Add pip_tools

velocitas_lib/pip_tools.py

@@ -0,0 +1,51 @@
+# Copyright (c) 2023-2024 Contributors to the Eclipse Foundation
+#
+# This program and the accompanying materials are made available under the
+# terms of the Apache License, Version 2.0 which is available at
+# https://www.apache.org/licenses/LICENSE-2.0.
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+"""Provides methods and functions to download and install dependencies."""
+
+import os
+import subprocess
+import sys
+
+ENV_VAR_VELOCITAS_OFFLINE = "VELOCITAS_OFFLINE"
+
+
+def is_velocitas_offline_variant() -> bool:
+    """Require and return an environment variable.
+
+    Args:
+        name (str): The name of the variable.
+
+    Raises:
+        ValueError: In case the environment variable is not set.
+
+    Returns:
+        str: The value of the variable.
+    """
+    offline_var = os.getenv(ENV_VAR_VELOCITAS_OFFLINE)
+    if not offline_var or offline_var == "false":
+        return False
+    return True
+
+
+def pip(args: list[str]) -> None:
+    """Invoke the pip process with the given arguments."""
+    subprocess.check_call([sys.executable, "-m", "pip", *args])
+
+
+def install_requirements(requirements_path: str) -> None:
+    """Install all required Python packages for the model generator and
+    VSpec download."""
+    if not is_velocitas_offline_variant():
+        pip(["install", "-r", requirements_path])