[execution][docker] Refactor handling of database container

Explicitly set the name of the container and retrieve its
address with the new Host API.

beat/core/execution/docker.py

@@ -279,9 +279,11 @@ class DockerExecutor(RemoteExecutor):
             if logger.getEffectiveLevel() <= logging.DEBUG:
                 cmd.insert(1, '--debug')
 
+            databases_container_name = "beat_db_%s" % utils.id_generator()
             databases_container = self.host.create_container(databases_environment, cmd)
             databases_container.uid = datasets_uid
             databases_container.network_name = network_name
+            databases_container.set_name(databases_container_name)
 
             # Specify the volumes to mount inside the container
             databases_container.add_volume(databases_configuration_path, '/beat/prefix')
@@ -308,13 +310,7 @@ class DockerExecutor(RemoteExecutor):
                     cmd = [x if not x.startswith('0.0.0.0:') else '0.0.0.0:%d' % database_port for x in cmd]
                     databases_container.command = cmd
 
-            database_ip = self.host.ip
-            client = docker.from_env()
-            for container in client.containers.list():
-                newtwork_settings = container.attrs['NetworkSettings']
-                for port, mapping in newtwork_settings['Ports'].items():
-                    if port.startswith('%d' % database_port):
-                        database_ip = newtwork_settings['Networks'][network_name]['IPAddress']
+            database_ip = self.host.get_ipaddress(databases_container)
 
 
         #----- Instantiate the algorithm container