Emit events from the kernels service and gateway client (jupyter-serv…

…er#1252)

* Emit events from the kernels service and gateway client

* clean-up after code review

* Make GatewayKernelManager a compatible subclass to ServerKernelManager

* Add events to gateway lifecycle test

* Access event_logger trait from ServerApp

---------

Co-authored-by: Raj Musuku <r_musuku@apple.com>
Co-authored-by: Zach Sailer <zsailer@apple.com>
Co-authored-by: Kevin Bates <kbates4@gmail.com>

jupyter_server/event_schemas/gateway_client/v1.yaml

@@ -0,0 +1,40 @@
+"$id": https://events.jupyter.org/jupyter_server/gateway_client/v1
+version: 1
+title: Gateway Client activities.
+personal-data: true
+description: |
+  Record events of a gateway client.
+type: object
+required:
+ - status
+ - msg
+properties:
+  status:
+    enum:
+      - error
+      - success
+    description: |
+      Status received by Gateway client based on the rest api operation to gateway kernel.
+
+      This is a required field.
+
+      Possible values:
+
+      1. error
+         Error response from a rest api operation to gateway kernel.
+
+      2. success
+         Success response from a rest api operation to gateway kernel.
+  status_code:
+    type: number
+    description: |
+      Http response codes from a rest api operation to gateway kernel.
+      Examples: 200, 400, 502, 503, 599 etc.
+  msg:
+    type: string
+    description: |
+      Description of the event being emitted.
+  gateway_url:
+    type: string
+    description: |
+      Gateway url where the remote server exist.

jupyter_server/event_schemas/kernel_actions/v1.yaml

@@ -0,0 +1,71 @@
+"$id": https://events.jupyter.org/jupyter_server/kernel_actions/v1
+version: 1
+title: Kernel Manager activities
+personal-data: true
+description: |
+  Record events of a kernel manager.
+type: object
+required:
+  - action
+  - kernel_id
+  - msg
+properties:
+  action:
+    enum:
+      - start
+      - interrupt
+      - shutdown
+      - restart
+    description: |
+      Action performed by the Kernel Manager.
+
+      This is a required field.
+
+      Possible values:
+
+      1. start
+         A kernel has been started with the given kernel id.
+
+      2. interrupt
+         A kernel has been interrupted for the given kernel id.
+
+      3. shutdown
+         A kernel has been shut down for the given kernel id.
+
+      4. restart
+         A kernel has been restarted for the given kernel id.
+  kernel_id:
+    type: string
+    description: |
+      Kernel id.
+
+      This is a required field.
+  kernel_name:
+    type: string
+    description: |
+      Name of the kernel.
+  status:
+    enum:
+      - error
+      - success
+    description: |
+      Status received from a rest api operation to kernel server.
+
+      This is a required field.
+
+      Possible values:
+
+      1. error
+         Error response from a rest api operation to kernel server.
+
+      2. success
+         Success response from a rest api operation to kernel server.
+  status_code:
+    type: number
+    description: |
+      Http response codes from a rest api operation to kernel server.
+      Examples: 200, 400, 502, 503, 599 etc
+  msg:
+    type: string
+    description: |
+      Description of the event specified in action.

jupyter_server/gateway/gateway_client.py

@@ -12,11 +12,31 @@
 from http.cookies import SimpleCookie
 from socket import gaierror
 
+from jupyter_events import EventLogger
 from tornado import web
 from tornado.httpclient import AsyncHTTPClient, HTTPClientError, HTTPResponse
-from traitlets import Bool, Float, Int, TraitError, Type, Unicode, default, observe, validate
+from traitlets import (
+    Bool,
+    Float,
+    Instance,
+    Int,
+    TraitError,
+    Type,
+    Unicode,
+    default,
+    observe,
+    validate,
+)
 from traitlets.config import LoggingConfigurable, SingletonConfigurable
 
+from jupyter_server import DEFAULT_EVENTS_SCHEMA_PATH, JUPYTER_SERVER_EVENTS_URI
+
+ERROR_STATUS = "error"
+SUCCESS_STATUS = "success"
+STATUS_KEY = "status"
+STATUS_CODE_KEY = "status_code"
+MESSAGE_KEY = "msg"
+
 if ty.TYPE_CHECKING:
     from http.cookies import Morsel
 
