I created this guide because I wanted to have a docker container on Ubuntu that ran a Node.js server.

Initial problems I ran into before creating this guide:

• The Docker documentation for this doesn't make much sense, is for a very old version of Docker, and uses CentOS.
• The Docker daemon only works on linux and not OS X - I setup Vagrant for this

Getting Started

You will need VirtualBox and Vagrant installed. This guide will show you how to setup a Vagrant instance that uses VirtualBox and then loads Docker inside the Vagrant VM.

Initialize Vagrant

Run this command from the project's root:

vagrant up

It will begin loading up the VM; during the initialization, it will ask you which network interface you wish to connect to; make sure to choose one that is exposed to the internet. For me this is typically the Wi-Fi (AirPort).

Once it is done, load the vagrant instance:

vagrant ssh

If you get an error about Guest Addition versions not matching, first try:

ls /vagrant

and if you see the contents of this project there, then you're good to go. Vagrant will share the host directory contents that has Vagrantfile as /vagrant in the VM.

Modify UFW

Ubuntu's default UFW will drop incoming connections - to fix this

sudo nano /etc/default/ufw

# Change:
# DEFAULT_FORWARD_POLICY="DROP"
# to
DEFAULT_FORWARD_POLICY="ACCEPT"

Save the file and then run:

sudo ufw reload

Creating a docker container

cd /vagrant

sudo docker build -t chrisabrams/ubuntu-node-hello .

This will create a docker container with chrisabrams as the username and ubuntu-node-hello as the container name. You can rename those to whatever you want. The . at the end means take all files in the directory and add them to the container to be built.

Running a docker container

sudo docker run -d -p 8080:8080 chrisabrams/ubuntu-node-hello

-d will run the container as a daemon. -p will bind port 8080 in docker to port 8080 in the VM.

You should now see Hello World when you run:

curl localhost:8080

Viewing the docker instance from your OS

ifconfig

Look for eth1 and then the inet addr:. That should be the network IP address that was assigned to your VM. You can then access that from your browser:

http://IPADDRESS:8080

Getting the container's logs

First, view the docker containers:

sudo docker ps

Find the CONTAINER_ID and then run:

sudo docker logs CONTAINER_ID_HERE

Additional UFW ports

If you need to open additional ports, add:

sudo ufw allow 4243/tcp

which would open port 4243.