| 1 | #!/usr/bin/env python3 |
| 2 | # |
| 3 | # Copyright (C) 2022 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 4 | # |
| 5 | # SPDX-License-Identifier: GPL-2.0-only |
| 6 | |
| 7 | import abc |
| 8 | import random |
| 9 | import string |
| 10 | import pathlib |
| 11 | import enum |
| 12 | from typing import Optional, Type, Union, List |
| 13 | |
| 14 | """ |
| 15 | Defines an abstract interface to control LTTng tracing. |
| 16 | |
| 17 | The various control concepts are defined by this module. You can use them with a |
| 18 | Controller to interact with a session daemon. |
| 19 | |
| 20 | This interface is not comprehensive; it currently provides a subset of the |
| 21 | control functionality that is used by tests. |
| 22 | """ |
| 23 | |
| 24 | |
| 25 | def _generate_random_string(length: int) -> str: |
| 26 | return "".join( |
| 27 | random.choice(string.ascii_lowercase + string.digits) for _ in range(length) |
| 28 | ) |
| 29 | |
| 30 | |
| 31 | class ContextType(abc.ABC): |
| 32 | """Base class representing a tracing context field.""" |
| 33 | |
| 34 | pass |
| 35 | |
| 36 | |
| 37 | class VpidContextType(ContextType): |
| 38 | """Application's virtual process id.""" |
| 39 | |
| 40 | pass |
| 41 | |
| 42 | |
| 43 | class VuidContextType(ContextType): |
| 44 | """Application's virtual user id.""" |
| 45 | |
| 46 | pass |
| 47 | |
| 48 | |
| 49 | class VgidContextType(ContextType): |
| 50 | """Application's virtual group id.""" |
| 51 | |
| 52 | pass |
| 53 | |
| 54 | |
| 55 | class JavaApplicationContextType(ContextType): |
| 56 | """A java application-specific context field is a piece of state which the application provides.""" |
| 57 | |
| 58 | def __init__(self, retriever_name: str, field_name: str): |
| 59 | self._retriever_name: str = retriever_name |
| 60 | self._field_name: str = field_name |
| 61 | |
| 62 | @property |
| 63 | def retriever_name(self) -> str: |
| 64 | return self._retriever_name |
| 65 | |
| 66 | @property |
| 67 | def field_name(self) -> str: |
| 68 | return self._field_name |
| 69 | |
| 70 | |
| 71 | class TracingDomain(enum.Enum): |
| 72 | """Tracing domain.""" |
| 73 | |
| 74 | User = enum.auto(), "User space tracing domain" |
| 75 | Kernel = enum.auto(), "Linux kernel tracing domain." |
| 76 | Log4j = enum.auto(), "Log4j tracing back-end." |
| 77 | JUL = enum.auto(), "Java Util Logging tracing back-end." |
| 78 | Python = enum.auto(), "Python logging module tracing back-end." |
| 79 | |
| 80 | |
| 81 | class EventRule(abc.ABC): |
| 82 | """Event rule base class, see LTTNG-EVENT-RULE(7).""" |
| 83 | |
| 84 | pass |
| 85 | |
| 86 | |
| 87 | class LogLevelRule: |
| 88 | pass |
| 89 | |
| 90 | |
| 91 | class LogLevelRuleAsSevereAs(LogLevelRule): |
| 92 | def __init__(self, level: int): |
| 93 | self._level = level |
| 94 | |
| 95 | @property |
| 96 | def level(self) -> int: |
| 97 | return self._level |
| 98 | |
| 99 | |
| 100 | class LogLevelRuleExactly(LogLevelRule): |
| 101 | def __init__(self, level: int): |
| 102 | self._level = level |
| 103 | |
| 104 | @property |
| 105 | def level(self) -> int: |
| 106 | return self._level |
| 107 | |
| 108 | |
| 109 | class TracepointEventRule(EventRule): |
| 110 | def __init__( |
| 111 | self, |
