| """An application to launch a kernel by name in a local subprocess.""" |
|
|
| import os |
| import signal |
| import typing as t |
| import uuid |
|
|
| from jupyter_core.application import JupyterApp, base_flags |
| from tornado.ioloop import IOLoop |
| from traitlets import Unicode |
|
|
| from . import __version__ |
| from .kernelspec import NATIVE_KERNEL_NAME, KernelSpecManager |
| from .manager import KernelManager |
|
|
|
|
| class KernelApp(JupyterApp): |
| """Launch a kernel by name in a local subprocess.""" |
|
|
| version = __version__ |
| description = "Run a kernel locally in a subprocess" |
|
|
| classes = [KernelManager, KernelSpecManager] |
|
|
| aliases = { |
| "kernel": "KernelApp.kernel_name", |
| "ip": "KernelManager.ip", |
| } |
| flags = {"debug": base_flags["debug"]} |
|
|
| kernel_name = Unicode(NATIVE_KERNEL_NAME, help="The name of a kernel type to start").tag( |
| config=True |
| ) |
|
|
| def initialize(self, argv: t.Union[str, t.Sequence[str], None] = None) -> None: |
| """Initialize the application.""" |
| super().initialize(argv) |
|
|
| cf_basename = "kernel-%s.json" % uuid.uuid4() |
| self.config.setdefault("KernelManager", {}).setdefault( |
| "connection_file", os.path.join(self.runtime_dir, cf_basename) |
| ) |
| self.km = KernelManager(kernel_name=self.kernel_name, config=self.config) |
|
|
| self.loop = IOLoop.current() |
| self.loop.add_callback(self._record_started) |
|
|
| def setup_signals(self) -> None: |
| """Shutdown on SIGTERM or SIGINT (Ctrl-C)""" |
| if os.name == "nt": |
| return |
|
|
| def shutdown_handler(signo: int, frame: t.Any) -> None: |
| self.loop.add_callback_from_signal(self.shutdown, signo) |
|
|
| for sig in [signal.SIGTERM, signal.SIGINT]: |
| signal.signal(sig, shutdown_handler) |
|
|
| def shutdown(self, signo: int) -> None: |
| """Shut down the application.""" |
| self.log.info("Shutting down on signal %d", signo) |
| self.km.shutdown_kernel() |
| self.loop.stop() |
|
|
| def log_connection_info(self) -> None: |
| """Log the connection info for the kernel.""" |
| cf = self.km.connection_file |
| self.log.info("Connection file: %s", cf) |
| self.log.info("To connect a client: --existing %s", os.path.basename(cf)) |
|
|
| def _record_started(self) -> None: |
| """For tests, create a file to indicate that we've started |
| |
| Do not rely on this except in our own tests! |
| """ |
| fn = os.environ.get("JUPYTER_CLIENT_TEST_RECORD_STARTUP_PRIVATE") |
| if fn is not None: |
| with open(fn, "wb"): |
| pass |
|
|
| def start(self) -> None: |
| """Start the application.""" |
| self.log.info("Starting kernel %r", self.kernel_name) |
| try: |
| self.km.start_kernel() |
| self.log_connection_info() |
| self.setup_signals() |
| self.loop.start() |
| finally: |
| self.km.cleanup_resources() |
|
|
|
|
| main = KernelApp.launch_instance |
|
|
