[RSDK-11498] Make the client an async context manager (#1009)

As the Jira ticket describes, we used to have code like this:
```python
client = None
try:
    client = await ViamClient.create_from_dial_options(...)
    ...  # use the client
finally:
    if client is not None:
        await client.close()
```
and now we can have code like this:
```python
async with ViamClient.create_from_dial_options(...) as client:
    ...  # use the client
```

Author: penguinland

docs/examples/example.ipynb

@@ -137,9 +137,8 @@
     "        return await RobotClient.with_channel(channel, RobotClient.Options(refresh_interval=10, log_level=logging.FATAL))\n",
     "\n",
     "\n",
-    "robot = await connect_with_channel()\n",
-    "print(robot.resource_names)\n",
-    "await robot.close()"
+    "async with await connect_with_channel() as robot:\n",
+    "    print(robot.resource_names)"
    ]
   },
   {
@@ -163,14 +162,11 @@
     "from viam.media.video import CameraMimeType\n",
     "from viam.media.utils.pil import viam_to_pil_image\n",
     "\n",
-    "robot = await connect_with_channel()\n",
-    "camera = Camera.from_robot(robot, \"camera0\")\n",
-    "image = await camera.get_image(CameraMimeType.JPEG)\n",
-    "pil = viam_to_pil_image(image)\n",
-    "pil.save(\"foo.png\")\n",
-    "\n",
-    "# Don't forget to close the robot when you're done!\n",
-    "await robot.close()"
+    "async with await connect_with_channel() as robot:\n",
+    "    camera = Camera.from_robot(robot, \"camera0\")\n",
+    "    image = await camera.get_image(CameraMimeType.JPEG)\n",
+    "    pil = viam_to_pil_image(image)\n",
+    "    pil.save(\"foo.png\")"
    ]
   },
   {
@@ -215,26 +211,9 @@
     "\n",
     "\n",
     "async def vision():\n",
-    "    robot = await connect_with_channel()\n",
-    "    vision = VisionClient.from_robot(robot)\n",
-    "    detections = await vision.get_detections_from_camera(\"camera_1\", \"detector_1\")"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "At the end, don't forget to close the connection"
-   ]
-  },
-  {
-   "cell_type": "code",
-   "execution_count": 5,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "async def cleanup():\n",
-    "    await robot.close()"
+    "    async with await connect_with_channel() as robot:\n",
+    "        vision = VisionClient.from_robot(robot)\n",
+    "        detections = await vision.get_detections_from_camera(\"camera_1\", \"detector_1\")"
    ]
   },
   {

src/viam/app/app_client.py

@@ -530,11 +530,9 @@ async def connect() -> ViamClient:
         async def main():
 
             # Make a ViamClient
-            viam_client = await connect()
-            # Instantiate an AppClient called "cloud" to run cloud app API methods on
-            cloud = viam_client.app_client
-
-            viam_client.close()
+            async with await connect() as viam_client:
+                # Instantiate an AppClient called "cloud" to run cloud app API methods on
+                cloud = viam_client.app_client
 
         if __name__ == '__main__':
             asyncio.run(main())

src/viam/app/billing_client.py

@@ -42,11 +42,9 @@ async def connect() -> ViamClient:
 
         async def main():
             # Make a ViamClient
-            viam_client = await connect()
-            # Instantiate a BillingClient to run billing client API methods on
-            billing_client = viam_client.billing_client
-
-            viam_client.close()
+            async with await connect() as viam_client:
+                # Instantiate a BillingClient to run billing client API methods on
+                billing_client = viam_client.billing_client
 
         if __name__ == '__main__':
             asyncio.run(main())

src/viam/app/data_client.py

@@ -136,11 +136,9 @@ async def connect() -> ViamClient:
 
         async def main():
             # Make a ViamClient
-            viam_client = await connect()
-            # Instantiate a DataClient to run data client API methods on
-            data_client = viam_client.data_client
-
-            viam_client.close()
+            async with await connect() as viam_client:
+                # Instantiate a DataClient to run data client API methods on
+                data_client = viam_client.data_client
 
         if __name__ == '__main__':
             asyncio.run(main())
@@ -1888,9 +1886,8 @@ async def file_upload_from_path(
         path = Path(filepath)
         file_name = path.stem
         file_extension = path.suffix if path.suffix != "" else None
-        f = open(filepath, "rb")
-        data = f.read()
-        f.close()
+        with open(filepath, "rb") as f:
+            data = f.read()
 
         metadata = UploadMetadata(
             part_id=part_id,

src/viam/app/ml_training_client.py

@@ -46,11 +46,9 @@ async def connect() -> ViamClient:
         async def main():
 
             # Make a ViamClient
-            viam_client = await connect()
-            # Instantiate an MLTrainingClient to run ML training client API methods on
-            ml_training_client = viam_client.ml_training_client
-
-            viam_client.close()
+            async with await connect() as viam_client:
+                # Instantiate an MLTrainingClient to run ML training client API methods on
+                ml_training_client = viam_client.ml_training_client
 
         if __name__ == '__main__':
             asyncio.run(main())

src/viam/app/provisioning_client.py

@@ -41,11 +41,9 @@ async def connect() -> ViamClient:
         async def main():
 
             # Make a ViamClient
-            viam_client = await connect()
-            # Instantiate a ProvisioningClient to run provisioning client API methods on
-            provisioning_client = viam_client.provisioning_client
-
-            viam_client.close()
+            async with await connect() as viam_client:
+                # Instantiate a ProvisioningClient to run provisioning client API methods on
+                provisioning_client = viam_client.provisioning_client
 
         if __name__ == '__main__':
             asyncio.run(main())

src/viam/app/viam_client.py

@@ -1,5 +1,5 @@
 import os
-from typing import Mapping, Optional
+from typing import Any, Mapping, Optional
 
 from grpclib.client import Channel
 from typing_extensions import Self
@@ -206,6 +206,24 @@ async def main():
         """
         return ProvisioningClient(self._channel, self._metadata)
 
+    async def __aenter__(self) -> "ViamClient":
+        """A ViamClient can act as an asynchronous context manager. It will do nothing special when
+        the context is entered.
+        """
+        return self
+
+    async def __aexit__(self, exc_type: Optional[type], exc_value: Optional[BaseException], traceback: Optional[Any]) -> None:
+        """A ViamClient can act as an asynchronous context manager. It will close itself when
+        the context is exited.
+
+        ::
+
+            async with ViamClient.create_from_dial_options(...) as client:
+                await do_something_with(client)
+            # client is closed here
+        """
+        self.close()
+
     def close(self) -> None:
         """Close opened channels used for the various service stubs initialized."""
         if self._closed: