Resource Saver enabled by default after upgrade to v4.62.0 silently shuts down Docker engine after 5 min idle

[debugmcpdev]

Description

After upgrading Docker Desktop from v4.58.0 to v4.62.0 on Windows, the Resource Saver feature (useResourceSaver) is enabled by default with a 5-minute idle timeout (autoPauseTimeoutSeconds: 300). This causes the entire Docker engine and backend to shut down silently after 5 minutes of inactivity.

This is a breaking change in behavior for users upgrading from previous versions where this feature did not exist or was not enabled.

Impact

• The Docker engine shuts down completely — not just the UI, but the daemon itself
• docker CLI commands fail with Cannot connect to the Docker daemon
• No user-visible notification or warning is shown before or during shutdown
• Containers stop running, breaking CI/CD pipelines, dev environments, and any tooling that depends on Docker being available
• The Electron UI log shows no error or shutdown message — it simply stops logging, making it very difficult to diagnose
• The only clue is monitor exited: exit status 1 buried in the backend monitor log

Steps to Reproduce

1. Have Docker Desktop v4.58.0 (or earlier) running normally
2. Allow Docker Desktop to auto-update to v4.62.0
3. After the update completes, leave Docker idle for ~5 minutes (no container operations)
4. Observe: Docker engine shuts down, UI disappears, docker ps fails

Expected Behavior

• Upgrading Docker Desktop should not silently change idle behavior that causes the engine to shut down
• If Resource Saver is to be enabled by default on new installs, it should not be force-enabled on upgrades from versions that didn't have it
• At minimum, a notification/toast should be shown explaining that Resource Saver is now active and how to disable it
• The shutdown should be clearly logged in the Electron log (not just a silent stop)

Suggested Fix

One or more of:

1. Do not enable Resource Saver by default on upgrades — only on fresh installs
2. Show a one-time notification after upgrade explaining the new feature and how to configure it
3. Log a clear message in the Electron log when Resource Saver triggers a shutdown (e.g., [ResourceSaver] Shutting down Docker engine after 300s of inactivity)
4. Increase the default timeout — 5 minutes is very aggressive for development workflows where you might pause to write code, review docs, etc.

Workaround

Disable Resource Saver via Docker Desktop UI: Settings > Resources > Resource Saver > OFF

Or via the backend API named pipe:

$pipe = New-Object System.IO.Pipes.NamedPipeClientStream('.', 'dockerBackendApiServer', 'InOut')
$pipe.Connect(5000)
$w = New-Object System.IO.StreamWriter($pipe)
$body = '{"desktop":{"useResourceSaver":false}}'
$req = "POST /app/settings HTTP/1.1`r`nHost: localhost`r`nContent-Type: application/json`r`nContent-Length: $($body.Length)`r`n`r`n$body"
$w.Write($req); $w.Flush(); Start-Sleep 1; $pipe.Close()

Environment

• Docker Desktop: v4.62.0 (upgraded from v4.58.0)
• Docker Engine: v29.2.1
• OS: Windows 11 Pro (Build 26200)
• Previous behavior: Docker engine stayed running indefinitely regardless of idle state