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