@@ -4,10 +4,12 @@ page_keywords: Docker, Docker documentation, requirements, linux, centos, epel,

 # CentOS

-While the Docker package is provided by default as part of CentOS-7, 

-it is provided by a community repository for CentOS-6. Please note that 

-this changes the installation instructions slightly between versions. 

- 

+While the Docker package is provided by default as part of CentOS-7,

+it is provided by the EPEL repository for CentOS-6. Please note that

+this changes the installation instructions slightly between versions. If you

+need the latest version, you can always use the latest binary which works on

+kernel 3.8 and above.

+

 These instructions work for CentOS 6 and later. They will likely work for

 other binary compatible EL6 distributions such as Scientific Linux, but

 they haven't been tested.

@@ -25,6 +27,30 @@ simply run the following command.

     $ sudo yum install docker

+### Manual installation of latest version

+

+While using a package is the recommended way of installing Docker,

+the above package might not be the latest version. If you need the latest

+version, [you can install the binary directly](

+https://docs.docker.com/installation/binaries/).

+

+When installing the binary without a package, you may want

+to integrate Docker with systemd. For this, simply install the two unit files

+(service and socket) from [the github

+repository](https://github.com/docker/docker/tree/master/contrib/init/systemd)

+to `/etc/systemd/system`.

+

+### FirewallD

+

+CentOS-7 introduced firewalld, which is a wrapper around iptables and can

+conflict with Docker.

+

+When firewalld is started or restarted it will remove the `DOCKER` chain

+from iptables, preventing Docker from working properly.

+

+When using systemd, firewalld is started before Docker, but if you

+start or restart firewalld  after Docker, you will have to restart the Docker daemon.

+

 ## Installing Docker - CentOS-6

 Please note that this for CentOS-6, this package is part of [Extra Packages

 for Enterprise Linux (EPEL)](https://fedoraproject.org/wiki/EPEL), a community effort