I am working through O'Reilly's Data Visualization with Python and JavaScript and the chapter on reading and writing data uses MongoDB (among other things) as an example. I've wanted to isolate my exploratory/development software installation as much as possible. With python this is fairly easy (thanks to virtualenv), and npm can make isolating javascript installations easier, but I wanted to try and use Docker to isolate any other things I had to install so this is a first step. It's actuall a second step, since I already have a Redis container, but I didnt' take any notes when I installed it so I don't really remember doing it, and I'm going to extend the use of docker to handle all the intallations I make while reading this book so it's a first-step for this reason, at least.

Anyway, here's what to do.

First pull the mongo docker image.

docker pull mongo

To check that it's there after everything is done you can run docker images and you should see something like this.

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
mongo               latest              282fd552add6        2 days ago          336.1 MB
redis               latest              be9c5a746699        5 weeks ago         184.9 MB

In this case I want the connection to Mongo DB to be available so I'm going to bind its local port (27017) to my host. I'm also going mount my local data file in the container so it will save its data my local folder.

docker run --name mongo -p 27017:27017 -v $PWD/data:/data/db -d mongo

The --name flag gives the name that you'll see if you run docker ps to see the running containers. -p 27017:27017 makes it available to my host machine via localhost:27017. -v $PWD/data:/data/db mounts the data folder in the directory where I ran the docker command inside the container at /data/db. -d says to run it as a daemon. Finally the last argument mongo identifies the image for the container.

At this point MongoDb is accessible from my host machine, so, using pymongo I can connect to it using something like this.

from pymongo import MongoClient

client = MongoClient('localhost', 27017)

And that's it.