core: dump some debug info in /data/environment

tensorboard/backend/event_processing/data_provider.py

@@ -41,6 +41,9 @@ def __init__(self, multiplexer, logdir):
         self._multiplexer = multiplexer
         self._logdir = logdir
 
+    def __str__(self):
+        return "MultiplexerDataProvider(logdir=%r)" % self._logdir
+
     def _validate_context(self, ctx):
         if type(ctx).__name__ != "RequestContext":
             raise TypeError("ctx must be a RequestContext; got: %r" % (ctx,))

tensorboard/data/grpc_provider.py

@@ -46,6 +46,9 @@ def __init__(self, addr, stub):
         self._addr = addr
         self._stub = stub
 
+    def __str__(self):
+        return "GrpcDataProvider(addr=%r)" % self._addr
+
     def data_location(self, ctx, *, experiment_id):
         req = data_provider_pb2.GetExperimentRequest()
         req.experiment_id = experiment_id

tensorboard/default.py

@@ -71,7 +71,7 @@ class ExperimentalNpmiPlugin(
 # Ordering matters. The order in which these lines appear determines the
 # ordering of tabs in TensorBoard's GUI.
 _PLUGINS = [
-    core_plugin.CorePluginLoader,
+    core_plugin.CorePluginLoader(include_debug_info=True),
     scalars_plugin.ScalarsPlugin,
     custom_scalars_plugin.CustomScalarsPlugin,
     images_plugin.ImagesPlugin,

tensorboard/http_api.md

@@ -161,12 +161,22 @@ Example response:
 
 Returns environment in which the TensorBoard app is running.
 
+The `version` is the Pip version string of the TensorBoard server, like
+`"2.4.0a0"`.
+
+The `window_title` is the value of the `--window_title` flag.
+
 The `data_location` is a user-readable string describing the source from which
 TensorBoard is reading data, such as a directory on disk.
 
+The response may also include a `debug` field, with information that may be
+useful for humans inspecting the system. The contents and structure of `debug`
+are subject to change.
+
 Example response:
 
     {
+      "version": "2.4.0",
       "window_title": "Custom Name",
       "data_location": "/Users/tbuser/tensorboard_data/"
     }

tensorboard/plugins/core/BUILD

@@ -11,6 +11,7 @@ py_library(
     srcs_version = "PY3",
     deps = [
         "//tensorboard:plugin_util",
+        "//tensorboard:version",
         "//tensorboard/backend:http_util",
         "//tensorboard/plugins:base_plugin",
         "//tensorboard/util:grpc_util",

tensorboard/plugins/core/core_plugin.py

@@ -31,6 +31,7 @@
 from tensorboard.plugins import base_plugin
 from tensorboard.util import grpc_util
 from tensorboard.util import tb_logging
+from tensorboard import version
 
 logger = tb_logging.get_logger()
 
@@ -50,18 +51,24 @@ class CorePlugin(base_plugin.TBPlugin):
 
     plugin_name = "core"
 
-    def __init__(self, context):
+    def __init__(self, context, include_debug_info=None):
         """Instantiates CorePlugin.
 
         Args:
           context: A base_plugin.TBContext instance.
+          include_debug_info: If true, `/data/environment` will include some
+            basic information like the TensorBoard server version. Disabled by
+            default to prevent surprising information leaks in custom builds of
+            TensorBoard.
         """
+        self._flags = context.flags
         logdir_spec = context.flags.logdir_spec if context.flags else ""
         self._logdir = context.logdir or logdir_spec
         self._window_title = context.window_title
         self._path_prefix = context.flags.path_prefix if context.flags else None
         self._assets_zip_provider = context.assets_zip_provider
         self._data_provider = context.data_provider
+        self._include_debug_info = bool(include_debug_info)
 
     def is_active(self):
         return True
@@ -165,13 +172,7 @@ def _serve_index(self, index_asset_bytes, request):
 
