Multiple changes:

Common:
- reorganized Database API to enable extension of Context API with entities (e.g. Service)
- solved minor bugs in Database API

Context and Device services:
- rearranged services and unit tests according to mentioned Context API changes

Service service:
- initial release (under development, this is just a backup of code)

src/service/service/__main__.py

+import logging, os, signal, sys, threading
+from prometheus_client import start_http_server
+from common.database.Factory import get_database
+from service.service.ServiceService import ServiceService
+from service.Config import GRPC_SERVICE_PORT, GRPC_MAX_WORKERS, GRPC_GRACE_PERIOD, LOG_LEVEL, METRICS_PORT
+
+terminate = threading.Event()
+logger = None
+
+def signal_handler(signal, frame):
+    global terminate, logger
+    logger.warning('Terminate signal received')
+    terminate.set()
+
+def main():
+    global terminate, logger
+
+    service_port = os.environ.get('SERVICESERVICE_SERVICE_PORT_GRPC', GRPC_SERVICE_PORT)
+    max_workers  = os.environ.get('MAX_WORKERS',  GRPC_MAX_WORKERS )
+    grace_period = os.environ.get('GRACE_PERIOD', GRPC_GRACE_PERIOD)
+    log_level    = os.environ.get('LOG_LEVEL',    LOG_LEVEL   )
+    metrics_port = os.environ.get('METRICS_PORT', METRICS_PORT)
+
+    logging.basicConfig(level=log_level)
+    logger = logging.getLogger(__name__)
+
+    signal.signal(signal.SIGINT,  signal_handler)
+    signal.signal(signal.SIGTERM, signal_handler)
+
+    logger.info('Starting...')
+
+    # Start metrics server
+    start_http_server(metrics_port)
+
+    # Get database instance
+    database = get_database()
+
+    # Starting service service
+    service = ServiceService(database, port=service_port, max_workers=max_workers, grace_period=grace_period)
+    service.start()
+
+    # Wait for Ctrl+C or termination signal
+    while not terminate.wait(0.1): pass
+
+    logger.info('Terminating...')
+    service.stop()
+
+    logger.info('Bye')
+    return(0)
+
+if __name__ == '__main__':
+    sys.exit(main())

src/service/tests/test_unitary.py

+import logging, pytest
+from common.database.Factory import get_database, DatabaseEngineEnum
+from service.Config import GRPC_SERVICE_PORT, GRPC_MAX_WORKERS, GRPC_GRACE_PERIOD
+from service.client.ServiceClient import ServiceClient
+from service.service.ServiceService import ServiceService
+
+LOGGER = logging.getLogger(__name__)
+LOGGER.setLevel(logging.DEBUG)
+
+@pytest.fixture(scope='session')
+def service_database():
+    _database = get_database(engine=DatabaseEngineEnum.INMEMORY)
+    return _database
+
+@pytest.fixture(scope='session')
+def service_service(service_database):
+    _service = ServiceService(
+        service_database, port=GRPC_SERVICE_PORT, max_workers=GRPC_MAX_WORKERS, grace_period=GRPC_GRACE_PERIOD)
+    _service.start()
+    yield _service
+    _service.stop()
+
+@pytest.fixture(scope='session')
+def service_client(service_service):
+    _client = ServiceClient(address='127.0.0.1', port=GRPC_SERVICE_PORT)
+    yield _client
+    _client.close()