Docker · infra · fg-0265

network_mode: host on Docker Desktop for Mac does not expose the app on the Mac's localhost

curl localhost:3000 on the Mac is refused while the container logs show the server listening

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

On Docker Desktop, host networking means the Linux VM's network unless the opt-in host networking feature is on. That feature needs Desktop 4.34 or later, works only at layer 4 for Linux containers, and is off by default.

Fix

Publish ports with -p or ports instead of host networking, or turn the feature on in settings on 4.34 or later.

Apply

Docker Desktop > Settings > Resources > Network > Enable host networking > Apply and restart

Affects: Docker Desktop for Mac and Windows; unsupported before 4.34, opt-in from 4.34 (2024)

Sources

• https://docs.docker.com/engine/network/drivers/host/
• https://docs.docker.com/desktop/release-notes/

claude mcp add --transport http footgun https://getfootgun.com/api/mcp