feat: add cdf dev function serve command

cognite_toolkit/_cdf_tk/apps/__init__.py

@@ -2,6 +2,7 @@
 from ._core_app import CoreApp
 from ._data_app import DataApp
 from ._dev_app import DevApp
+from ._dev_function_app import DevFunctionApp
 from ._download_app import DownloadApp
 from ._dump_app import DumpApp
 from ._import_app import ImportApp
@@ -20,6 +21,7 @@
     "CoreApp",
     "DataApp",
     "DevApp",
+    "DevFunctionApp",
     "DownloadApp",
     "DumpApp",
     "ImportApp",

cognite_toolkit/_cdf_tk/apps/_dev_app.py

@@ -11,6 +11,7 @@
 from cognite_toolkit._cdf_tk.feature_flags import FeatureFlag, Flags
 from cognite_toolkit._cdf_tk.utils.auth import EnvironmentVariables
 
+from ._dev_function_app import DevFunctionApp
 from ._run import RunApp
 
 CDF_TOML = CDFToml.load(Path.cwd())
@@ -21,6 +22,7 @@ def __init__(self, *args: Any, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
         self.callback(invoke_without_command=True)(self.main)
         self.add_typer(RunApp(*args, **kwargs), name="run")
+        self.add_typer(DevFunctionApp(*args, **kwargs), name="function")
         if FeatureFlag.is_enabled(Flags.CREATE):
             self.command("create")(self.create)
 

cognite_toolkit/_cdf_tk/apps/_dev_function_app.py

@@ -0,0 +1,45 @@
+from pathlib import Path
+from typing import Annotated, Any
+
+import typer
+from rich import print
+
+from cognite_toolkit._cdf_tk.commands import ServeFunctionCommand
+
+
+class DevFunctionApp(typer.Typer):
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        super().__init__(*args, **kwargs)
+        self.callback(invoke_without_command=True)(self.main)
+        self.command("serve")(self.serve)
+
+    @staticmethod
+    def main(ctx: typer.Context) -> None:
+        """Commands for function app development."""
+        if ctx.invoked_subcommand is None:
+            print("Use [bold yellow]cdf dev function --help[/] for more information.")
+
+    @staticmethod
+    def serve(
+        path: Annotated[
+            Path | None,
+            typer.Argument(help="Path to the directory containing handler.py. If omitted, discovers and prompts."),
+        ] = None,
+        host: Annotated[str, typer.Option("--host", help="Host to bind to")] = "127.0.0.1",
+        port: Annotated[int, typer.Option("--port", help="Port to bind to")] = 8000,
+        reload: Annotated[bool, typer.Option("--reload/--no-reload", help="Enable auto-reload on code changes")] = True,
+        log_level: Annotated[
+            str,
+            typer.Option("--log-level", help="Log level for the server"),
+        ] = "info",
+    ) -> None:
+        """Start a local development server for testing a function app handler.
+
+        Loads your handler.py and starts a uvicorn dev server with Swagger UI.
+
+        Example:
+            cdf dev function serve my_function/
+            cdf dev function serve . --port 3000 --no-reload
+        """
+        cmd = ServeFunctionCommand(client=None, skip_tracking=True)
+        cmd.run(lambda: cmd.serve(path, host, port, reload, log_level))

cognite_toolkit/_cdf_tk/commands/__init__.py

@@ -21,6 +21,7 @@
 from .repo import RepoCommand
 from .resources import ResourcesCommand
 from .run import RunFunctionCommand, RunTransformationCommand, RunWorkflowCommand
+from .serve import ServeFunctionCommand
 
 __all__ = [
     "AboutCommand",
@@ -48,5 +49,6 @@
     "RunFunctionCommand",
     "RunTransformationCommand",
     "RunWorkflowCommand",
+    "ServeFunctionCommand",
     "UploadCommand",
 ]