Remove outdated guides on connecting Excel to a local LakeFS server and replace with a comprehensive solution using NGINX reverse proxy to address CORS and Private Network Access issues.

Author: ivan m.

_posts/2025-06-23-a-complete-guide-connecting-excel-to-a-local-lakefs-server.md

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+---
+
+title: "Connecting Excel to a Local lakeFS Server"
+date: 2025-06-23 21:29:00 +0400
+categories: [Tech Stack, Troubleshooting]
+tags: [cors, docker, excel, lakefs, nginx, xlwings]
+render_with_liquid: false
+
+---
+
+This guide provides a definitive solution to a common but complex problem: connecting a modern Excel add-in (specifically, xlwings Lite) to a lakeFS server running on your local machine (`localhost`).
+
+When you attempt this, you are likely to be blocked by browser security errors that can be difficult to diagnose. In your browser's developer console, you will typically see a failed `OPTIONS` preflight request in the network tab, followed by a CORS error message similar to this:
+
+> Access to XMLHttpRequest at 'http://localhost:8000/api/v1/repositories' from origin 'https://addin.xlwings.org' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
+
+Before we dive into the technical reasons, let's confirm you're facing this exact issue.
+