     @wrappers.Request.application
     def _serve_environment(self, request):
-        """Serve a JSON object containing some base properties used by the
-        frontend.
-
-        * data_location is either a path to a directory or an address to a
-          database (depending on which mode TensorBoard is running in).
-        * window_title is the title of the TensorBoard web page.
-        """
+        """Serve a JSON object describing the TensorBoard parameters."""
         ctx = plugin_util.context(request.environ)
         experiment = plugin_util.experiment_id(request.environ)
         data_location = self._data_provider.data_location(
@@ -182,6 +183,7 @@ def _serve_environment(self, request):
         )
 
         environment = {
+            "version": version.VERSION,
             "data_location": data_location,
             "window_title": self._window_title,
         }
@@ -193,12 +195,37 @@ def _serve_environment(self, request):
                     "creation_time": experiment_metadata.creation_time,
                 }
             )
+        if self._include_debug_info:
+            environment["debug"] = {
+                "data_provider": str(self._data_provider),
+                "flags": self._render_flags(),
+            }
         return http_util.Respond(
             request,
             environment,
             "application/json",
         )
 
+    def _render_flags(self):
+        """Return a JSON-and-human-friendly version of `self._flags`.
+
+        Like `json.loads(json.dumps(self._flags, default=str))` but
+        without the wasteful serialization overhead.
+        """
+        if self._flags is None:
+            return None
+
+        def go(x):
+            if isinstance(x, (type(None), str, int, float)):
+                return x
+            if isinstance(x, (list, tuple)):
+                return [go(v) for v in x]
+            if isinstance(x, dict):
+                return {str(k): go(v) for (k, v) in x.items()}
+            return str(x)
+
+        return go(vars(self._flags))
+
     @wrappers.Request.application
     def _serve_logdir(self, request):
         """Respond with a JSON object containing this TensorBoard's logdir."""
@@ -270,6 +297,9 @@ def _serve_experiment_runs(self, request):
 class CorePluginLoader(base_plugin.TBLoader):
     """CorePlugin factory."""
 
+    def __init__(self, include_debug_info=None):
+        self._include_debug_info = include_debug_info
+
     def define_flags(self, parser):
         """Adds standard TensorBoard CLI flags to parser."""
         parser.add_argument(
@@ -640,7 +670,7 @@ def fix_flags(self, flags):
 
     def load(self, context):
         """Creates CorePlugin instance."""
-        return CorePlugin(context)
+        return CorePlugin(context, include_debug_info=self._include_debug_info)
 
 
 def _gzip(bytestring):

tensorboard/plugins/core/core_plugin_test.py

@@ -190,6 +190,27 @@ def testEnvironmentForLogdir(self):
         parsed_object = self._get_json(self.server, "/data/environment")
         self.assertEqual(parsed_object["data_location"], self.get_temp_dir())
 
+    def testEnvironmentDebugOffByDefault(self):
+        parsed_object = self._get_json(self.server, "/data/environment")
+        self.assertNotIn("debug", parsed_object)
+
+    def testEnvironmentDebugOnExplicitly(self):
+        multiplexer = event_multiplexer.EventMultiplexer()
+        logdir = self.get_temp_dir()
+        provider = data_provider.MultiplexerDataProvider(multiplexer, logdir)
+        context = base_plugin.TBContext(
+            assets_zip_provider=get_test_assets_zip_provider(),
+            logdir=logdir,
+            data_provider=provider,
+            window_title="title foo",
+        )
+        plugin = core_plugin.CorePlugin(context, include_debug_info=True)
+        app = application.TensorBoardWSGI([plugin])
+        server = werkzeug_test.Client(app, wrappers.BaseResponse)
+
+        parsed_object = self._get_json(server, "/data/environment")
+        self.assertIn("debug", parsed_object)
+
     def testLogdir(self):
         """Test the format of the data/logdir endpoint."""
         parsed_object = self._get_json(self.server, "/data/logdir")