| 112 | name_pattern: Optional[str] = None, |
| 113 | filter_expression: Optional[str] = None, |
| 114 | log_level_rule: Optional[LogLevelRule] = None, |
| 115 | name_pattern_exclusions: Optional[List[str]] = None, |
| 116 | ): |
| 117 | self._name_pattern: Optional[str] = name_pattern |
| 118 | self._filter_expression: Optional[str] = filter_expression |
| 119 | self._log_level_rule: Optional[LogLevelRule] = log_level_rule |
| 120 | self._name_pattern_exclusions: Optional[List[str]] = name_pattern_exclusions |
| 121 | |
| 122 | @property |
| 123 | def name_pattern(self) -> Optional[str]: |
| 124 | return self._name_pattern |
| 125 | |
| 126 | @property |
| 127 | def filter_expression(self) -> Optional[str]: |
| 128 | return self._filter_expression |
| 129 | |
| 130 | @property |
| 131 | def log_level_rule(self) -> Optional[LogLevelRule]: |
| 132 | return self._log_level_rule |
| 133 | |
| 134 | @property |
| 135 | def name_pattern_exclusions(self) -> Optional[List[str]]: |
| 136 | return self._name_pattern_exclusions |
| 137 | |
| 138 | |
| 139 | class UserTracepointEventRule(TracepointEventRule): |
| 140 | def __init__( |
| 141 | self, |
| 142 | name_pattern: Optional[str] = None, |
| 143 | filter_expression: Optional[str] = None, |
| 144 | log_level_rule: Optional[LogLevelRule] = None, |
| 145 | name_pattern_exclusions: Optional[List[str]] = None, |
| 146 | ): |
| 147 | TracepointEventRule.__init__(**locals()) |
| 148 | |
| 149 | |
| 150 | class KernelTracepointEventRule(TracepointEventRule): |
| 151 | def __init__( |
| 152 | self, |
| 153 | name_pattern: Optional[str] = None, |
| 154 | filter_expression: Optional[str] = None, |
| 155 | log_level_rule: Optional[LogLevelRule] = None, |
| 156 | name_pattern_exclusions: Optional[List[str]] = None, |
| 157 | ): |
| 158 | TracepointEventRule.__init__(**locals()) |
| 159 | |
| 160 | |
| 161 | class Channel(abc.ABC): |
| 162 | """ |
| 163 | A channel is an object which is responsible for a set of ring buffers. It is |
| 164 | associated to a domain and |
| 165 | """ |
| 166 | |
| 167 | @staticmethod |
| 168 | def _generate_name() -> str: |
| 169 | return "channel_{random_id}".format(random_id=_generate_random_string(8)) |
| 170 | |
| 171 | @abc.abstractmethod |
| 172 | def add_context(self, context_type: ContextType) -> None: |
| 173 | pass |
| 174 | |
| 175 | @property |
| 176 | @abc.abstractmethod |
| 177 | def domain(self) -> TracingDomain: |
| 178 | pass |
| 179 | |
| 180 | @property |
| 181 | @abc.abstractmethod |
| 182 | def name(self) -> str: |
| 183 | pass |
| 184 | |
| 185 | @abc.abstractmethod |
| 186 | def add_recording_rule(self, rule: Type[EventRule]) -> None: |
| 187 | pass |
| 188 | |
| 189 | |
| 190 | class SessionOutputLocation(abc.ABC): |
| 191 | pass |
| 192 | |
| 193 | |
| 194 | class LocalSessionOutputLocation(SessionOutputLocation): |
| 195 | def __init__(self, trace_path: pathlib.Path): |
| 196 | self._path = trace_path |
| 197 | |
| 198 | @property |
| 199 | def path(self) -> pathlib.Path: |
| 200 | return self._path |
| 201 | |
| 202 | |
| 203 | class ProcessAttributeTracker(abc.ABC): |
| 204 | """ |
| 205 | Process attribute tracker used to filter before the evaluation of event |
| 206 | rules. |
| 207 | |
