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Zakariyau Mukhtar
Zakariyau Mukhtar

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From Vibe-Coding to Engineering: My 48-Hour Battle with Docker & Windows

#programming #cloud #devops

I started this weekend with a simple goal: set up a local development environment. I wanted a vanilla HTML/JS frontend, a Node.js backend, and a MongoDB database running in a Docker container (plus Mongo Express to visualize the data).

Prior to this, I had zero knowledge of JavaScript. I was just following a video tutorial, copying code I didn't fully understand, and hoping for the best.

I thought it would take an hour. Instead, it took a frustrated bike ride home, a Sunday spent journaling, and a deep dive into how Docker actually works to get it running. Here is the full story.

The Setup (Copying blindly)

I started by copying the frontend code. It was a simple User Profile page where you could toggle between "View" and "Edit" modes.

My index.html:

<script>
    function saveProfile() {
        document.querySelector('#name').textContent = document.querySelector('#input-name').value
        // ... more DOM manipulation
    }
</script>
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My server.js:

var express = require('express');
var app = express();
app.use(express.static(__dirname)); 
app.listen(3000, function () {
    console.log("app listening on port 3000!");
});
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So far, so good. The frontend worked. Then came Docker.

Phase 1 The "Name Does Not Resolve" Loop:

I pulled the mongo and mongo-express images and tried to run them using long CLI commands I found online. I checked docker ps, and everything looked fine.

But when I checked the logs for Mongo Express, I saw this error over and over:

/docker-entrypoint.sh: line 15: mongo: Name does not resolve

I spent 30 minutes spinning up containers, deleting them, and spinning them up again. I eventually turned to AI for help. It suggested I stop everything, wipe the containers, and create a dedicated network.

I ran:

docker network create mongo-network
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Then I restarted the containers attached to that network. The error persisted. I was stuck in a loop of trying random commands without understanding why they failed.

Phase 2: The Mystery of "Pass" vs "Password"-

Once I finally got the containers talking, I couldn't log in to Mongo Express.

I had explicitly set my environment variables to:

  • ME_CONFIG_BASICAUTH_USERNAME=admin
  • ME_CONFIG_BASICAUTH_PASSWORD=password

But every time I tried to log in with admin / password, it failed.

After a lot of trial and error, I tried logging in with pass. It worked.

I realized that because of how I was passing arguments in PowerShell, Docker wasn't picking up my password variable. It was defaulting to the container's built-in security settings (admin:pass). I had to completely restructure my docker run command to ensure the variables were actually being read.

Phase 3: The Saturday Night "Vibecoding" Crash-

By 9 PM on Saturday, I hit a wall.

I ran my Node.js server and tried to edit a profile. The terminal said:

Connecting to the db....

And then... silence. It just froze.

I tried everything the AI suggested, but nothing worked. I didn't even understand half the commands I was typing. I realized I was just "vibecoding" typing random things hoping for a miracle. I was frustrated. I packed up, left the office, and took a bike ride home to clear my head.

Phase 4: The Monday Morning Fix

On Sunday, I didn't touch the code. I just journaled. I wrote down a plan: Understand the problem, then fix it.

On Monday, I came back fresh. I wiped every container and image (docker system prune) and started from scratch.

The "Windows Hang" (IPv4 vs IPv6)

I realized why the app was freezing. On Windows, localhost often resolves to the IPv6 address ::1. However, Docker Desktop for Windows listens on the IPv4 address 127.0.0.1.

My Node app was knocking on the IPv6 door, but Docker was at the IPv4 house.

I changed my connection string in server.js:

  • Bad: mongodb://admin:password@localhost:27017
  • Good: mongodb://admin:password@127.0.0.1:27017

The Version Mismatch

Even with the connection fixed, I got errors. I looked at my package.json.
I had installed the latest mongodb version (v6.0+), which uses Promises. But the tutorial code I copied was written for version 3.8, which used Callbacks.

I uninstalled the new version and forced a downgrade:

npm install mongodb@3.7.3
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I restarted the server. I clicked "Save Profile." It worked.

Conclusion

This project was supposed to be a quick setup, but it turned into a crash course in DevOps. I learned:

  1. Don't trust localhost on Windows. Always use 127.0.0.1.
  2. Check your dependencies. Copy-pasting old code requires old packages.
  3. Stop "Vibecoding." If you don't understand the command, don't run it. Step back, journal, and come back fresh.

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