Add host_config_options to allow configuration of DockerTask for GPU …

…resources (#3234)

* feat: expose host config options to DockerTask

* docs: add docstrings with links to docker api

luigi/contrib/docker_runner.py

@@ -77,8 +77,24 @@ def command(self):
     def name(self):
         return None
 
+    @property
+    def host_config_options(self):
+        '''
+        Override this to specify host_config options like gpu requests or shm
+        size e.g. `{"device_requests": [docker.types.DeviceRequest(count=1, capabilities=[["gpu"]])]}`
+
+        See https://docker-py.readthedocs.io/en/stable/api.html#docker.api.container.ContainerApiMixin.create_host_config
+        '''
+        return {}
+
     @property
     def container_options(self):
+        '''
+        Override this to specify container options like user or ports e.g.
+        `{"user": f"{os.getuid()}:{os.getgid()}"}`
+
+        See https://docker-py.readthedocs.io/en/stable/api.html#docker.api.container.ContainerApiMixin.create_container
+        '''
         return {}
 
     @property
@@ -192,7 +208,8 @@ def run(self):
                          % (self._image, self.command, self._binds))
 
             host_config = self._client.create_host_config(binds=self._binds,
-                                                          network_mode=self.network_mode)
+                                                          network_mode=self.network_mode,
+                                                          **self.host_config_options)
 
             container = self._client.create_container(self._image,
                                                       command=self.command,