Custom MCP Server on Databricks Apps

from typing import Any from hatchling.builders.hooks.plugin.interface import BuildHookInterface from pathlib import Path import shutil class AppsBuildHook(BuildHookInterface): """Hook to create a Databricks Apps-compatible build. This hook is used to create a Databricks Apps-compatible build of the project. The following steps are performed: - Remove the ./.build folder if it exists. - Copy the artifact_path to the ./.build folder. - Write the name of the artifact to a requirements.txt file in the ./.build folder. - The resulting build directory is printed to the console. """ def finalize( self, version: str, build_data: dict[str, Any], artifact_path: str ) -> None: self.app.display_info( f"Running Databricks Apps build hook for project {self.metadata.name} in directory {Path.cwd()}" ) # remove the ./.build folder if it exists build_dir = Path(".build") self.app.display_info(f"Resulting build directory: {build_dir.absolute()}") if build_dir.exists(): self.app.display_info(f"Removing {build_dir}") shutil.rmtree(build_dir) self.app.display_info(f"Removed {build_dir}") else: self.app.display_info(f"{build_dir} does not exist, skipping removal") # copy the artifact_path to the ./.build folder build_dir.mkdir(exist_ok=True) self.app.display_info(f"Copying {artifact_path} to {build_dir}") shutil.copy(artifact_path, build_dir) # write the name of the artifact to a requirements.txt file in the ./.build folder requirements_file = build_dir / "requirements.txt" requirements_file.write_text(Path(artifact_path).name, encoding="utf-8") app_file = Path("app.yaml") if app_file.exists(): self.app.display_info(f"Copying {app_file} to {build_dir}") shutil.copy(app_file, build_dir) else: self.app.display_info(f"{app_file} does not exist, skipping copy") # Copy the resources folder for WAF measures resources_dir = Path("resources") if resources_dir.exists(): self.app.display_info(f"Copying {resources_dir} to {build_dir}") shutil.copytree(resources_dir, build_dir / "resources") else: self.app.display_info(f"{resources_dir} does not exist, skipping copy") self.app.display_info( f"Apps-compatible build written to {build_dir.absolute()}" )