Docker-Compose with nginx on different port

[rimelek (Ákos Takács)]

Normally that would be true, but that restriction is disabled for containers.

Non-root user able to bind to port 80; why?

I have learned something new today. A short research shows that kernel 4.11 introduced the sysctl parameter ipv4.ip_unprivileged_port_start, which is responsible for this. By default, it is set to 1024, but Docker will set it to 0 for created containers.

You will still need to et the por tin the url if the port is not the default of the protocol.