Fig is a project from [Orchard](https://orchardup.com). [Follow us on Twitter](https://twitter.com/orchardup) to keep up to date with Fig and other Docker news.
Let's get a basic Python web app running on Fig. It assumes a little knowledge of Python, but the concepts should be clear if you're not familiar with it.
First, install Docker. If you're on OS X, you can use [docker-osx](https://github.com/noplay/docker-osx):
Docker has guides for [Ubuntu](http://docs.docker.io/en/latest/installation/ubuntulinux/) and [other platforms](http://docs.docker.io/en/latest/installation/) in their documentation.
Next, install Fig:
$ sudo pip install -U fig
(This command also upgrades Fig when we release a new version. If you don’t have pip installed, try `brew install python` or `apt-get install python-pip`.)
You'll want to make a directory for the project:
$ mkdir figtest
$ cd figtest
Inside this directory, create `app.py`, a simple web app that uses the Flask framework and increments a value in Redis:
return 'Hello World! I have been seen %s times.' % redis.get('hits')
if __name__ == "__main__":
app.run(host="0.0.0.0", debug=True)
```
We define our Python dependencies in a file called `requirements.txt`:
flask
redis
And we define how to build this into a Docker image using a file called `Dockerfile`:
FROM stackbrew/ubuntu:13.10
RUN apt-get -qq update
RUN apt-get install -y python python-pip
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt
EXPOSE 5000
CMD python app.py
That tells Docker to create an image with Python and Flask installed on it, run the command `python app.py`, and open port 5000 (the port that Flask listens on).
We then define a set of services using `fig.yml`:
web:
build: .
ports:
- 5000:5000
volumes:
- .:/code
links:
- redis
redis:
image: orchardup/redis
This defines two services:
-`web`, which is built from `Dockerfile` in the current directory. It also says to forward the exposed port 5000 on the container to port 5000 on the host machine, connect up the Redis service, and mount the current directory inside the container so we can work on code without having to rebuild the image.
-`redis`, which uses the public image [orchardup/redis](https://index.docker.io/u/orchardup/redis/).
Now if we run `fig up`, it'll pull a Redis image, build an image for our own code, and start everything up:
$ fig up
Pulling image orchardup/redis...
Building web...
Starting figtest_redis_1...
Starting figtest_web_1...
figtest_redis_1 | [8] 02 Jan 18:43:35.576 # Server started, Redis version 2.8.3
figtest_web_1 | * Running on http://0.0.0.0:5000/
Open up [http://localhost:5000](http://localhost:5000) in your browser (or [http://localdocker:5000](http://localdocker:5000) if you're using [docker-osx](https://github.com/noplay/docker-osx)) and you should see it running!
If you want to run your services in the background, you can pass the `-d` flag to `fig up` and use `fig ps` to see what is currently running:
figtest_web_1 /bin/sh -c python app.py Up 5000->5000/tcp
`fig run` allows you to run one-off commands for your services. For example, to see what environment variables are available to the `web` service:
$ fig run web env
See `fig --help` other commands that are available.
If you started Fig with `fig up -d`, you'll probably want to stop your services once you've finished with them:
$ fig stop
That's more-or-less how Fig works. See the reference section below for full details on the commands, configuration file and environment variables. If you have any thoughts or suggestions, [open an issue on GitHub](https://github.com/orchardup/fig) or [email us](mailto:hello@orchardup.com).