Behavior-Driven Docker Development

This repository demonstrates how to use cucumber and behavior-driven development to orchestrate docker containers into a running 3-tiered application. It also can be used to quickly get a rails development environment running for a specific project.

Once you have all the pre-requisites installed, starting up a rails app is as simple as

$ fig up -d

$ vagrant up --provision

And then you can visit http://localhost:8080 or http://localhost:3000 on your host machine to access the website.

But the real power of this setup is that we can develop new docker containers in a test-driven manner.

Pre-Requisites - Docker & Fig

Running Docker natively

This is the preferred approach. If you're running linux natively then just install Docker and Fig natively.

Running Docker on Boot2Docker (OSX)

Follow the instructions to install Boot2Docker and then install Fig

Running via Vagrant and Virtualbox

If you're on Windows, or can't get docker installed on your platform, we've provided a Vagrant setup that you can use. Install Virtualbox >= 4.3.20 as well as Vagrant >= 1.6.5 for your platform. Then get up and running:

$ vagrant up
$ vagrant provision

Once up and running, you'll run the fig commands from inside the vagrant image:

$ vagrant ssh
vagrant@vagrant:~$ cd docker-bdd
vagrant@vagrant:~/docker-bdd$ fig build
vagrant@vagrant:~/docker-bdd$ fig up -d
vagrant@vagrant:~/docker-bdd$ cucumber

On subsequent runs, since there won't be huge downloads, you can just run:

$ vagrant ssh
vagrant@vagrant:~$ cd docker-bdd
vagrant@vagrant:~/docker-bdd$ cucumber

Testing Dependencies

In addition to installing docker and fig, you'll need to have Cucumber installed in order to run the tests.

$ sudo apt-get install cucumber

Or,

install ruby (e.g. via rvm or a system package)
install cucumber
```
  $ gem install cucumber
```

Running the Tests

The tests ensure that the fig cluster is running, so running them is as simple as running cucumber. You can also just run a specific test:

$ cucumber features/web.feature

If this is your first time running this, then grab a cup of coffeen and enjoy a nice 10-15 minute wait, as the base docker images are downloaded, and then custom images are built and run. Subsequent executions will be much faster.

Starting the cluster

Running the tests also accomplishes this, but if you're too lazy to run the tests:

$ fig run -d

When you make a change and want to rebuild a docker container

Again, running the tests accomplishes this, but if you want to do it manually:

$ fig build

Using a rails-enabled dev environment

We've set up the dev service to also serve as a development environment, wher eyou can issue commands like rails g scaffold. Since the files in this environment are the same files that you have locally, you can edit in your native environment, and use this environment for doing things like running tests, generating files, testing out dependencies, etc.

$ fig run dev

Viewing Logs

This is a really nice feature of fig, providing a combined output from all the running services.

$ fig logs

This will show logs as they come in. Use Ctrl+C to quit.

Troubleshooting

Couldn't connect to Docker daemon at http+unix://var/run/docker.sock - is it running?
- Either add your user to the docker group (preferred), or use sudo fig and sudo cucumber for the commands.
vagrant up hangs for me
- Try launching the virtual machine via VirtualBox directly to see if there are any errors.
I'm on a 32-bit system but the virtualbox/docker images are 64-bit
- We tried getting this to work with a 32-bit vagrant image, but ran into exec format error issues. A 32-bit fork of this project would be nice.
I see a bunch of errors in the output saying stdin: is not a tty
- These can safely be ignored, but if you can resolve the issue, please submit a pull request
I get failures when I run cucumber, but when I run the failing commands manually, they pass.
- This may be due to the tests running before the server is fully started. Currently, there's a hack in fig_steps.rb to just sleep for 10 seconds after running fig up, but this may not be suitable for all environments.

Thanks

Thanks to the great work being done on Docker and Fig!

jemiller1963 / docker-bdd