apps/orchestrator/src/spawner/docker-sandbox.service.spec.ts

@@ -162,6 +162,42 @@ describe("DockerSandboxService", () => {
       );
     });
 
+    it("should include a random suffix in container name for uniqueness", async () => {
+      const agentId = "agent-123";
+      const taskId = "task-456";
+      const workspacePath = "/workspace/agent-123";
+
+      await service.createContainer(agentId, taskId, workspacePath);
+
+      const callArgs = (mockDocker.createContainer as ReturnType<typeof vi.fn>).mock
+        .calls[0][0] as Docker.ContainerCreateOptions;
+      const containerName = callArgs.name as string;
+
+      // Name format: mosaic-agent-{agentId}-{timestamp}-{8 hex chars}
+      expect(containerName).toMatch(/^mosaic-agent-agent-123-\d+-[0-9a-f]{8}$/);
+    });
+
+    it("should generate unique container names across rapid successive calls", async () => {
+      const agentId = "agent-123";
+      const taskId = "task-456";
+      const workspacePath = "/workspace/agent-123";
+      const containerNames = new Set<string>();
+
+      // Spawn multiple containers rapidly to test for collisions
+      for (let i = 0; i < 20; i++) {
+        await service.createContainer(agentId, taskId, workspacePath);
+      }
+
+      const calls = (mockDocker.createContainer as ReturnType<typeof vi.fn>).mock.calls;
+      for (const call of calls) {
+        const args = call[0] as Docker.ContainerCreateOptions;
+        containerNames.add(args.name as string);
+      }
+
+      // All 20 names must be unique (no collisions)
+      expect(containerNames.size).toBe(20);
+    });
+
     it("should throw error if container creation fails", async () => {
       const agentId = "agent-123";
       const taskId = "task-456";

apps/orchestrator/src/spawner/docker-sandbox.service.ts

@@ -1,5 +1,6 @@
 import { Injectable, Logger } from "@nestjs/common";
 import { ConfigService } from "@nestjs/config";
+import { randomBytes } from "crypto";
 import Docker from "dockerode";
 import {
   DockerSandboxOptions,
@@ -248,8 +249,10 @@ export class DockerSandboxService {
         }
       }
 
-      // Container name with timestamp to ensure uniqueness
-      const containerName = `mosaic-agent-${agentId}-${Date.now().toString()}`;
+      // Container name with timestamp and random suffix to guarantee uniqueness
+      // even when multiple agents are spawned simultaneously within the same millisecond
+      const uniqueSuffix = randomBytes(4).toString("hex");
+      const containerName = `mosaic-agent-${agentId}-${Date.now().toString()}-${uniqueSuffix}`;
 
       this.logger.log(
         `Creating container for agent ${agentId} (image: ${image}, memory: ${memoryMB.toString()}MB, cpu: ${cpuLimit.toString()})`