Update jupyterhub_config.py

jupyterhub_config.py

@@ -13,8 +13,10 @@ c = get_config()  # noqa: F821
 # Spawn single-user servers as Docker containers
 c.JupyterHub.spawner_class = "dockerspawner.DockerSpawner"
 
-# Spawn containers from this image
-c.DockerSpawner.image = os.environ["DOCKER_NOTEBOOK_IMAGE"]
+
+
+c.DockerSpawner.image = os.environ.get("DOCKER_NOTEBOOK_IMAGE", "jupyter/base-notebook:latest")
+
 
 # Connect containers to this Docker network
 network_name = os.environ["DOCKER_NETWORK_NAME"]