diff options
Diffstat (limited to 'cdsapi/api.py')
| -rw-r--r-- | cdsapi/api.py | 379 |
1 files changed, 379 insertions, 0 deletions
diff --git a/cdsapi/api.py b/cdsapi/api.py new file mode 100644 index 0000000..88a3a8c --- /dev/null +++ b/cdsapi/api.py @@ -0,0 +1,379 @@ +# (C) Copyright 2018 ECMWF. +# +# This software is licensed under the terms of the Apache Licence Version 2.0 +# which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. +# In applying this licence, ECMWF does not waive the privileges and immunities +# granted to it by virtue of its status as an intergovernmental organisation nor +# does it submit to any jurisdiction. + +from __future__ import absolute_import, division, print_function, unicode_literals + +import json +import time +import os +import logging + +import requests + + +def bytes_to_string(n): + u = ['', 'K', 'M', 'G', 'T', 'P'] + i = 0 + while n >= 1024: + n /= 1024.0 + i += 1 + return '%g%s' % (int(n * 10 + 0.5) / 10.0, u[i]) + + +def read_config(path): + config = {} + with open(path) as f: + for l in f.readlines(): + if ':' in l: + k, v = l.strip().split(':', 1) + if k in ('url', 'key', 'verify'): + config[k] = v.strip() + return config + + +class Result(object): + + def __init__(self, client, reply): + + self.reply = reply + + self._url = client.url + + self.session = client.session + self.robust = client.robust + self.verify = client.verify + self.cleanup = client.delete + + self.debug = client.debug + self.info = client.info + self.warning = client.warning + self.error = client.error + + self._deleted = False + + def _download(self, url, size, target): + + if target is None: + target = url.split('/')[-1] + + self.info("Downloading %s to %s (%s)", url, target, bytes_to_string(size)) + start = time.time() + + r = self.robust(requests.get)(url, stream=True, verify=self.verify) + try: + r.raise_for_status() + + total = 0 + with open(target, 'wb') as f: + for chunk in r.iter_content(chunk_size=1024): + if chunk: + f.write(chunk) + total += len(chunk) + finally: + r.close() + + if total != size: + raise Exception("Download failed: downloaded %s byte(s) out of %s" % (total, size)) + + elapsed = time.time() - start + if elapsed: + self.info("Download rate %s/s", bytes_to_string(size / elapsed)) + + return target + + def download(self, target=None): + return self._download(self.location, + self.content_length, + target) + + @property + def content_length(self): + return int(self.reply['content_length']) + + @property + def location(self): + return self.reply['location'] + + @property + def content_type(self): + return self.reply['content_type'] + + def __repr__(self): + return "Result(content_length=%s,content_type=%s,location=%s)" % (self.content_length, + self.content_type, + self.location) + + def check(self): + self.debug("HEAD %s", self.reply['location']) + metadata = self.robust(self.session.head)(self.reply['location'], + verify=self.verify) + metadata.raise_for_status() + self.debug(metadata.headers) + return metadata + + def delete(self): + + if self._deleted: + return + + if 'request_id' in self.reply: + rid = self.reply['request_id'] + + task_url = '%s/tasks/%s' % (self._url, rid) + self.debug("DELETE %s", task_url) + + delete = self.session.delete(task_url, verify=self.verify) + self.debug("DELETE returns %s %s", delete.status_code, delete.reason) + + try: + delete.raise_for_status() + except Exception: + self.warning("DELETE %s returns %s %s", + task_url, delete.status_code, delete.reason) + + self._deleted = True + + def __del__(self): + try: + if self.cleanup: + self.delete() + except Exception as e: + print(e) + + +class Client(object): + + logger = logging.getLogger('cdsapi') + + def __init__(self, + url=os.environ.get('CDSAPI_URL'), + key=os.environ.get('CDSAPI_KEY'), + quiet=False, + debug=False, + verify=None, + timeout=None, + full_stack=False, + delete=True, + retry_max=500, + sleep_max=120, + info_callback=None, + warning_callback=None, + error_callback=None, + debug_callback=None, + ): + + if not quiet: + + if debug: + level = logging.DEBUG + else: + level = logging.INFO + + logging.basicConfig(level=level, + format='%(asctime)s %(levelname)s %(message)s') + + dotrc = os.environ.get('CDSAPI_RC', os.path.expanduser('~/.cdsapirc')) + + if url is None or key is None: + if os.path.exists(dotrc): + config = read_config(dotrc) + + if key is None: + key = config.get('key') + + if url is None: + url = config.get('url') + + if verify is None: + verify = int(config.get('verify', 1)) + + if url is None or key is None or key is None: + raise Exception('Missing/incomplete configuration file: %s' % (dotrc)) + + self.url = url + self.key = key + + self.quiet = quiet + self.verify = True if verify else False + self.timeout = timeout + self.sleep_max = sleep_max + self.retry_max = retry_max + self.full_stack = full_stack + self.delete = delete + self.last_state = None + + self.debug_callback = debug_callback + self.warning_callback = warning_callback + self.info_callback = info_callback + self.error_callback = error_callback + + self.session = requests.Session() + self.session.auth = tuple(self.key.split(':', 2)) + + self.debug("CDSAPI %s", dict(url=self.url, + key=self.key, + quiet=self.quiet, + verify=self.verify, + timeout=self.timeout, + sleep_max=self.sleep_max, + retry_max=self.retry_max, + full_stack=self.full_stack, + delete=self.delete + )) + + def retrieve(self, name, request, target=None): + result = self._api('%s/resources/%s' % (self.url, name), request) + if target is not None: + result.download(target) + return result + + def identity(self): + return self._api('%s/resources' % (self.url,), {}) + + def _api(self, url, request): + + session = self.session + + self.info("Sending request to %s", url) + self.debug("POST %s %s", url, json.dumps(request)) + + result = self.robust(session.post)(url, json=request, verify=self.verify) + reply = None + + try: + result.raise_for_status() + reply = result.json() + except Exception: + + if reply is None: + try: + reply = result.json() + except Exception: + reply = dict(message=result.text) + + self.debug(json.dumps(reply)) + + if 'message' in reply: + error = reply['message'] + + if 'context' in reply and 'required_terms' in reply['context']: + e = [error] + for t in reply['context']['required_terms']: + e.append("To access this resource, you first need to accept the terms" + "of '%s' at %s" % (t['title'], t['url'])) + error = '. '.join(e) + raise Exception(error) + else: + raise + + sleep = 1 + start = time.time() + + while True: + + self.debug("REPLY %s", reply) + + if reply['state'] != self.last_state: + self.info("Request is %s" % (reply['state'],)) + self.last_state = reply['state'] + + if reply['state'] == 'completed': + self.debug("Done") + return Result(self, reply) + + if reply['state'] in ('queued', 'running'): + rid = reply['request_id'] + + if self.timeout and (time.time() - start > self.timeout): + raise Exception('TIMEOUT') + + self.debug("Request ID is %s, sleep %s", rid, sleep) + time.sleep(sleep) + sleep *= 1.5 + if sleep > self.sleep_max: + sleep = self.sleep_max + + task_url = '%s/tasks/%s' % (self.url, rid) + self.debug("GET %s", task_url) + + result = self.robust(session.get)(task_url, verify=self.verify) + result.raise_for_status() + reply = result.json() + continue + + if reply['state'] in ('failed',): + self.error("Message: %s", reply['error'].get('message')) + self.error("Reason: %s", reply['error'].get('reason')) + for n in reply.get('error', {}).get('context', {}).get('traceback', '').split('\n'): + if n.strip() == '' and not self.full_stack: + break + self.error(" %s", n) + raise Exception("%s. %s." % (reply['error'].get('message'), reply['error'].get('reason'))) + + raise Exception('Unknown API state [%s]' % (reply['state'],)) + + def info(self, *args, **kwargs): + if self.info_callback: + self.info_callback(*args, **kwargs) + else: + self.logger.info(*args, **kwargs) + + def warning(self, *args, **kwargs): + if self.warning_callback: + self.warning_callback(*args, **kwargs) + else: + self.logger.warning(*args, **kwargs) + + def error(self, *args, **kwargs): + if self.error_callback: + self.error_callback(*args, **kwargs) + else: + self.logger.error(*args, **kwargs) + + def debug(self, *args, **kwargs): + if self.debug_callback: + self.debug_callback(*args, **kwargs) + else: + self.logger.debug(*args, **kwargs) + + def robust(self, call): + + def retriable(code, reason): + + if code in [requests.codes.internal_server_error, + requests.codes.bad_gateway, + requests.codes.service_unavailable, + requests.codes.gateway_timeout, + requests.codes.too_many_requests, + requests.codes.request_timeout]: + return True + + return False + + def wrapped(*args, **kwargs): + tries = 0 + while tries < self.retry_max: + try: + r = call(*args, **kwargs) + except requests.exceptions.ConnectionError as e: + r = None + self.warning("Recovering from connection error [%s], attemps %s of %s", + e, tries, self.retry_max) + + if r is not None: + if not retriable(r.status_code, r.reason): + return r + self.warning("Recovering from HTTP error [%s %s], attemps %s of %s", + r.status_code, r.reason, tries, self.retry_max) + + tries += 1 + + self.warning("Retrying in %s seconds", self.sleep_max) + time.sleep(self.sleep_max) + + return wrapped |