From b2404836ba57772f4bcc10440b2aed2565007cd1 Mon Sep 17 00:00:00 2001
From: Shaojin Wen <shaojin.wensj@alibaba-inc.com>
Date: Mon, 10 Aug 2026 22:07:54 +0800
Subject: [PATCH] fix(cli): give sandbox containers collision-proof names
 (#8880)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The regular-run container name was allocated by counting docker ps -a
and taking the first free index — a check-then-run window with nothing
holding the name between the count and `docker run --name`. That was
survivable while launches on a shared docker daemon were rare, but the
CI pool packs several runner registrations per host, and a dense
autofix scan launches sandboxes on sibling registrations within the
same second: in run 31389561905, SEVEN of fourteen legs lost the race —
each got `docker: Conflict. The container name "/qwen-code-0.21.8-0" is
already in use` (exit 125) one second into its agent step, burned a
round, and pushed items toward their round caps.

A random 8-hex suffix replaces the counter, the same scheme the
integration-test branch has always used. Nothing predicts the name:
run-agent.mjs parses it from the `ContainerName (regular):` line, and
the stale-container reaper matches on the image-name prefix, which the
suffix preserves. The docker ps call goes with the counter — one less
execSync on the launch path.

Co-authored-by: verify <verify@local>
---
 packages/cli/src/utils/sandbox.ts | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/packages/cli/src/utils/sandbox.ts b/packages/cli/src/utils/sandbox.ts
index 86b76119f6..706ef1dec4 100644
--- a/packages/cli/src/utils/sandbox.ts
+++ b/packages/cli/src/utils/sandbox.ts
@@ -637,16 +637,16 @@ export async function start_sandbox(
     )}`;
     writeStderrLine(`ContainerName: ${containerName}`);
   } else {
-    let index = 0;
-    const containerNameCheck = execSync(
-      `${config.command} ps -a --format "{{.Names}}"`,
-    )
-      .toString()
-      .trim();
-    while (containerNameCheck.includes(`${imageName}-${index}`)) {
-      index++;
-    }
-    containerName = `${imageName}-${index}`;
+    // Random suffix, NOT a counted index: several runner registrations can
+    // share one docker daemon (the CI pool packs multiple runners per
+    // host), and the old count-then-run window let concurrent launches
+    // pick the same index — docker then rejects the loser's `docker run`
+    // with a name Conflict (exit 125). Observed at scale: 7 of 14 legs of
+    // one autofix scan lost that race in a single tick. Consumers that
+    // need the name parse it from the line below rather than predicting
+    // it, and cleanup tooling matches on the image-name prefix, so the
+    // suffix shape is free to be collision-proof.
+    containerName = `${imageName}-${randomBytes(4).toString('hex')}`;
     writeStderrLine(`ContainerName (regular): ${containerName}`);
   }
   args.push('--name', containerName, '--hostname', containerName);