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Getting started

• vagrant up --provider=virtualbox
• curl 172.17.8.100:4567

Note: or just vagrant up if you use VirtualBox by default
I use VMWare by default and so any VirtualBox boxes
require the use of the --provider flag

What?

This repository is set-up to automate the construction of a basic Ruby application that is running inside a Docker container in a Ubuntu VM.

Vim and tmux are installed inside the VM because I wanted to take advantage of the vagrant share --ssh feature for pair programming whilst having better control over my tmux windows (see this gist which explains the technique). Also take a look at the provision.sh script to see what else is happening when the VM is booting up.

Although you can just develop directly inside of the VM without any issues, I've since made it possible for you to develop outside the VM (e.g. in your host environment)...

For you to access the running application from your host machine we needed to tell the Docker daemon to run from a specific private ip (172.17.8.100). We also set-up the VM to have the same ip address. Along with some trickery in our provision.sh we're able to run the Docker CLI from the host machine and access the application running inside the VM as well.

To access the application (running on port 4567) open a web browser and visit http://172.17.8.100:4567

To use Docker simply type docker ps to see the running containers.

If you want to develop from the VM then that's fine as well, you can run vagrant ssh to enter the VM and then start using Vim and tmux (the application files are synced into the /www directory of the VM).

But if you want to use Docker from inside the VM you now have to switch to being the root user. So once inside the VM run su followed by the password Vagrant assigns to the root user (which is vagrant).

Application updates not showing?

If you make a change to the Ruby application then you'll need to restart the docker container with docker restart {container_id} or utilise a gem that reloads the application within the Docker container whenever changes to a file are detected.

Inside or out?

I've set-up the VM to allow you to develop directly from within the VM using tmux and Vim as well as from outside the VM. Choose whichever you prefer.

Because we're syncing our application directory into the VM and then mounting that VM sync'ed folder into the container as a volume, it means we can develop from the host machine as well as from within the VM (as the files changed will be synced to the VM and then passed directly through to the container).

Reptyr

reptyr is a utility for taking an existing running program and attaching it to a new terminal

• Open a program (e.g. top)
• Suspend that program (e.g. <C-z>)
• Send the program into a background process (e.g. bg)
• Detach the program from its current parent (e.g. disown top)
• Open your terminal multiplexer (e.g. tmux or screen)
• Reattach the program to your terminal multiplexer using Reptyr (e.g. reptyr $(pgrep top))

Accessing the system clipboard

When using a GUI-less version of Linux like this you wont be able to take advantage of the system clipboard inside the VM unless you use a program like XQuartz. Download and run XQuartz, then start up your VM. The Vagrantfile has been set-up to forward XQuartz onto the VM, meaning that the xclip program (installed by our provision.sh) will now work as intended.

Dotfiles

You'll notice inside the provision.sh I'm downloading and installing my own dotfiles - I would highly recommend you review the .tmux.conf, .vimrc and .vim files/folders to see what settings, key bindings and plugins I've installed for tmux and Vim. For example, I've configured tmux to have Vim style bindings for copy and paste (e.g. v to start visual selection and y to yank to the system clipboard using xclip).

Process

The steps I took to get the initial Vagrant file and box were:

• Visited https://vagrantcloud.com/ and clicked on Discover Boxes"
• Searched for "Ubuntu" and found https://vagrantcloud.com/ubuntu/boxes/trusty64
• vagrant init ubuntu/trusty64
• Modified the Vagrantfile as seen in this GitHub repository
• vagrant up --provider=virtualbox