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.

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.)