forked from jupyter-server/jupyter_server
-
Notifications
You must be signed in to change notification settings - Fork 0
/
manager.py
396 lines (332 loc) · 13 KB
/
manager.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
import importlib
import sys
import traceback
from tornado.gen import multi
from traitlets import Any, Bool, Dict, HasTraits, Instance, Unicode, default, observe
from traitlets import validate as validate_trait
from traitlets.config import LoggingConfigurable
from .config import ExtensionConfigManager
from .utils import (
ExtensionMetadataError,
ExtensionModuleNotFound,
get_loader,
get_metadata,
)
class ExtensionPoint(HasTraits):
"""A simple API for connecting to a Jupyter Server extension
point defined by metadata and importable from a Python package.
"""
_linked = Bool(False)
_app = Any(None, allow_none=True)
metadata = Dict()
@validate_trait("metadata")
def _valid_metadata(self, proposed):
metadata = proposed["value"]
# Verify that the metadata has a "name" key.
try:
self._module_name = metadata["module"]
except KeyError:
raise ExtensionMetadataError(
"There is no 'module' key in the extension's metadata packet."
)
try:
self._module = importlib.import_module(self._module_name)
except ImportError:
raise ExtensionModuleNotFound(
"The submodule '{}' could not be found. Are you "
"sure the extension is installed?".format(self._module_name)
)
# If the metadata includes an ExtensionApp, create an instance.
if "app" in metadata:
self._app = metadata["app"]()
return metadata
@property
def linked(self):
"""Has this extension point been linked to the server.
Will pull from ExtensionApp's trait, if this point
is an instance of ExtensionApp.
"""
if self.app:
return self.app._linked
return self._linked
@property
def app(self):
"""If the metadata includes an `app` field"""
return self._app
@property
def config(self):
"""Return any configuration provided by this extension point."""
if self.app:
return self.app._jupyter_server_config()
# At some point, we might want to add logic to load config from
# disk when extensions don't use ExtensionApp.
else:
return {}
@property
def module_name(self):
"""Name of the Python package module where the extension's
_load_jupyter_server_extension can be found.
"""
return self._module_name
@property
def name(self):
"""Name of the extension.
If it's not provided in the metadata, `name` is set
to the extensions' module name.
"""
if self.app:
return self.app.name
return self.metadata.get("name", self.module_name)
@property
def module(self):
"""The imported module (using importlib.import_module)"""
return self._module
def _get_linker(self):
if self.app:
linker = self.app._link_jupyter_server_extension
else:
linker = getattr(
self.module,
# Search for a _link_jupyter_extension
"_link_jupyter_server_extension",
# Otherwise return a dummy function.
lambda serverapp: None,
)
return linker
def _get_loader(self):
loc = self.app
if not loc:
loc = self.module
loader = get_loader(loc)
return loader
def validate(self):
"""Check that both a linker and loader exists."""
try:
self._get_linker()
self._get_loader()
except Exception:
return False
else:
return True
def link(self, serverapp):
"""Link the extension to a Jupyter ServerApp object.
This looks for a `_link_jupyter_server_extension` function
in the extension's module or ExtensionApp class.
"""
if not self.linked:
linker = self._get_linker()
linker(serverapp)
# Store this extension as already linked.
self._linked = True
def load(self, serverapp):
"""Load the extension in a Jupyter ServerApp object.
This looks for a `_load_jupyter_server_extension` function
in the extension's module or ExtensionApp class.
"""
loader = self._get_loader()
return loader(serverapp)
class ExtensionPackage(HasTraits):
"""An API for interfacing with a Jupyter Server extension package.
Usage:
ext_name = "my_extensions"
extpkg = ExtensionPackage(name=ext_name)
"""
name = Unicode(help="Name of the an importable Python package.")
enabled = Bool(False).tag(config=True)
def __init__(self, *args, **kwargs):
# Store extension points that have been linked.
self._linked_points = {}
super().__init__(*args, **kwargs)
_linked_points = {}
@validate_trait("name")
def _validate_name(self, proposed):
name = proposed["value"]
self._extension_points = {}
try:
self._module, self._metadata = get_metadata(name)
except ImportError:
raise ExtensionModuleNotFound(
"The module '{name}' could not be found. Are you "
"sure the extension is installed?".format(name=name)
)
# Create extension point interfaces for each extension path.
for m in self._metadata:
point = ExtensionPoint(metadata=m)
self._extension_points[point.name] = point
return name
@property
def module(self):
"""Extension metadata loaded from the extension package."""
return self._module
@property
def version(self):
"""Get the version of this package, if it's given. Otherwise, return an empty string"""
return getattr(self._module, "__version__", "")
@property
def metadata(self):
"""Extension metadata loaded from the extension package."""
return self._metadata
@property
def extension_points(self):
"""A dictionary of extension points."""
return self._extension_points
def validate(self):
"""Validate all extension points in this package."""
for extension in self.extension_points.values():
if not extension.validate():
return False
return True
def link_point(self, point_name, serverapp):
linked = self._linked_points.get(point_name, False)
if not linked:
point = self.extension_points[point_name]
point.link(serverapp)
def load_point(self, point_name, serverapp):
point = self.extension_points[point_name]
return point.load(serverapp)
def link_all_points(self, serverapp):
for point_name in self.extension_points:
self.link_point(point_name, serverapp)
def load_all_points(self, serverapp):
return [self.load_point(point_name, serverapp) for point_name in self.extension_points]
class ExtensionManager(LoggingConfigurable):
"""High level interface for findind, validating,
linking, loading, and managing Jupyter Server extensions.
