[docker] Handle the uid at docker level rather than inside container.

beat/core/execution/docker.py

@@ -222,6 +222,7 @@ class DockerExecutor(RemoteExecutor):
         #----- (If necessary) Instantiate the docker container that provide the databases
 
         databases_container = None
+        datasets_uid =  self.data.pop('datasets_uid', None)
 
         if len(self.databases) > 0:
 
@@ -270,6 +271,7 @@ class DockerExecutor(RemoteExecutor):
                 cmd.insert(1, '--debug')
 
             databases_container = self.host.create_container(databases_environment, cmd)
+            databases_container.uid = datasets_uid
 
             # Specify the volumes to mount inside the container
             databases_container.add_volume(databases_configuration_path, '/beat/prefix')
@@ -319,6 +321,7 @@ class DockerExecutor(RemoteExecutor):
 
         # Creation of the container
         algorithm_container = self.host.create_container(processing_environment, cmd)
+        algorithm_container.uid = datasets_uid
 
         # Volumes
         algorithm_container.add_volume(configuration_path, '/beat/prefix')