local-binder-local-hub: easier testing of auth and non-standard Docker

- Forward the `DOCKER_HOST` env-var from JupyterHub to BinderHub/repo2docker to make it easier to test when the docker socket is in a non-standard location (e..g Podman)
- Add an `AUTHENTICATOR=dummy` env-var to make it easier to test BinderHub authentication

testing/local-binder-local-hub/README.md

@@ -17,3 +17,8 @@ Run JupyterHub in one terminal
 
 BinderHub will be running as a managed JupyterHub service, go to http://localhost:8000
 and you should be redirected to BinderHub.
+
+If you want to test BinderHub with dummy authentication:
+
+    export AUTHENTICATOR=dummy
+    jupyterhub --config=jupyterhub_config.py

testing/local-binder-local-hub/binderhub_config.py

@@ -42,3 +42,6 @@
 # JUPYTERHUB_BASE_URL may not include the host
 # c.BinderHub.hub_url = os.getenv('JUPYTERHUB_BASE_URL')
 c.BinderHub.hub_url = os.getenv("JUPYTERHUB_EXTERNAL_URL") or f"http://{hostip}:8000"
+
+if os.getenv("AUTH_ENABLED") == "1":
+    c.BinderHub.auth_enabled = True

testing/local-binder-local-hub/jupyterhub_config.py

@@ -30,7 +30,20 @@ class LocalContainerSpawner(BinderSpawnerMixin, DockerSpawner):
 
 c.Application.log_level = "DEBUG"
 c.Spawner.debug = True
-c.JupyterHub.authenticator_class = "null"
+c.JupyterHub.authenticator_class = os.getenv("AUTHENTICATOR", "null")
+
+auth_enabled = c.JupyterHub.authenticator_class != "null"
+if auth_enabled:
+    c.JupyterHub.load_roles = [
+        {
+            "name": "user",
+            "description": "Standard user privileges",
+            "scopes": [
+                "self",
+                "access:services!service=binder",
+            ],
+        }
+    ]
 
 c.JupyterHub.hub_ip = "0.0.0.0"
 c.JupyterHub.hub_connect_ip = hostip
@@ -39,9 +52,11 @@ class LocalContainerSpawner(BinderSpawnerMixin, DockerSpawner):
 binderhub_config = os.path.join(os.path.dirname(__file__), "binderhub_config.py")
 
 binderhub_environment = {}
-for env_var in ["JUPYTERHUB_EXTERNAL_URL", "GITHUB_ACCESS_TOKEN"]:
+for env_var in ["JUPYTERHUB_EXTERNAL_URL", "GITHUB_ACCESS_TOKEN", "DOCKER_HOST"]:
     if os.getenv(env_var) is not None:
         binderhub_environment[env_var] = os.getenv(env_var)
+    if auth_enabled:
+        binderhub_environment["AUTH_ENABLED"] = "1"
 c.JupyterHub.services = [
     {
         "name": binderhub_service_name,