Tidied up Ubuntu installation documentation

docs/sources/installation/ubuntulinux.rst

@@ -65,32 +65,35 @@ Installation
 
 Docker is available as a Debian package, which makes installation easy.
 
+First add the Docker repository key to your local keychain. You can use the
+``apt-key`` command to check the fingerprint matches: ``36A1 D786 9245 C895 0F96
+6E92 D857 6A8B A88D 21E9``
 
 .. code-block:: bash
 
-   # Add the Docker repository key to your local keychain
-   # using apt-key finger you can check the fingerprint matches 36A1 D786 9245 C895 0F96 6E92 D857 6A8B A88D 21E9
    sudo sh -c "wget -qO- https://get.docker.io/gpg | apt-key add -"
 
-   # Add the Docker repository to your apt sources list.
+Add the Docker repository to your apt sources list, update and install the
+``lxc-docker`` package. 
+
+*You may receive a warning that the package isn't trusted. Answer yes to
+continue installation.*
+
+.. code-block:: bash
+
    sudo sh -c "echo deb http://get.docker.io/ubuntu docker main\
    > /etc/apt/sources.list.d/docker.list"
-
-   # Update your sources
    sudo apt-get update
-
-   # Install, you will see another warning that the package cannot be authenticated. Confirm install.
    sudo apt-get install lxc-docker
 
-Verify it worked
+Now verify that the installation has worked by downloading the ``ubuntu`` image
+and launching a container.
 
 .. code-block:: bash
 
-   # download the base 'ubuntu' container and run bash inside it while setting up an interactive shell
    sudo docker run -i -t ubuntu /bin/bash
 
-   # type 'exit' to exit
-
+Type ``exit`` to exit
 
 **Done!**, now continue with the :ref:`hello_world` example.
 
@@ -108,7 +111,7 @@ Ubuntu Raring already comes with the 3.8 kernel, so we don't need to install it.
 have AUFS filesystem support enabled. AUFS support is optional as of version 0.7, but it's still available as
 a driver and we recommend using it if you can.
 
-To make sure aufs is installed, run the following commands:
+To make sure AUFS is installed, run the following commands:
 
 .. code-block:: bash
 
@@ -121,36 +124,37 @@ Installation
 
 Docker is available as a Debian package, which makes installation easy.
 
-*Please note that these instructions have changed for 0.6. If you are upgrading from an earlier version, you will need
-to follow them again.*
+.. warning::
+
+    Please note that these instructions have changed for 0.6. If you are upgrading from an earlier version, you will need
+    to follow them again.
+
+First add the Docker repository key to your local keychain. You can use the
+``apt-key`` command to check the fingerprint matches: ``36A1 D786 9245 C895 0F96
+6E92 D857 6A8B A88D 21E9``
 
 .. code-block:: bash
 
-   # Add the Docker repository key to your local keychain
-   # using apt-key finger you can check the fingerprint matches 36A1 D786 9245 C895 0F96 6E92 D857 6A8B A88D 21E9
    sudo sh -c "wget -qO- https://get.docker.io/gpg | apt-key add -"
 
-   # Add the Docker repository to your apt sources list.
+Add the Docker repository to your apt sources list, update and install the
+``lxc-docker`` package.
+
+.. code-block:: bash
+
    sudo sh -c "echo deb http://get.docker.io/ubuntu docker main\
    > /etc/apt/sources.list.d/docker.list"
-
-   # update
    sudo apt-get update
-
-   # install
    sudo apt-get install lxc-docker
 
-
-Verify it worked
+Now verify that the installation has worked by downloading the ``ubuntu`` image
+and launching a container.
 
 .. code-block:: bash
 
-   # download the base 'ubuntu' container
-   # and run bash inside it while setting up an interactive shell
    sudo docker run -i -t ubuntu /bin/bash
 
-   # type exit to exit
-
+Type ``exit`` to exit
 
 **Done!**, now continue with the :ref:`hello_world` example.
 
@@ -160,8 +164,8 @@ Verify it worked
 Docker and UFW
 ^^^^^^^^^^^^^^
 
-Docker uses a bridge to manage container networking. By default, UFW
-drops all `forwarding`, thus a first step is to enable UFW forwarding:
+Docker uses a bridge to manage container networking. By default, UFW drops all
+`forwarding` traffic. As a result will you need to enable UFW forwarding:
 
 .. code-block:: bash
 
@@ -179,9 +183,9 @@ Then reload UFW:
    sudo ufw reload
 
 
-UFW's default set of rules denied all `incoming`, so if you want to be
-able to reach your containers from another host, you should allow
-incoming connections on the docker port (default 4243):
+UFW's default set of rules denies all `incoming` traffic. If you want to be
+able to reach your containers from another host then you should allow
+incoming connections on the Docker port (default 4243):
 
 .. code-block:: bash