Usage:
m = ExtensionManager(config_manager=...)
"""
config_manager = Instance(ExtensionConfigManager, allow_none=True)
serverapp = Any() # Use Any to avoid circular import of Instance(ServerApp)
@default("config_manager")
def _load_default_config_manager(self):
config_manager = ExtensionConfigManager()
self._load_config_manager(config_manager)
return config_manager
@observe("config_manager")
def _config_manager_changed(self, change):
if change.new:
self._load_config_manager(change.new)
# The `extensions` attribute provides a dictionary
# with extension (package) names mapped to their ExtensionPackage interface
# (see above). This manager simplifies the interaction between the
# ServerApp and the extensions being appended.
extensions = Dict(
help="""
Dictionary with extension package names as keys
and ExtensionPackage objects as values.
"""
)
@property
def sorted_extensions(self):
"""Returns an extensions dictionary, sorted alphabetically."""
return dict(sorted(self.extensions.items()))
# The `_linked_extensions` attribute tracks when each extension
# has been successfully linked to a ServerApp. This helps prevent
# extensions from being re-linked recursively unintentionally if another
# extension attempts to link extensions again.
linked_extensions = Dict(
help="""
Dictionary with extension names as keys
values are True if the extension is linked, False if not.
"""
)
@property
def extension_apps(self):
"""Return mapping of extension names and sets of ExtensionApp objects."""
return {
name: {point.app for point in extension.extension_points.values() if point.app}
for name, extension in self.extensions.items()
}
@property
def extension_points(self):
"""Return mapping of extension point names and ExtensionPoint objects."""
return {
name: point
for value in self.extensions.values()
for name, point in value.extension_points.items()
}
def from_config_manager(self, config_manager):
"""Add extensions found by an ExtensionConfigManager"""
# load triggered via config_manager trait observer
self.config_manager = config_manager
def _load_config_manager(self, config_manager):
"""Actually load our config manager"""
jpserver_extensions = config_manager.get_jpserver_extensions()
self.from_jpserver_extensions(jpserver_extensions)
def from_jpserver_extensions(self, jpserver_extensions):
"""Add extensions from 'jpserver_extensions'-like dictionary."""
for name, enabled in jpserver_extensions.items():
self.add_extension(name, enabled=enabled)
def add_extension(self, extension_name, enabled=False):
"""Try to add extension to manager, return True if successful.
Otherwise, return False.
"""
try:
extpkg = ExtensionPackage(name=extension_name, enabled=enabled)
self.extensions[extension_name] = extpkg
return True
# Raise a warning if the extension cannot be loaded.
except Exception as e:
if self.serverapp.reraise_server_extension_failures:
raise
self.log.warning(e)
return False
def link_extension(self, name):
linked = self.linked_extensions.get(name, False)
extension = self.extensions[name]
if not linked and extension.enabled:
try:
# Link extension and store links
extension.link_all_points(self.serverapp)
self.linked_extensions[name] = True
self.log.info("{name} | extension was successfully linked.".format(name=name))
except Exception as e:
if self.serverapp.reraise_server_extension_failures:
raise
self.log.warning(e)
def load_extension(self, name):
extension = self.extensions.get(name)
if extension.enabled:
try:
extension.load_all_points(self.serverapp)
except Exception as e:
if self.serverapp.reraise_server_extension_failures:
raise
self.log.debug("".join(traceback.format_exception(*sys.exc_info())))
self.log.warning(
"{name} | extension failed loading with message: {error}".format(
name=name, error=str(e)
)
)
else:
self.log.info("{name} | extension was successfully loaded.".format(name=name))
async def stop_extension(self, name, apps):
"""Call the shutdown hooks in the specified apps."""
for app in apps:
self.log.debug('{} | extension app "{}" stopping'.format(name, app.name))
await app.stop_extension()
self.log.debug('{} | extension app "{}" stopped'.format(name, app.name))
def link_all_extensions(self):
"""Link all enabled extensions
to an instance of ServerApp
"""
# Sort the extension names to enforce deterministic linking
# order.
for name in self.sorted_extensions.keys():
self.link_extension(name)
def load_all_extensions(self):
"""Load all enabled extensions and append them to
the parent ServerApp.
"""
# Sort the extension names to enforce deterministic loading
# order.
for name in self.sorted_extensions.keys():
self.load_extension(name)
async def stop_all_extensions(self):
"""Call the shutdown hooks in all extensions."""
await multi(
[
self.stop_extension(name, apps)
for name, apps in sorted(dict(self.extension_apps).items())
]
)