I'm new to Docker and working on setting up my first containers as part of a homelabbing project. Currently, I'm running an Ubuntu VM through Proxmox and have Docker installed. I want to get Nginx Proxy Manager up and running along with other services like Portainer and Pi-hole.
I've created a Docker Compose file for Nginx Proxy Manager, but when I try to run it, I get an error saying there's a port conflict on TCP 443. It seems like there's something already using this port on my Ubuntu VM. I'm not sure how to troubleshoot this or what steps to take next to resolve the issue. Can anyone help me figure out what might be causing this port conflict and how I can fix it?
3 Answers
That's definitely a common issue. Your Docker container can't bind to port 443 because something else is already using it. You could access your VM and see which services are using the ports. Disabling or moving the host web server from port 443 could solve your issue!
It sounds like your Ubuntu VM might already have a web server running that's taking over port 443, which is causing the conflict when Docker tries to expose that port. You might want to check what services are actively running on your VM. If you find something using port 443, you can either stop that service or change your Docker setup to use a different port. Just make sure that you don't have two services trying to use the same port at the same time.
Also, run your Docker commands with root privileges to ensure you have permission to bind to those ports. Sometimes that's necessary for Docker to access certain network resources.
You likely need to adjust the current web server that's using port 443 on your VM. Only one service can bind to the port at a time. You can either change the port for your host web server or disable it altogether. This way, Docker can work without running into conflicts.
Make sure to check all running services; sometimes a previous Docker container or other application may be holding onto the port as well. Identifying those can help.
If that's the case, what you can do is change the port mapping in your Docker Compose file. Instead of forwarding the ports to 443, try using a different port for the container and access it through that. You can then set up Nginx to forward traffic to that port.