Fill in the macro implementation

sentry_streams_k8s/pyproject.toml

@@ -12,6 +12,7 @@ dependencies = [
     "jsonschema>=4.23.0",
     "requests>=2.32.3",
     "sentry-infra-tools>=1.24.0",
+    "sentry-streams",
     "pyyaml>=6.0.2",
 ]
 
@@ -21,14 +22,16 @@ dev = [
     "pre-commit>=4.1.0",
     "pytest>=8.3.4",
     "responses>=0.25.6",
+    "types-jsonschema>=4.23.0",
+    "types-pyyaml>=6.0.2",
     "types-requests>=2.32.0",
 ]
 
 [tool.setuptools.packages.find]
 where = ["."]
 
 [tool.setuptools.package-data]
-sentry_streams_k8s = ["py.typed"]
+sentry_streams_k8s = ["py.typed", "templates/deployment.yaml", "templates/container.yaml"]
 
 [tool.pytest.ini_options]
 minversion = "6.0"

sentry_streams_k8s/sentry_streams_k8s/__init__.py

@@ -0,0 +1,4 @@
+from sentry_streams_k8s.merge import TypeMismatchError
+from sentry_streams_k8s.pipeline_step import PipelineStep, PipelineStepContext
+
+__all__ = ["PipelineStep", "PipelineStepContext", "TypeMismatchError"]

sentry_streams_k8s/sentry_streams_k8s/merge.py

@@ -0,0 +1,68 @@
+"""Dictionary merging utilities for Kubernetes manifest templates."""
+
+import copy
+from typing import Any
+
+
+class TypeMismatchError(TypeError):
+    """Raised when attempting to merge incompatible types in deepmerge."""
+
+    pass
+
+
+def deepmerge(base: dict[str, Any], override: dict[str, Any]) -> dict[str, Any]:
+    """
+    Deep merge two dictionaries with specific semantics for Kubernetes manifests.
+
+    Merge semantics:
+    - Simple types (str, int, bool, None): override replaces base
+    - Dictionaries: recursively merge
+    - Lists: concatenate (append override elements to base)
+    - Type mismatches (e.g., dict + list, dict + str): raises TypeMismatchError
+
+    Returns:
+        A new dictionary with merged values (base and override are not mutated)
+
+    Raises:
+        TypeMismatchError: When attempting to merge incompatible types
+            (e.g., trying to merge a dict with a list, or a list with a string)
+
+    Examples:
+        >>> base = {"a": 1, "b": {"c": 2}}
+        >>> override = {"b": {"d": 3}, "e": 4}
+        >>> deepmerge(base, override)
+        {'a': 1, 'b': {'c': 2, 'd': 3}, 'e': 4}
+
+        >>> base = {"volumes": [{"name": "vol1"}]}
+        >>> override = {"volumes": [{"name": "vol2"}]}
+        >>> deepmerge(base, override)
+        {'volumes': [{'name': 'vol1'}, {'name': 'vol2'}]}
+
+        >>> base = {"key": {"nested": "value"}}
+        >>> override = {"key": "string"}
+        >>> deepmerge(base, override)
+        Traceback (most recent call last):
+            ...
+        TypeMismatchError: Cannot merge key 'key': base type is dict but override type is str
+    """
+    result = copy.deepcopy(base)
+
+    for key, override_value in override.items():
+        if key not in result:
+            result[key] = copy.deepcopy(override_value)
+        else:
+            base_value = result[key]
+
+            # Both base and override have this key
+            if isinstance(base_value, dict) and isinstance(override_value, dict):
+                result[key] = deepmerge(base_value, override_value)
+            elif isinstance(base_value, list) and isinstance(override_value, list):
+                result[key] = base_value + copy.deepcopy(override_value)
+            elif type(base_value) is not type(override_value):
+                raise TypeMismatchError(
+                    f"Cannot merge key '{key}': base type is {type(base_value)} but override type is {type(override_value)}"
+                )
+            else:
+                result[key] = copy.deepcopy(override_value)
+
+    return result