2 """arvados_docker.cleaner - Remove unused Docker images from compute nodes
5 python3 -m arvados_docker.cleaner --quota 50G
20 SUFFIX_SIZES = {suffix: 1024 ** exp for exp, suffix in enumerate('kmgt', 1)}
22 logger = logging.getLogger('arvados_docker.cleaner')
24 def return_when_docker_not_found(result=None):
25 # If the decorated function raises a 404 error from Docker, return
27 def docker_not_found_decorator(orig_func):
28 @functools.wraps(orig_func)
29 def docker_not_found_wrapper(*args, **kwargs):
31 return orig_func(*args, **kwargs)
32 except docker.errors.APIError as error:
33 if error.response.status_code != 404:
36 return docker_not_found_wrapper
37 return docker_not_found_decorator
40 def __init__(self, image_hash):
41 self.docker_id = image_hash['Id']
42 self.size = image_hash['VirtualSize']
45 def used_at(self, use_time):
46 self.last_used = max(self.last_used, use_time)
50 def __init__(self, target_size):
51 self.target_size = target_size
53 self.container_image_map = {}
56 def from_daemon(cls, target_size, docker_client):
57 images = cls(target_size)
58 for image in docker_client.images():
59 images.add_image(image)
62 def add_image(self, image_hash):
63 image = DockerImage(image_hash)
64 self.images[image.docker_id] = image
65 logger.debug("Registered image %s", image.docker_id)
67 def del_image(self, image_id):
68 if image_id in self.images:
69 del self.images[image_id]
70 self.container_image_map = {
72 for cid, cid_image in self.container_image_map.items()
73 if cid_image != image_id}
74 logger.debug("Unregistered image %s", image_id)
76 def has_image(self, image_id):
77 return image_id in self.images
79 def add_user(self, container_hash, use_time):
80 image_id = container_hash['Image']
81 if image_id in self.images:
82 self.container_image_map[container_hash['Id']] = image_id
83 self.images[image_id].used_at(use_time)
84 logger.debug("Registered container %s using image %s",
85 container_hash['Id'], image_id)
87 def end_user(self, cid):
88 self.container_image_map.pop(cid, None)
89 logger.debug("Unregistered container %s", cid)
91 def should_delete(self):
94 # Build a list of images, ordered by use time.
95 lru_images = list(self.images.values())
96 lru_images.sort(key=lambda image: image.last_used)
97 # Make sure we don't delete any images in use, or if there are
98 # none, the most recently used image.
99 if self.container_image_map:
100 keep_ids = set(self.container_image_map.values())
102 keep_ids = {lru_images[-1].docker_id}
103 space_left = (self.target_size - sum(self.images[image_id].size
104 for image_id in keep_ids))
105 # Go through the list most recently used first, and note which
106 # images can be saved with the space allotted.
107 for image in reversed(lru_images):
108 if (image.docker_id not in keep_ids) and (image.size <= space_left):
109 keep_ids.add(image.docker_id)
110 space_left -= image.size
111 # Yield the Docker IDs of any image we don't want to save, least
112 # recently used first.
113 for image in lru_images:
114 if image.docker_id not in keep_ids:
115 yield image.docker_id
118 class DockerEventHandlers:
119 # This class maps Docker event types to the names of methods that should
120 # receive those events.
122 self.handler_names = collections.defaultdict(list)
124 def on(self, *status_names):
125 def register_handler(handler_method):
126 for status in status_names:
127 self.handler_names[status].append(handler_method.__name__)
128 return handler_method
129 return register_handler
131 def for_event(self, status):
132 return iter(self.handler_names[status])
135 result = self.__class__()
136 result.handler_names = copy.deepcopy(self.handler_names)
140 class DockerEventListener:
141 # To use this class, define event_handlers as an instance of
142 # DockerEventHandlers. Call run() to iterate over events and call the
143 # handler methods as they come in.