@@ -71,10 +91,30 @@ def get_token(
 class GatewayClient(SingletonConfigurable):
     """This class manages the configuration.  It's its own singleton class so
     that we can share these values across all objects.  It also contains some
-    helper methods to build request arguments out of the various config
     options.
+    helper methods to build request arguments out of the various config
     """
 
+    event_schema_id = JUPYTER_SERVER_EVENTS_URI + "/gateway_client/v1"
+    event_logger = Instance(EventLogger).tag(config=True)
+
+    @default("event_logger")
+    def _default_event_logger(self):
+        if self.parent and hasattr(self.parent, "event_logger"):
+            # Event logger is attached from serverapp.
+            return self.parent.event_logger
+        else:
+            # If parent does not have an event logger, create one.
+            logger = EventLogger()
+            schema_path = DEFAULT_EVENTS_SCHEMA_PATH / "gateway_client" / "v1.yaml"
+            logger.register_event_schema(schema_path)
+            self.log.info("Event is registered in GatewayClient.")
+            return logger
+
+    def emit(self, data):
+        """Emit event using the core event schema from Jupyter Server's Gateway Client."""
+        self.event_logger.emit(schema_id=self.event_schema_id, data=data)
+
     url = Unicode(
         default_value=None,
         allow_none=True,
@@ -97,7 +137,9 @@ def _url_validate(self, proposal):
         value = proposal["value"]
         # Ensure value, if present, starts with 'http'
         if value is not None and len(value) > 0 and not str(value).lower().startswith("http"):
-            raise TraitError("GatewayClient url must start with 'http': '%r'" % value)
+            message = "GatewayClient url must start with 'http': '%r'" % value
+            self.emit(data={STATUS_KEY: ERROR_STATUS, STATUS_CODE_KEY: 400, MESSAGE_KEY: message})
+            raise TraitError(message)
         return value
 
     ws_url = Unicode(
@@ -123,7 +165,9 @@ def _ws_url_validate(self, proposal):
         value = proposal["value"]
         # Ensure value, if present, starts with 'ws'
         if value is not None and len(value) > 0 and not str(value).lower().startswith("ws"):
-            raise TraitError("GatewayClient ws_url must start with 'ws': '%r'" % value)
+            message = "GatewayClient ws_url must start with 'ws': '%r'" % value
+            self.emit(data={STATUS_KEY: ERROR_STATUS, STATUS_CODE_KEY: 400, MESSAGE_KEY: message})
+            raise TraitError(message)
         return value
 
     kernels_endpoint_default_value = "/api/kernels"
@@ -728,6 +772,9 @@ async def gateway_request(endpoint: str, **kwargs: ty.Any) -> HTTPResponse:
     # NOTE: We do this here since this handler is called during the server's startup and subsequent refreshes
     # of the tree view.
     except HTTPClientError as e:
+        GatewayClient.instance().emit(
+            data={STATUS_KEY: ERROR_STATUS, STATUS_CODE_KEY: e.code, MESSAGE_KEY: str(e.message)}
+        )
         error_reason = f"Exception while attempting to connect to Gateway server url '{GatewayClient.instance().url}'"
         error_message = e.message
         if e.response:
@@ -744,12 +791,18 @@ async def gateway_request(endpoint: str, **kwargs: ty.Any) -> HTTPResponse:
             "Ensure gateway url is valid and the Gateway instance is running.",
         ) from e
     except ConnectionError as e:
+        GatewayClient.instance().emit(
+            data={STATUS_KEY: ERROR_STATUS, STATUS_CODE_KEY: 503, MESSAGE_KEY: str(e)}
+        )
         raise web.HTTPError(
             503,
             f"ConnectionError was received from Gateway server url '{GatewayClient.instance().url}'.  "
             "Check to be sure the Gateway instance is running.",
         ) from e
     except gaierror as e:
+        GatewayClient.instance().emit(
+            data={STATUS_KEY: ERROR_STATUS, STATUS_CODE_KEY: 404, MESSAGE_KEY: str(e)}
+        )
         raise web.HTTPError(
             404,
             f"The Gateway server specified in the gateway_url '{GatewayClient.instance().url}' doesn't "

jupyter_server/gateway/managers.py

@@ -15,15 +15,18 @@
 from jupyter_client.asynchronous.client import AsyncKernelClient
 from jupyter_client.clientabc import KernelClientABC
 from jupyter_client.kernelspec import KernelSpecManager
-from jupyter_client.manager import AsyncKernelManager
 from jupyter_client.managerabc import KernelManagerABC
 from jupyter_core.utils import ensure_async
 from tornado import web
 from tornado.escape import json_decode, json_encode, url_escape, utf8
 from traitlets import DottedObjectName, Instance, Type, default
 
