daemon: finished class variable type hinting for core.nodes

daemon/core/nodes/docker.py

@@ -2,7 +2,7 @@ import json
 import logging
 import os
 from tempfile import NamedTemporaryFile
-from typing import TYPE_CHECKING, Callable, Dict
+from typing import TYPE_CHECKING, Callable, Dict, Optional
 
 from core import utils
 from core.emulator.distributed import DistributedServer
@@ -17,10 +17,10 @@ if TYPE_CHECKING:
 
 class DockerClient:
     def __init__(self, name: str, image: str, run: Callable[..., str]) -> None:
-        self.name = name
-        self.image = image
-        self.run = run
-        self.pid = None
+        self.name: str = name
+        self.image: str = image
+        self.run: Callable[..., str] = run
+        self.pid: Optional[str] = None
 
     def create_container(self) -> str:
         self.run(
@@ -95,7 +95,7 @@ class DockerNode(CoreNode):
         """
         if image is None:
             image = "ubuntu"
-        self.image = image
+        self.image: str = image
         super().__init__(session, _id, name, nodedir, start, server)
 
     def create_node_net_client(self, use_ovs: bool) -> LinuxNetClient: