notebook/IPython/html/services/kernels/kernelmanager.py
2014-12-02 11:54:19 -08:00

124 lines
4.6 KiB
Python

"""A MultiKernelManager for use in the notebook webserver
- raises HTTPErrors
- creates REST API models
"""
# Copyright (c) IPython Development Team.
# Distributed under the terms of the Modified BSD License.
import os
from tornado import web
from IPython.kernel.multikernelmanager import MultiKernelManager
from IPython.utils.traitlets import List, Unicode, TraitError
from IPython.html.utils import to_os_path
from IPython.utils.py3compat import getcwd
class MappingKernelManager(MultiKernelManager):
"""A KernelManager that handles notebook mapping and HTTP error handling"""
def _kernel_manager_class_default(self):
return "IPython.kernel.ioloop.IOLoopKernelManager"
kernel_argv = List(Unicode)
root_dir = Unicode(config=True)
def _root_dir_default(self):
try:
return self.parent.notebook_dir
except AttributeError:
return getcwd()
def _root_dir_changed(self, name, old, new):
"""Do a bit of validation of the root dir."""
if not os.path.isabs(new):
# If we receive a non-absolute path, make it absolute.
self.root_dir = os.path.abspath(new)
return
if not os.path.exists(new) or not os.path.isdir(new):
raise TraitError("kernel root dir %r is not a directory" % new)
#-------------------------------------------------------------------------
# Methods for managing kernels and sessions
#-------------------------------------------------------------------------
def _handle_kernel_died(self, kernel_id):
"""notice that a kernel died"""
self.log.warn("Kernel %s died, removing from map.", kernel_id)
self.remove_kernel(kernel_id)
def cwd_for_path(self, path):
"""Turn API path into absolute OS path."""
os_path = to_os_path(path, self.root_dir)
# in the case of notebooks and kernels not being on the same filesystem,
# walk up to root_dir if the paths don't exist
while not os.path.isdir(os_path) and os_path != self.root_dir:
os_path = os.path.dirname(os_path)
return os_path
def start_kernel(self, kernel_id=None, path=None, kernel_name='python', **kwargs):
"""Start a kernel for a session and return its kernel_id.
Parameters
----------
kernel_id : uuid
The uuid to associate the new kernel with. If this
is not None, this kernel will be persistent whenever it is
requested.
path : API path
The API path (unicode, '/' delimited) for the cwd.
Will be transformed to an OS path relative to root_dir.
kernel_name : str
The name identifying which kernel spec to launch. This is ignored if
an existing kernel is returned, but it may be checked in the future.
"""
if kernel_id is None:
if path is not None:
kwargs['cwd'] = self.cwd_for_path(path)
kernel_id = super(MappingKernelManager, self).start_kernel(
kernel_name=kernel_name, **kwargs)
self.log.info("Kernel started: %s" % kernel_id)
self.log.debug("Kernel args: %r" % kwargs)
# register callback for failed auto-restart
self.add_restart_callback(kernel_id,
lambda : self._handle_kernel_died(kernel_id),
'dead',
)
else:
self._check_kernel_id(kernel_id)
self.log.info("Using existing kernel: %s" % kernel_id)
return kernel_id
def shutdown_kernel(self, kernel_id, now=False):
"""Shutdown a kernel by kernel_id"""
self._check_kernel_id(kernel_id)
super(MappingKernelManager, self).shutdown_kernel(kernel_id, now=now)
def kernel_model(self, kernel_id):
"""Return a dictionary of kernel information described in the
JSON standard model."""
self._check_kernel_id(kernel_id)
model = {"id":kernel_id,
"name": self._kernels[kernel_id].kernel_name}
return model
def list_kernels(self):
"""Returns a list of kernel_id's of kernels running."""
kernels = []
kernel_ids = super(MappingKernelManager, self).list_kernel_ids()
for kernel_id in kernel_ids:
model = self.kernel_model(kernel_id)
kernels.append(model)
return kernels
# override _check_kernel_id to raise 404 instead of KeyError
def _check_kernel_id(self, kernel_id):
"""Check a that a kernel_id exists and raise 404 if not."""
if kernel_id not in self:
raise web.HTTPError(404, u'Kernel does not exist: %s' % kernel_id)