sdk/python/arvados/api.py

   1 import httplib2
   2 import json
   3 import logging
   4 import os
   5 import re
   6 import types
   7
   8 import apiclient
   9 import apiclient.discovery
  10 import config
  11 import errors
  12 import util
  13
  14 services = {}
  15
  16 class CredentialsFromEnv(object):
  17     @staticmethod
  18     def http_request(self, uri, **kwargs):
  19         from httplib import BadStatusLine
  20         if 'headers' not in kwargs:
  21             kwargs['headers'] = {}
  22
  23         if config.get("ARVADOS_EXTERNAL_CLIENT", "") == "true":
  24             kwargs['headers']['X-External-Client'] = '1'
  25
  26         kwargs['headers']['Authorization'] = 'OAuth2 %s' % config.get('ARVADOS_API_TOKEN', 'ARVADOS_API_TOKEN_not_set')
  27         try:
  28             return self.orig_http_request(uri, **kwargs)
  29         except BadStatusLine:
  30             # This is how httplib tells us that it tried to reuse an
  31             # existing connection but it was already closed by the
  32             # server. In that case, yes, we would like to retry.
  33             # Unfortunately, we are not absolutely certain that the
  34             # previous call did not succeed, so this is slightly
  35             # risky.
  36             return self.orig_http_request(uri, **kwargs)
  37     def authorize(self, http):
  38         http.orig_http_request = http.request
  39         http.request = types.MethodType(self.http_request, http)
  40         return http
  41
  42 # Monkey patch discovery._cast() so objects and arrays get serialized
  43 # with json.dumps() instead of str().
  44 _cast_orig = apiclient.discovery._cast
  45 def _cast_objects_too(value, schema_type):
  46     global _cast_orig
  47     if (type(value) != type('') and
  48         (schema_type == 'object' or schema_type == 'array')):
  49         return json.dumps(value)
  50     else:
  51         return _cast_orig(value, schema_type)
  52 apiclient.discovery._cast = _cast_objects_too
  53
  54 def http_cache(data_type):
  55     path = os.environ['HOME'] + '/.cache/arvados/' + data_type
  56     try:
  57         util.mkdir_dash_p(path)
  58     except OSError:
  59         path = None
  60     return path
  61
  62 def api(version=None, cache=True):
  63     global services
  64
  65     if 'ARVADOS_DEBUG' in config.settings():
  66         logging.basicConfig(level=logging.DEBUG)
  67
  68     if not cache or not services.get(version):
  69         apiVersion = version
  70         if not version:
  71             apiVersion = 'v1'
  72             logging.info("Using default API version. " +
  73                          "Call arvados.api('%s') instead." %
  74                          apiVersion)
  75         if 'ARVADOS_API_HOST' not in config.settings():
  76             raise Exception("ARVADOS_API_HOST is not set. Aborting.")
  77         url = ('https://%s/discovery/v1/apis/{api}/{apiVersion}/rest' %
  78                config.get('ARVADOS_API_HOST'))
  79         credentials = CredentialsFromEnv()
  80
  81         # Use system's CA certificates (if we find them) instead of httplib2's
  82         ca_certs = '/etc/ssl/certs/ca-certificates.crt'
  83         if not os.path.exists(ca_certs):
  84             ca_certs = None             # use httplib2 default
  85
  86         http = httplib2.Http(ca_certs=ca_certs,
  87                              cache=(http_cache('discovery') if cache else None))
  88         http = credentials.authorize(http)
  89         if re.match(r'(?i)^(true|1|yes)$',
  90                     config.get('ARVADOS_API_HOST_INSECURE', 'no')):
  91             http.disable_ssl_certificate_validation=True
  92         services[version] = apiclient.discovery.build(
  93             'arvados', apiVersion, http=http, discoveryServiceUrl=url)
  94         http.cache = None
  95     return services[version]