# 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 those modules to deploy salt and re-attach to master.

  > - `lxc runner`

  > - `lxc module`

  > - `seed`

## 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 use `lxc.init` via the `lxc.cloud_init_interface` and seeds the minion via `seed.mkconfig`.

You can provide to those lxc VMs a profile and a network profile like if you were directly using the minion module.

Order of operation:

- Create the LXC container 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

- 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
      driver: lxc

Note

Changed in version 2015.8.0.

The `provider` parameter in cloud provider definitions was renamed to `driver`. This change was made to avoid confusion with the `provider` parameter that is used in cloud profile definitions. Cloud provider definitions now use `driver` to refer to the Salt cloud module that provides the underlying functionality to connect to a cloud host, while cloud profiles continue to use `provider` to refer to provider configurations that you define.

## Profile configuration

Please read LXC Management with Salt before anything else. And specially Profiles.

Here are the options to configure your containers:

> target

>   Host minion id to install the lxc Container into

> lxc_profile

>   Name of the profile or inline options for the LXC vm creation/cloning, please see Container Profiles.

> network_profile

>   Name of the profile or inline options for the LXC vm network settings, please see Network Profiles.

> nic_opts

>   Totally optional. Per interface new-style configuration options mappings which will override any profile default option:

>       eth0: {'mac': '00:16:3e:01:29:40',
>                     'gateway': None, (default)
>                     'link': 'br0', (default)
>                     'gateway': None, (default)
>                     'netmask': '', (default)
>                     'ip': '22.1.4.25'}}

> password

>   password for root and sysadmin users

> dnsservers

>   List of DNS servers to use. This is optional.

> minion

>   minion configuration (see Minion Configuration in Salt Cloud)

> bootstrap_delay

>   specify the time to wait (in seconds) between container creation and salt bootstrap execution. It is useful to ensure that all essential services have started before the bootstrap script is executed. By default there's no wait time between container creation and bootstrap unless you are on systemd where we wait that the system is no more in starting state.

> bootstrap_shell

>   shell for bootstraping script (default: /bin/sh)

> script

>   defaults to salt-boostrap

> script_args

>   arguments which are given to the bootstrap script. the {0} placeholder will be replaced by the path which contains the minion config and key files, eg:

>       script_args="-c {0}"

Using profiles:

    # Note: This example would go in /etc/salt/cloud.profiles or any file in the
    # /etc/salt/cloud.profiles.d/ directory.
    devhost10-lxc:
      provider: devhost10-lxc
      lxc_profile: foo
      network_profile: bar
      minion:
        master: 10.5.0.1
        master_port: 4506

Using inline profiles (eg to override the network bridge):

    devhost11-lxc:
      provider: devhost10-lxc
      lxc_profile:
        clone_from: foo
      network_profile:
        etho:
          link: lxcbr0
      minion:
        master: 10.5.0.1
        master_port: 4506

Using a lxc template instead of a clone:

    devhost11-lxc:
      provider: devhost10-lxc
      lxc_profile:
        template: ubuntu
        # options:
        #   release: trusty
      network_profile:
        etho:
          link: lxcbr0
      minion:
        master: 10.5.0.1
        master_port: 4506

Static ip:

    # Note: This example would go in /etc/salt/cloud.profiles or any file in the
    # /etc/salt/cloud.profiles.d/ directory.
    devhost10-lxc:
      provider: devhost10-lxc
      nic_opts:
        eth0:
          ipv4: 10.0.3.9
      minion:
        master: 10.5.0.1
        master_port: 4506

DHCP:

    # Note: This example would go in /etc/salt/cloud.profiles or any file in the
    # /etc/salt/cloud.profiles.d/ directory.
    devhost10-lxc:
      provider: devhost10-lxc
      minion:
        master: 10.5.0.1
        master_port: 4506

## Driver Support

- Container creation

- Image listing (LXC templates)

- Running container information (IP addresses, etc.)