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Getting Started With LXC¶

The LXC module is designed to install Salt in an LXC container on a controlled and possibly remote minion.

In other words, Salt will connect to a minion, then from that minion:

Provision and configure a container for networking access
Use saltify to deploy salt and re-attach to master

Limitations¶

You can only act on one minion and one provider at a time.
Listing images must be targeted to a particular LXC provider (nothing will be outputted with all)

Operation¶

Salt's LXC support does not use lxc.init. This enables it to tie minions to a master in a more generic fashion (if any masters are defined) and allows other custom association code.

Order of operation:

Create the LXC container using the LXC execution module on the desired minion (clone or template)
Change LXC config options (if any need to be changed)
Start container
Change base passwords if any
Change base DNS configuration if necessary
Wait for LXC container to be up and ready for ssh
Test SSH connection and bailout in error
Via SSH (with the help of saltify), upload deploy script and seeds, then re-attach the minion.

Provider configuration¶

Here is a simple provider configuration:

# Note: This example goes in /etc/salt/cloud.providers or any file in the
# /etc/salt/cloud.providers.d/ directory.
devhost10-lxc:
  target: devhost10
  provider: lxc

Profile configuration¶

Here are the options to configure your containers:

``target``
    Host minion id to install the lxc Container into
``profile``
    Name of the profile containing the LXC configuration

Container creation/clone options:
    Create a container by cloning:
        ``from_container``
            Name of an original container using clone
        ``snapshot``
            Do we use snapshots on cloned filesystems
    Create a container from scratch using an LXC template:
        image
            template to use
        backing
            Backing store type (None, lvm, brtfs)
        lvname
            LVM logical volume name, if any
        fstype
            Type of filesystem
size
    Size of the containera (for brtfs, or lvm)
vgname
    LVM Volume Group name, if any
users
    Names of the users to be pre-created inside the container
ssh_username
    Username of the SSH systems administrator inside the container
sudo
    Do we use sudo
ssh_gateway
    if the minion is not in your 'topmaster' network, use
    that gateway to connect to the lxc container.
    This may be the public ip of the hosting minion
ssh_gateway_key
    When using gateway, the ssh key of the gateway user (passed to saltify)
ssh_gateway_port
    When using gateway, the ssh port of the gateway (passed to saltify)
ssh_gateway_user
    When using gateway, user to login as via SSH (passed to saltify)
password
    password for root and sysadmin (see "users" parameter above)
mac
    mac address to assign to the container's network interface
ip
    IP address to assign to the container's network interface
netmask
    netmask for the network interface's IP
bridge
    bridge under which the container's network interface will be enslaved
dnsservers
    List of DNS servers to use--this is optional.  If present, DNS
    servers will be restricted to that list if used
lxc_conf_unset
    Configuration variables to unset in this container's LXC configuration
lxc_conf
    LXC configuration variables to add in this container's LXC configuration
minion
    minion configuration (see :doc:`Minion Configuration in Salt Cloud </topics/cloud/config>`)

# Note: This example would go in /etc/salt/cloud.profile or any file in the
# /etc/salt/cloud.profile.d/ directory.
devhost10-lxc:
  provider: devhost10-lxc
  from_container: ubuntu
  backing: lvm
  sudo: True
  size: 3g
  ip: 10.0.3.9
  minion:
    master: 10.5.0.1
    master_port: 4506
  lxc_conf:
    - lxc.utsname: superlxc

Driver Support¶

Container creation
Image listing (LXC templates)
Running container informations (IP addresses, etc.)