How to Port Forward Docker-Machine to Localhost

Dimas Maulana Development

08-03-2016

Contents

Port forwarding allows you to expose services running inside a virtual machine, such as Docker-Machine, to your local machine. In this example, we’ll use VirtualBox and Docker-Machine to forward port 8080 from the virtual machine to localhost.

Prerequisites

Before you begin, make sure you have the following:

Docker-Machine installed.
VirtualBox installed.
The virtual machine you want to configure, e.g., boot2docker-vm.

Step 1: Open a Terminal

Open a terminal on your local machine. You’ll use this terminal to run commands to configure port forwarding.

Step 2: List Virtual Machines

Run the following command to list the virtual machines managed by Docker-Machine:

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docker-machine ls

This command will display a list of virtual machines, including their names and status. Make a note of the name of the virtual machine you want to configure for port forwarding.

Step 3: Configure Port Forwarding

Use the VBoxManage command to configure port forwarding for your virtual machine. There are two variations of the command you provided in your question:

To forward port 8080 from the virtual machine to port 8080 on your local machine:
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VBoxManage controlvm <your-vm-name> natpf1 "nginx,tcp,,8080,,8080"
To forward port 8080 from the virtual machine to port 8080 on 127.0.0.1 (localhost) on your local machine:
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VBoxManage controlvm <your-vm-name> natpf1 "nginx,tcp,127.0.0.1,8080,,8080"

Replace <your-vm-name> with the actual name of your virtual machine obtained from the docker-machine ls command.

Step 4: Verify Port Forwarding

To ensure that the port forwarding is configured correctly, you can run the following command to check the port forwarding rules for your virtual machine:

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VBoxManage showvminfo <your-vm-name> --machinereadable

Look for the section that begins with "Forwarding(0)". It should display the port forwarding rule you’ve just added.

Step 5: Access the Service

Now that you’ve configured port forwarding, you can access the service running inside your Docker-Machine virtual machine by accessing http://localhost:8080 in your web browser.

That’s it! You’ve successfully set up port forwarding from your Docker-Machine virtual machine to your local machine, allowing you to access services running in the virtual machine as if they were running locally.