| 208 | Note that this interface is currently limited as it doesn't allow changing |
| 209 | the tracking policy. For instance, it is not possible to set the tracking |
| 210 | policy back to "all" once it has transitioned to "include set". |
| 211 | """ |
| 212 | |
| 213 | class TrackingPolicy(enum.Enum): |
| 214 | INCLUDE_ALL = ( |
| 215 | enum.auto(), |
| 216 | """ |
| 217 | Track all possible process attribute value of a given type (i.e. no filtering). |
| 218 | This is the default state of a process attribute tracker. |
| 219 | """, |
| 220 | ) |
| 221 | EXCLUDE_ALL = ( |
| 222 | enum.auto(), |
| 223 | "Exclude all possible process attribute values of a given type.", |
| 224 | ) |
| 225 | INCLUDE_SET = enum.auto(), "Track a set of specific process attribute values." |
| 226 | |
| 227 | def __init__(self, policy: TrackingPolicy): |
| 228 | self._policy = policy |
| 229 | |
| 230 | @property |
| 231 | def tracking_policy(self) -> TrackingPolicy: |
| 232 | return self._policy |
| 233 | |
| 234 | |
| 235 | class ProcessIDProcessAttributeTracker(ProcessAttributeTracker): |
| 236 | @abc.abstractmethod |
| 237 | def track(self, pid: int) -> None: |
| 238 | pass |
| 239 | |
| 240 | @abc.abstractmethod |
| 241 | def untrack(self, pid: int) -> None: |
| 242 | pass |
| 243 | |
| 244 | |
| 245 | class VirtualProcessIDProcessAttributeTracker(ProcessAttributeTracker): |
| 246 | @abc.abstractmethod |
| 247 | def track(self, vpid: int) -> None: |
| 248 | pass |
| 249 | |
| 250 | @abc.abstractmethod |
| 251 | def untrack(self, vpid: int) -> None: |
| 252 | pass |
| 253 | |
| 254 | |
| 255 | class UserIDProcessAttributeTracker(ProcessAttributeTracker): |
| 256 | @abc.abstractmethod |
| 257 | def track(self, uid: Union[int, str]) -> None: |
| 258 | pass |
| 259 | |
| 260 | @abc.abstractmethod |
| 261 | def untrack(self, uid: Union[int, str]) -> None: |
| 262 | pass |
| 263 | |
| 264 | |
| 265 | class VirtualUserIDProcessAttributeTracker(ProcessAttributeTracker): |
| 266 | @abc.abstractmethod |
| 267 | def track(self, vuid: Union[int, str]) -> None: |
| 268 | pass |
| 269 | |
| 270 | @abc.abstractmethod |
| 271 | def untrack(self, vuid: Union[int, str]) -> None: |
| 272 | pass |
| 273 | |
| 274 | |
| 275 | class GroupIDProcessAttributeTracker(ProcessAttributeTracker): |
| 276 | @abc.abstractmethod |
| 277 | def track(self, gid: Union[int, str]) -> None: |
| 278 | pass |
| 279 | |
| 280 | @abc.abstractmethod |
| 281 | def untrack(self, gid: Union[int, str]) -> None: |
| 282 | pass |
| 283 | |
| 284 | |
| 285 | class VirtualGroupIDProcessAttributeTracker(ProcessAttributeTracker): |
| 286 | @abc.abstractmethod |
| 287 | def track(self, vgid: Union[int, str]) -> None: |
| 288 | pass |
| 289 | |
| 290 | @abc.abstractmethod |
| 291 | def untrack(self, vgid: Union[int, str]) -> None: |
| 292 | pass |
| 293 | |
| 294 | |
| 295 | class Session(abc.ABC): |
| 296 | @staticmethod |
| 297 | def _generate_name() -> str: |
| 298 | return "session_{random_id}".format(random_id=_generate_random_string(8)) |
| 299 | |
| 300 | @property |
| 301 | @abc.abstractmethod |
| 302 | def name(self) -> str: |
| 303 | pass |
| 304 | |
| 305 | @property |
| 306 | @abc.abstractmethod |
| 307 | def output(self) -> Optional[Type[SessionOutputLocation]]: |
| 308 | pass |
