Want to be able to scale you application so it has mutiple instances of the same app? We can do this by running the app on a particular port.

Create 3 Docker containers from our Image

This will assign each instance a random and unused port from Docker named instance1, instance2, instance3

docker run -d -P --name instance1 mattwen/discord-draw:latest
docker run -d -P --name instance2 mattwen/discord-draw:latest
docker run -d -P --name instance3 mattwen/discord-draw:latest

Review the port numbers

docker container list -a

Docker created the app on ports 32768-32770 and directs to internal port 8080 (the port that the app is running on)

Inside Google Cloud Dashboard > Hamburger(Top Left corner) > VPC Network > Firewall Rules Create a Google Cloud VPN Exception for the new ports:

Add a name and the following information:

Visit the public ip address of your Compute Engine VM and verify it’s working!

Each port resolution now has it’s own unique app running inside of it!