Showcase: DRA GPU status controller across languages

demo/Dockerfile

@@ -0,0 +1,8 @@
+FROM golang:1.24 AS build
+WORKDIR /src
+COPY . .
+RUN go build -o /out/inventory ./...
+
+FROM gcr.io/distroless/static
+COPY --from=build /out/inventory /inventory
+ENTRYPOINT ["/inventory"]

demo/config.yaml

@@ -5,7 +5,8 @@ metadata:
 spec:
   driver: gpu.example.com
   parameters:
-    sharing: none
-    memory: 16Gi
+    sharing: time-sliced
+    memory: 24Gi
+    replicas: 4
   nodeSelector:
     accelerator: nvidia

demo/go.sum

@@ -1,4 +1,5 @@
-example.com/dra v1.3.0 h1:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa=
-example.com/dra v1.3.0/go.mod h1:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb=
+example.com/dra v1.4.0 h1:eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee=
+example.com/dra v1.4.0/go.mod h1:fffffffffffffffffffffffffffffffffffffffffff=
 k8s.io/api v0.30.0 h1:ccccccccccccccccccccccccccccccccccccccccccc=
 k8s.io/api v0.30.0/go.mod h1:ddddddddddddddddddddddddddddddddddddddddddd=
+k8s.io/klog/v2 v2.120.1 h1:ggggggggggggggggggggggggggggggggggggggggggg=

demo/gpu.go

@@ -3,14 +3,19 @@ package gpu
 
 import (
 	"context"
+	"errors"
 	"fmt"
 )
 
+// ErrNodeNotFound is returned when a node has no inventory yet.
+var ErrNodeNotFound = errors.New("node not found")
+
 // DeviceInfo describes a single GPU exposed to a pod.
 type DeviceInfo struct {
 	Name   string
 	Driver string
 	UUID   string
+	Shared bool
 }
 
 // StatusController reconciles GPU claims against node inventory.
@@ -21,16 +26,24 @@ type StatusController struct {
 func (c *StatusController) getGPUStatus(info DeviceInfo, node string) (string, error) {
 	devices, ok := c.nodes[node]
 	if !ok {
-		return "", fmt.Errorf("node %q not found", node)
+		return "", fmt.Errorf("%w: %q", ErrNodeNotFound, node)
 	}
 	for _, d := range devices {
 		if d.UUID == info.UUID {
+			if d.Shared {
+				return "shared", nil
+			}
 			return "allocated", nil
 		}
 	}
 	return "pending", nil
 }
 
+// Count returns how many devices a node exposes.
+func (c *StatusController) Count(node string) int {
+	return len(c.nodes[node])
+}
+
 func (c *StatusController) Reconcile(ctx context.Context, node string) error {
 	_, err := c.getGPUStatus(DeviceInfo{}, node)
 	return err

demo/old_helper.rs → demo/helper.rs

@@ -6,3 +6,7 @@ pub fn format_uuid(raw: &str) -> String {
 pub fn is_valid(uuid: &str) -> bool {
     uuid.len() == 36 && uuid.chars().filter(|c| *c == '-').count() == 4
 }
+
+pub fn short(uuid: &str) -> &str {
+    uuid.split('-').next().unwrap_or(uuid)
+}

demo/metrics.swift

@@ -0,0 +1,16 @@
+import Foundation
+
+struct GPUMetrics {
+    let uuid: String
+    let utilization: Double
+    let memoryUsed: UInt64
+
+    var isSaturated: Bool {
+        utilization > 0.9
+    }
+}
+
+func summarize(_ samples: [GPUMetrics]) -> String {
+    let busy = samples.filter { $0.isSaturated }.count
+    return "\(busy)/\(samples.count) GPUs saturated"
+}

demo/queries

@@ -0,0 +1,5 @@
+SELECT node, COUNT(*) AS gpus, SUM(memory_gb) AS total_memory
+FROM inventory
+WHERE status = 'ready'
+GROUP BY node
+ORDER BY total_memory DESC;

demo/server.py

@@ -1,13 +1,14 @@
 """A tiny async status server for the DRA controller."""
 import asyncio
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 
 
 @dataclass
 class Claim:
     name: str
     driver: str
     ready: bool = False
+    devices: list[str] = field(default_factory=list)
 
 
 class Server:
@@ -18,5 +19,10 @@ async def add(self, claim: Claim) -> None:
         await asyncio.sleep(0)
         self.claims.append(claim)
 
+    async def ready(self, name: str) -> None:
+        for c in self.claims:
+            if c.name == name:
+                c.ready = True
+
     def pending(self) -> list[Claim]:
         return [c for c in self.claims if not c.ready]

demo/ui.tsx

@@ -0,0 +1,34 @@
+// Copyright 2026 Daniil Antoshin
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { createSignal, For } from "solid-js";
+
+interface Device {
+  uuid: string;
+  status: "allocated" | "pending" | "shared";
+}
+
+export function DeviceList(props: { devices: Device[] }) {
+  const [filter, setFilter] = createSignal("");
+  const shown = () =>
+    props.devices.filter((d) => d.uuid.includes(filter()));
+  return (
+    <section class="devices">
+      <input placeholder="filter…" onInput={(e) => setFilter(e.currentTarget.value)} />
+      <ul>
+        <For each={shown()}>{(d) => <li data-status={d.status}>{d.uuid}</li>}</For>
+      </ul>
+    </section>
+  );
+}