribution of OpenTelemetry Python'" in yaml_text
+    assert "resource_detectors:" in yaml_text