add mongodb image example

docs/sources/examples/mongodb.rst

@@ -0,0 +1,98 @@
+:title: Building a Docker Image with MongoDB
+:description: How to build a Docker image with MongoDB pre-installed
+:keywords: docker, example, package installation, networking, mongodb
+
+.. _mongodb_image:
+
+Building an Image with MongoDB
+==============================
+
+.. include:: example_header.inc
+
+The goal of this example is to show how you can build your own
+docker images with MongoDB preinstalled. We will do that by
+constructing a Dockerfile that downloads a base image, adds an
+apt source and installs the database software on Ubuntu.
+
+Creating a ``Dockerfile``
++++++++++++++++++++++++++
+
+Create an empty file called ``Dockerfile``:
+
+.. code-block:: bash
+
+    touch Dockerfile
+
+Next, define the parent image you want to use to build your own image on top of.
+Here, we’ll use `CentOS <https://index.docker.io/_/ubuntu/>`_ (tag: ``latest``)
+available on the `docker index`_:
+
+.. code-block:: bash
+
+    FROM    ubuntu:latest
+
+Since we want to be running the latest version of MongoDB we'll need to add the
+10gen repo to our apt sources list.
+
+.. code-block:: bash
+
+    # Add 10gen official apt source to the sources list
+    RUN apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
+    RUN echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' | tee /etc/apt/sources.list.d/10gen.list
+
+Then, we don't want Ubuntu to complain about init not being available so we'll
+divert /sbin/initctl to /bin/true so it thinks everything is working.
+
+.. code-block:: bash
+
+    # Hack for initctl not being available in Ubuntu
+    RUN dpkg-divert --local --rename --add /sbin/initctl
+    RUN ln -s /bin/true /sbin/initctl
+
+Afterwards we'll be able to update our apt repositories and install MongoDB
+
+.. code-block:: bash
+
+    # Install MongoDB
+    RUN apt-get update
+    RUN apt-get install mongodb-10gen
+
+To run MongoDB we'll have to create the default data directory (because we want it to
+run without needing to provide a special configuration file)
+
+.. code-block:: bash
+
+    # Create the MongoDB data directory
+    RUN mkdir -p /data/db
+
+Finally, we'll expose the standard port that MongoDB runs on (27107)
+
+.. code-block:: bash
+
+    EXPOSE 27017
+
+Now, lets build the image which will go through the ``Dockerfile`` we made and
+run all of the commands.
+
+.. code-block:: bash
+
+    docker build -t <yourname>/mongodb .
+
+Now you should be able to run ``mongod`` as a daemon and be able to connect on
+the local port!
+
+.. code-block:: bash
+
+    # Regular style
+    MONGO_ID=$(docker run -d <yourname>/mongodb mongod)
+
+    # Lean and mean
+    MONGO_ID=$(docker run -d <yourname>/mongodb mongod --noprealloc --smallfiles)
+
+    # Check the logs out
+    docker logs $MONGO_ID
+
+    # Connect and play around
+    mongo --port <port you get from `docker ps`>
+
+Sweet!