From cf2d2d31b7633f88b4d21c6ea5fa844a2c476a95 Mon Sep 17 00:00:00 2001
From: ansible <ansible@mymx.me>
Date: Tue, 7 Apr 2026 16:07:24 +0000
Subject: [PATCH] Always clean stale taps before creating new ones

deleteTap before createTap in all four call sites:
snapshot restore, cold boot, agent start, snapshot create.
Prevents "Device or resource busy" from leftover taps.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
---
 src/agent-manager.ts | 1 +
 src/snapshot.ts      | 1 +
 src/vm.ts            | 2 ++
 3 files changed, 4 insertions(+)

diff --git a/src/agent-manager.ts b/src/agent-manager.ts
index c938890..0593d44 100644
--- a/src/agent-manager.ts
+++ b/src/agent-manager.ts
@@ -268,6 +268,7 @@ export async function startAgent(
   // Setup network
   ensureBridge();
   ensureNat();
+  deleteTap(tapDevice); // clean stale tap from previous run
   createTap(tapDevice);
 
   // Boot VM
diff --git a/src/snapshot.ts b/src/snapshot.ts
index 2069a2d..b1d751b 100644
--- a/src/snapshot.ts
+++ b/src/snapshot.ts
@@ -63,6 +63,7 @@ export async function createSnapshot() {
   log("Setting up network...");
   ensureBridge();
   ensureNat();
+  deleteTap(snap.tapDevice); // clean stale tap from previous run
   createTap(snap.tapDevice);
 
   let proc: ChildProcess | null = null;
diff --git a/src/vm.ts b/src/vm.ts
index b917197..1946a22 100644
--- a/src/vm.ts
+++ b/src/vm.ts
@@ -78,6 +78,7 @@ export class VMInstance {
       log(verbose, `VM ${id}: restoring from snapshot...`);
       ensureBridge();
       ensureNat();
+      deleteTap(snap.tapDevice); // clean stale tap from previous run
       createTap(snap.tapDevice);
 
       // Spawn firecracker and load snapshot
@@ -155,6 +156,7 @@ export class VMInstance {
       log(verbose, `VM ${id}: creating tap ${tapDevice}...`);
       ensureBridge();
       ensureNat();
+      deleteTap(tapDevice); // clean stale tap from previous run
       createTap(tapDevice);
 
       log(verbose, `VM ${id}: booting...`);