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Docker Intermediate About 30 min +220 XP

Published Frontend Port Refuses Connections

Requests to the frontend on host port 8089 connect and then get an empty reply, although the container is Up and the port is published.

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Briefing

The frontend release container came up ten minutes ago and Docker lists the 8089 to 3000 mapping exactly as the README describes, but the external check has failed ever since.

The Dockerfile was adapted this week from the script developers use to run the site on their laptops, so the container would behave the way everyone is used to.

Nothing in the container's log looks like an error.

Sam thinks docker-proxy on this host is wedged and wants to restart the Docker daemon, which would take every other container on the box down with it.

The fix is yours to find: hints, the recovery checks and the debrief unlock inside the incident.

How it plays

  1. 01

    Get paged

    The alert fires and the clock starts. Read the page and the briefing.

  2. 02

    Investigate

    Work in a simulated shell with realistic output: logs, configs, services.

  3. 03

    Fix it

    Change the system the way you would in production. Hints are there if you get stuck.

  4. 04

    Prove it

    Automated checks verify the recovery, then the debrief explains what happened.

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