Kernel Requirements
===================


If you want to have a full working CRUX+Docker system you will need to rebuild your kernel with the following options enabled:

Networking:

- CONFIG_BRIDGE
- CONFIG_NETFILTER_XT_MATCH_ADDRTYPE
- CONFIG_NF_NAT
- CONFIG_NF_NAT_IPV4
- CONFIG_NF_NAT_NEEDED

LVM:

- CONFIG_BLK_DEV_DM
- CONFIG_DM_THIN_PROVISIONING
- CONFIG_EXT4_FS

Namespaces:
- CONFIG_NAMESPACES
- CONFIG_UTS_NS
- CONFIG_IPC_NS
- CONFIG_UID_NS
- CONFIG_PID_NS
- CONFIG_NET_NS

Cgroups:

- CONFIG_CGROUPS

Cgroups Controllers (*optional but highly recommended*):

- CONFIG_CGROUP_CPUACCT
- CONFIG_BLK_CGROUP
- CONFIG_MEMCG
- CONFIG_MEMCG_SWAP

You may check your kernel configuration by running the provided ``test_kernel_config.sh`` script against your kernel configuration:

::
    
    ./test_kernel_config.sh /usr/src/linux/.config
         

Other Requirements
==================


You **must** have the following ``cgroup`` mount point mounted:

::
    
    none               /cgroup       cgroup    defaults               0      0
    

Storage Backends
================

Docker comes with three main Storage Backends:

- AUFS (*requires AUFS kernel/patches*)
- devmapper
- btrfs

It is recommended you use the devmapper or btrfs backend (Default: devmapper).

To use the ``btrfs`` backend edit ``/etc/docker.conf`` and modify the ``DOCKER_OPTS`` with:

::
    
    DOCKER_OPTS="-s btrfs"
    

Docker Client
=============

The provided Docker rc script changes the group ownership of the ``/var/run/socker.sock`` UNIX Socket to ``docker``.

Add yourself to this group if you wish to access the Docker daemon on localhost via UNIX Socker.