Fix: Docker Connection Refused to ASP.NET Core App

The Error

curl inside container:

curl: (7) Failed to connect to localhost port 5000: Connection refused

Quick Fix - 1 Min

1. Use http://0.0.0.0:5000 not localhost in Dockerfile. 2. ASPNETCORE_URLS=http://+:80 env var. 3. Expose port in docker run: -p 8080:80

Root Cause

Kestrel binds to localhost by default. Docker container localhost!= host localhost.