Databricks Quest 4-(Deploy Your First Databricks App) success story

[User_sky]

🚀 Deployed Databricks AppKit + Lakebase: 2 Tricky Bugs & How I Solved Them!

Just deployed my first full-stack Databricks App using the AppKit Lakebase (PostgreSQL) template on serverless compute!

Using Gemini as an AI debugging agent via raw CLI logs in WSL, I diagnosed and resolved two critical roadblocks:

• Bug 1: Missing DABs Variables (postgres_project)

  • Fix: Added postgres_project, postgres_branch, and postgres_database directly under the variables: block in databricks.yml to unblock databricks apps deploy.

• Bug 2: "Failed to Fetch Todos" (Silent Permission Denied 42501)

  • Root Cause: Testing locally (npm run dev) first meant my personal user owned the app schema. The deployed app runs under a Service Principal, which was denied write access.

  • Fix: Dropped the schema via DROP SCHEMA IF EXISTS app CASCADE; in the SQL Editor and redeployed. The Service Principal recreated the schema and took proper ownership!

💡 Pro-tip: When building with Lakebase, deploy first, test locally second so your App's Service Principal owns the schema from day one!