| 309 | |
| 310 | @abc.abstractmethod |
| 311 | def add_channel( |
| 312 | self, domain: TracingDomain, channel_name: Optional[str] = None |
| 313 | ) -> Channel: |
| 314 | """Add a channel with default attributes to the session.""" |
| 315 | pass |
| 316 | |
| 317 | @abc.abstractmethod |
| 318 | def start(self) -> None: |
| 319 | pass |
| 320 | |
| 321 | @abc.abstractmethod |
| 322 | def stop(self) -> None: |
| 323 | pass |
| 324 | |
| 325 | @abc.abstractmethod |
| 326 | def destroy(self) -> None: |
| 327 | pass |
| 328 | |
| 329 | @abc.abstractproperty |
| 330 | def kernel_pid_process_attribute_tracker( |
| 331 | self, |
| 332 | ) -> Type[ProcessIDProcessAttributeTracker]: |
| 333 | raise NotImplementedError |
| 334 | |
| 335 | @abc.abstractproperty |
| 336 | def kernel_vpid_process_attribute_tracker( |
| 337 | self, |
| 338 | ) -> Type[VirtualProcessIDProcessAttributeTracker]: |
| 339 | raise NotImplementedError |
| 340 | |
| 341 | @abc.abstractproperty |
| 342 | def user_vpid_process_attribute_tracker( |
| 343 | self, |
| 344 | ) -> Type[VirtualProcessIDProcessAttributeTracker]: |
| 345 | raise NotImplementedError |
| 346 | |
| 347 | @abc.abstractproperty |
| 348 | def kernel_gid_process_attribute_tracker( |
| 349 | self, |
| 350 | ) -> Type[GroupIDProcessAttributeTracker]: |
| 351 | raise NotImplementedError |
| 352 | |
| 353 | @abc.abstractproperty |
| 354 | def kernel_vgid_process_attribute_tracker( |
| 355 | self, |
| 356 | ) -> Type[VirtualGroupIDProcessAttributeTracker]: |
| 357 | raise NotImplementedError |
| 358 | |
| 359 | @abc.abstractproperty |
| 360 | def user_vgid_process_attribute_tracker( |
| 361 | self, |
| 362 | ) -> Type[VirtualGroupIDProcessAttributeTracker]: |
| 363 | raise NotImplementedError |
| 364 | |
| 365 | @abc.abstractproperty |
| 366 | def kernel_uid_process_attribute_tracker( |
| 367 | self, |
| 368 | ) -> Type[UserIDProcessAttributeTracker]: |
| 369 | raise NotImplementedError |
| 370 | |
| 371 | @abc.abstractproperty |
| 372 | def kernel_vuid_process_attribute_tracker( |
| 373 | self, |
| 374 | ) -> Type[VirtualUserIDProcessAttributeTracker]: |
| 375 | raise NotImplementedError |
| 376 | |
| 377 | @abc.abstractproperty |
| 378 | def user_vuid_process_attribute_tracker( |
| 379 | self, |
| 380 | ) -> Type[VirtualUserIDProcessAttributeTracker]: |
| 381 | raise NotImplementedError |
| 382 | |
| 383 | |
| 384 | class ControlException(RuntimeError): |
| 385 | """Base type for exceptions thrown by a controller.""" |
| 386 | |
| 387 | def __init__(self, msg: str): |
| 388 | super().__init__(msg) |
| 389 | |
| 390 | |
| 391 | class Controller(abc.ABC): |
| 392 | """ |
| 393 | Interface of a top-level control interface. A control interface can be, for |
| 394 | example, the LTTng client or a wrapper around liblttng-ctl. It is used to |
| 395 | create and manage top-level objects of a session daemon instance. |
| 396 | """ |
| 397 | |
| 398 | @abc.abstractmethod |
| 399 | def create_session( |
| 400 | self, name: Optional[str] = None, output: Optional[SessionOutputLocation] = None |
| 401 | ) -> Session: |
| 402 | """ |
| 403 | Create a session with an output. Don't specify an output |
| 404 | to create a session without an output. |
| 405 | """ |
| 406 | pass |