146 def __init__(self, events):
150 for event in self.events:
151 event = json.loads(event.decode(self.ENCODING))
152 if event.get('Type', 'container') != 'container':
154 for method_name in self.event_handlers.for_event(event.get('status')):
155 getattr(self, method_name)(event)
158 class DockerImageUseRecorder(DockerEventListener):
159 event_handlers = DockerEventHandlers()
161 def __init__(self, images, docker_client, events):
163 self.docker_client = docker_client
164 super().__init__(events)
166 @event_handlers.on('create')
167 @return_when_docker_not_found()
168 def load_container(self, event):
169 container_hash = self.docker_client.inspect_container(event['id'])
170 self.new_container(event, container_hash)
172 def new_container(self, event, container_hash):
173 self.images.add_user(container_hash, event['time'])
175 @event_handlers.on('destroy')
176 def container_stopped(self, event):
177 self.images.end_user(event['id'])
180 class DockerImageCleaner(DockerImageUseRecorder):
181 event_handlers = DockerImageUseRecorder.event_handlers.copy()
183 def __init__(self, images, docker_client, events, remove_containers_onexit=False):
184 super().__init__(images, docker_client, events)
185 self.logged_unknown = set()
186 self.remove_containers_onexit = remove_containers_onexit
188 def new_container(self, event, container_hash):
189 container_image_id = container_hash['Image']
190 if not self.images.has_image(container_image_id):
191 image_hash = self.docker_client.inspect_image(container_image_id)
192 self.images.add_image(image_hash)
193 return super().new_container(event, container_hash)
195 def _remove_container(self, cid):
197 self.docker_client.remove_container(cid, v=True)
198 except docker.errors.APIError as error:
199 logger.warning("Failed to remove container %s: %s", cid, error)
201 logger.info("Removed container %s", cid)
203 @event_handlers.on('die')
204 def clean_container(self, event=None):
205 if self.remove_containers_onexit:
206 self._remove_container(event['id'])
208 def check_stopped_containers(self, remove=False):
209 logger.info("Checking for stopped containers")
210 for c in self.docker_client.containers(filters={'status': 'exited'}):
211 logger.info("Container %s %s", c['Id'], c['Status'])
212 if c['Status'][:6] != 'Exited':
213 logger.error("Unexpected status %s for container %s",
214 c['Status'], c['Id'])
216 self._remove_container(c['Id'])
218 @event_handlers.on('destroy')
219 def clean_images(self, event=None):
220 for image_id in self.images.should_delete():
222 self.docker_client.remove_image(image_id)
223 except docker.errors.APIError as error:
224 logger.warning("Failed to remove image %s: %s", image_id, error)
226 logger.info("Removed image %s", image_id)
227 self.images.del_image(image_id)
229 @event_handlers.on('destroy')
230 def log_unknown_images(self, event):
231 unknown_ids = {image['Id'] for image in self.docker_client.images()
232 if not self.images.has_image(image['Id'])}
233 for image_id in (unknown_ids - self.logged_unknown):
234 logger.info("Image %s is loaded but unused, so it won't be cleaned",
236 self.logged_unknown = unknown_ids
239 def human_size(size_str):
240 size_str = size_str.lower().rstrip('b')
241 multiplier = SUFFIX_SIZES.get(size_str[-1])
242 if multiplier is None:
245 size_str = size_str[:-1]
246 return int(size_str) * multiplier
248 def load_config(arguments):
249 args = parse_arguments(arguments)
251 config = default_config()
252 with open(args.config, 'r') as f:
253 config.update(json.load(f))
255 configargs = vars(args).copy()
256 configargs.pop('config')
257 config.update({k: v for k, v in configargs.items() if v})
259 if isinstance(config['Quota'], str):
260 config['Quota'] = human_size(config['Quota'])
264 def default_config():
267 'RemoveStoppedContainers': 'always',
271 def parse_arguments(arguments):
272 class Formatter(argparse.ArgumentDefaultsHelpFormatter,
273 argparse.RawDescriptionHelpFormatter):
275 parser = argparse.ArgumentParser(
276 prog="arvados_docker.cleaner",
277 description="clean old Docker images from Arvados compute nodes",
278 epilog="Example config file:\n\n{}".format(
279 json.dumps(default_config(), indent=4)),
280 formatter_class=Formatter,
283 '--config', action='store', type=str, default='/etc/arvados/dockercleaner/config.json',
284 help="configuration file")
286 deprecated = " (DEPRECATED -- use config file instead)"
288 '--quota', action='store', type=human_size, dest='Quota',
289 help="space allowance for Docker images, suffixed with K/M/G/T" + deprecated)
291 '--remove-stopped-containers', type=str, default='always', dest='RemoveStoppedContainers',
292 choices=['never', 'onexit', 'always'],
293 help="""when to remove stopped containers (default: always, i.e., remove
294 stopped containers found at startup, and remove containers as
295 soon as they exit)""" + deprecated)
297 '--verbose', '-v', action='count', default=0, dest='Verbose',
298 help="log more information" + deprecated)
300 return parser.parse_args(arguments)
302 def setup_logging(config):
303 log_handler = logging.StreamHandler()
304 log_handler.setFormatter(logging.Formatter(
305 '%(asctime)s %(name)s[%(process)d] %(levelname)s: %(message)s',
306 '%Y-%m-%d %H:%M:%S'))
307 logger.addHandler(log_handler)
308 logger.setLevel(logging.ERROR - (10 * config['Verbose']))
310 def run(config, docker_client):
311 start_time = int(time.time())
312 logger.debug("Loading Docker activity through present")
313 images = DockerImages.from_daemon(config['Quota'], docker_client)
314 use_recorder = DockerImageUseRecorder(
315 images, docker_client, docker_client.events(since=1, until=start_time))
317 cleaner = DockerImageCleaner(
318 images, docker_client, docker_client.events(since=start_time),
319 remove_containers_onexit=config['RemoveStoppedContainers'] != 'never')
320 cleaner.check_stopped_containers(
321 remove=config['RemoveStoppedContainers'] == 'always')
322 logger.info("Checking image quota at startup")
323 cleaner.clean_images()
324 logger.info("Listening for docker events")
327 def main(arguments=sys.argv[1:]):
328 config = load_config(arguments)
329 setup_logging(config)
331 run(config, docker.Client(version='1.14'))
332 except KeyboardInterrupt:
335 if __name__ == '__main__':