Throw build error on conflicting requirements (#621)

* Throw build error if requirements conflict.

* Bump RC.

* Added comment.

Author: squidarth

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "truss"
-version = "0.6.5rc1"
+version = "0.6.5rc2"
 description = "A seamless bridge from model development to model delivery"
 license = "MIT"
 readme = "README.md"

truss/contexts/image_builder/serving_image_builder.py

@@ -358,10 +358,8 @@ def copy_into_build_dir(from_path: Path, path_in_build_dir: str):
             )
 
         # Copy base TrussServer requirements if supplied custom base image
+        base_truss_server_reqs_filepath = SERVER_CODE_DIR / REQUIREMENTS_TXT_FILENAME
         if config.base_image:
-            base_truss_server_reqs_filepath = (
-                SERVER_CODE_DIR / REQUIREMENTS_TXT_FILENAME
-            )
             copy_into_build_dir(
                 base_truss_server_reqs_filepath, BASE_SERVER_REQUIREMENTS_TXT_FILENAME
             )
@@ -374,7 +372,22 @@ def copy_into_build_dir(from_path: Path, path_in_build_dir: str):
         if should_install_server_requirements:
             copy_into_build_dir(server_reqs_filepath, SERVER_REQUIREMENTS_TXT_FILENAME)
 
-        (build_dir / REQUIREMENTS_TXT_FILENAME).write_text(spec.requirements_txt)
+        with open(base_truss_server_reqs_filepath, "r") as f:
+            base_server_requirements = f.read()
+
+        # If the user has provided python requirements,
+        # append the truss server requirements, so that any conflicts
+        # are detected and cause a build failure. If there are no
+        # requirements provided, we just pass an empty string,
+        # as there's no need to install anything.
+        user_provided_python_requirements = (
+            base_server_requirements + spec.requirements_txt
+            if spec.requirements
+            else ""
+        )
+        (build_dir / REQUIREMENTS_TXT_FILENAME).write_text(
+            user_provided_python_requirements
+        )
         (build_dir / SYSTEM_PACKAGES_TXT_FILENAME).write_text(spec.system_packages_txt)
 
         self._render_dockerfile(

truss/tests/contexts/image_builder/test_serving_image_builder.py

@@ -31,3 +31,21 @@ def filter_empty_lines(lines):
         gen_docker_lines = filter_empty_lines(gen_docker_lines)
         server_docker_lines = filter_empty_lines(server_docker_lines)
         assert gen_docker_lines == server_docker_lines
+
+
+def test_requirements_setup_in_build_dir(custom_model_truss_dir):
+    th = TrussHandle(custom_model_truss_dir)
+    th.add_python_requirement("numpy")
+    builder_context = ServingImageBuilderContext
+    image_builder = builder_context.run(th.spec.truss_dir)
+
+    with TemporaryDirectory() as tmp_dir:
+        tmp_path = Path(tmp_dir)
+        image_builder.prepare_image_build_dir(tmp_path)
+        with open(tmp_path / "requirements.txt", "r") as f:
+            requirements_content = f.read()
+
+        with open(f"{BASE_DIR}/../../../templates/server/requirements.txt", "r") as f:
+            base_requirements_content = f.read()
+
+        assert requirements_content == base_requirements_content + "numpy\n"