diff --git a/inventory_provider/db/ims.py b/inventory_provider/db/ims.py
new file mode 100644
index 0000000000000000000000000000000000000000..c85c2d3c6f784615a93a540d58587b7643d1c125
--- /dev/null
+++ b/inventory_provider/db/ims.py
@@ -0,0 +1,198 @@
+import requests
+import time
+
+from enum import Enum
+
+
+# Navigation Properties
+
+# http://149.210.162.190:81/ImsVersions/4.19.9/html/2d27d509-77cb-537d-3ffa-796de7e82af8.htm # noqa
+NODE_PROPERTIES = {
+ 'equipment definition': 16,
+ 'management system': 128,
+ 'site': 256,
+ 'node city': 32768,
+ 'order': 67108864,
+ 'node country': 1073741824
+}
+# http://149.210.162.190:81/ImsVersions/4.19.9/html/347cb410-8c05-47bd-ceb0-d1dd05bf98a4.htm # noqa
+CITY_PROPERTIES = {
+ 'country': 8
+}
+# http://149.210.162.190:81/ImsVersions/4.19.9/html/347cb410-8c05-47bd-ceb0-d1dd05bf98a4.htm # noqa
+EQUIP_DEF_PROPERTIES = {
+ 'nodes': 4096
+}
+# http://149.210.162.190:81/ImsVersions/4.19.9/html/9c8d50f0-842c-5959-0fa6-14e1720669ec.htm # noqa
+SITE_PROPERTIES = {
+ 'aliases': 64,
+ 'city': 2,
+ 'country': 256
+}
+
+
+class InventoryStatus(Enum):
+ PLANNED = 1
+ READY_FOR_SERVICE = 2
+ IN_SERVICE = 3
+ MIGRATION = 4
+ OUT_OF_SERVICE = 6
+ READY_FOR_CEASURE = 7
+
+
+class IMSError(Exception):
+ pass
+
+
+class IMS(object):
+
+ TIMEOUT_THRESHOLD = 1200
+ NO_OF_ELEMENTS_PER_ITERATION = 50
+ PERMITTED_RECONNECT_ATTEMPTS = 3
+ LOGIN_PATH = '/login'
+ IMS_PATH = '/ims'
+
+ cache = {}
+ base_url = None
+ bearer_token = None
+ bearer_token_init_time = None
+ reconnect_attempts = 0
+
+ def __init__(self, base_url, username, password):
+ IMS.base_url = base_url
+ self.username = username
+ self.password = password
+
+ @classmethod
+ def _init_bearer_token(cls, username, password):
+ re_init_time = time.time()
+ if not cls.bearer_token or \
+ re_init_time - cls.bearer_token_init_time \
+ > cls.TIMEOUT_THRESHOLD:
+ IMS.reconnect_attempts = 0
+ else:
+ cls.reconnect_attempts += 1
+ if cls.reconnect_attempts > cls.PERMITTED_RECONNECT_ATTEMPTS:
+ raise IMSError('Too many reconnection attempts made')
+
+ response = requests.post(
+ IMS.base_url + IMS.LOGIN_PATH,
+ auth=(username, password))
+ response.raise_for_status()
+ cls.bearer_token_init_time = re_init_time
+ cls.bearer_token = response.json()
+
+ def _get_entity(
+ self,
+ url,
+ params=None,
+ navigation_properties=None,
+ use_cache=False):
+ url = f'{self.base_url + IMS.IMS_PATH}/{url}'
+ cache_key = url
+ if navigation_properties:
+ params = params if params else {}
+ params['navigationproperty'] = navigation_properties if isinstance(
+ navigation_properties, int) else sum(navigation_properties)
+
+ if use_cache:
+ if params:
+ s = '-'.join(
+ [f'{t}::{params[t]}'
+ for t in sorted(params)])
+ cache_key = f'{cache_key}::{s}'
+ entity = IMS.cache.get(cache_key, None)
+ if entity:
+ print('Got from cache') # Remove after demo
+ return entity
+
+ if not IMS.bearer_token:
+ self._init_bearer_token(self.username, self.password)
+
+ make_request = True
+ while make_request:
+ response = requests.get(
+ url,
+ headers={'Authorization': self.bearer_token},
+ params=params)
+ if response.status_code == requests.codes.unauthorized:
+ IMS._init_bearer_token(self.username, self.password)
+ else:
+ make_request = False
+
+ response.raise_for_status()
+ return_value = response.json()
+
+ if use_cache:
+ IMS.cache[cache_key] = return_value
+ return return_value
+
+ def get_entity_by_id(
+ self,
+ entity_type,
+ entity_id,
+ navigation_properties=None,
+ use_cache=False):
+
+ url = f'{entity_type}/{entity_id}'
+ return \
+ self._get_entity(url, None, navigation_properties, use_cache)
+
+ def get_entity_by_name(
+ self,
+ entity,
+ name,
+ navigation_properties=None,
+ use_cache=False):
+ url = f'{entity}/byname/{name}'
+ return self._get_entity(url, None, navigation_properties, use_cache)
+
+ def get_filtered_entities(
+ self,
+ entity,
+ filter_string,
+ navigation_properties=None,
+ use_cache=False):
+ more_to_come = True
+ start_entity = 0
+ while more_to_come:
+ params = {
+ 'paginatorStartElement': start_entity,
+ 'paginatorNumberOfElements': IMS.NO_OF_ELEMENTS_PER_ITERATION
+ }
+ url = f'{entity}/filtered/{filter_string}'
+ entities = self._get_entity(
+ url,
+ params,
+ navigation_properties,
+ use_cache)
+ more_to_come = False
+ if entities:
+ more_to_come = len(entities) >= IMS.NO_OF_ELEMENTS_PER_ITERATION
+ start_entity += IMS.NO_OF_ELEMENTS_PER_ITERATION
+ yield from entities
+
+ def get_all_entities(
+ self,
+ entity,
+ navigation_properties=None,
+ use_cache=False):
+ yield from self.get_filtered_entities(
+ entity,
+ 'Id <> 0',
+ navigation_properties,
+ use_cache)
+
+
+if __name__ == '__main__':
+ import sys
+ username = sys.argv[1]
+ password = sys.argv[2]
+ ims = IMS('http://83.97.94.128:81/api', username, password)
+ i = ims.get_entity_by_name(
+ 'Site',
+ 'London',
+ SITE_PROPERTIES.values())
+ print(i)
+
+