-from .._tz import UTC
-from ..services.kernels.kernelmanager import AsyncMappingKernelManager
+from .._tz import UTC, utcnow
+from ..services.kernels.kernelmanager import (
+    AsyncMappingKernelManager,
+    ServerKernelManager,
+    emit_kernel_action_event,
+)
 from ..services.sessions.sessionmanager import SessionManager
 from ..utils import url_path_join
 from .gateway_client import GatewayClient, gateway_request
@@ -79,7 +82,6 @@ async def start_kernel(self, *, kernel_id=None, path=None, **kwargs):
         await km.start_kernel(kernel_id=kernel_id, **kwargs)
         kernel_id = km.kernel_id
         self._kernels[kernel_id] = km
-
         # Initialize culling if not already
         if not self._initialized_culler:
             self.initialize_culler()
@@ -366,7 +368,7 @@ async def kernel_culled(self, kernel_id: str) -> bool:  # typing: ignore
         return km is None
 
 
-class GatewayKernelManager(AsyncKernelManager):
+class GatewayKernelManager(ServerKernelManager):
     """Manages a single kernel remotely via a Gateway Server."""
 
     kernel_id: Optional[str] = None  # type:ignore[assignment]
@@ -385,7 +387,8 @@ def __init__(self, **kwargs):
         self.kernel_url: str
         self.kernel = self.kernel_id = None
         # simulate busy/activity markers:
-        self.execution_state = self.last_activity = None
+        self.execution_state = "starting"
+        self.last_activity = utcnow()
 
     @property
     def has_kernel(self):
@@ -458,6 +461,9 @@ async def refresh_model(self, model=None):
     # Kernel management
     # --------------------------------------------------------------------------
 
+    @emit_kernel_action_event(
+        success_msg="Kernel {kernel_id} was started.",
+    )
     async def start_kernel(self, **kwargs):
         """Starts a kernel via HTTP in an asynchronous manner.
 
@@ -509,6 +515,9 @@ async def start_kernel(self, **kwargs):
             self.kernel = await self.refresh_model()
             self.log.info(f"GatewayKernelManager using existing kernel: {self.kernel_id}")
 
+    @emit_kernel_action_event(
+        success_msg="Kernel {kernel_id} was shutdown.",
+    )
     async def shutdown_kernel(self, now=False, restart=False):
         """Attempts to stop the kernel process cleanly via HTTP."""
 
@@ -523,6 +532,9 @@ async def shutdown_kernel(self, now=False, restart=False):
                 else:
                     raise
 
+    @emit_kernel_action_event(
+        success_msg="Kernel {kernel_id} was restarted.",
+    )
     async def restart_kernel(self, **kw):
         """Restarts a kernel via HTTP."""
         if self.has_kernel:
@@ -537,6 +549,9 @@ async def restart_kernel(self, **kw):
             )
             self.log.debug("Restart kernel response: %d %s", response.code, response.reason)
 
+    @emit_kernel_action_event(
+        success_msg="Kernel {kernel_id} was interrupted.",
+    )
     async def interrupt_kernel(self):
         """Interrupts the kernel via an HTTP request."""
         if self.has_kernel:
@@ -556,8 +571,10 @@ async def is_alive(self):
         if self.has_kernel:
             # Go ahead and issue a request to get the kernel
             self.kernel = await self.refresh_model()
+            self.log.debug(f"The kernel: {self.kernel} is alive.")
             return True
         else:  # we don't have a kernel
+            self.log.debug(f"The kernel: {self.kernel} no longer exists.")
             return False
 
     def cleanup_resources(self, restart=False):

jupyter_server/serverapp.py

@@ -1964,6 +1964,8 @@ def init_event_logger(self):
         # events URI, `JUPYTER_SERVER_EVENTS_URI`.
         schema_ids = [
             "https://events.jupyter.org/jupyter_server/contents_service/v1",
+            "https://events.jupyter.org/jupyter_server/gateway_client/v1",
+            "https://events.jupyter.org/jupyter_server/kernel_actions/v1",
         ]
         for schema_id in schema_ids:
             # Get the schema path from the schema ID.