Packer-Cn/website/source/docs/builders/lxc.html.md

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description: | The lxc Packer builder builds containers for lxc1. The builder starts an LXC container, runs provisioners within this container, then exports the container as a tar.gz of the root file system. layout: docs page_title: LXC Builder ...

LXC Builder

Type: lxc

The lxc Packer builder builds containers for lxc1. The builder starts an LXC container, runs provisioners within this container, then exports the container as a tar.gz of the root file system.

The LXC builder requires a modern linux kernel and the lxc or lxc1 package. This builder does not work with LXD.

Note to build Centos images on a Debian family host, you will need the yum package installed.

Some provisioners such as ansible-local get confused when running in a container of a different family. E.G. it will attempt to use apt-get to install packages, when running in a Centos container if the parent OS is Debian based.

Basic Example

Below is a fully functioning example.

{
  "builders": [
    {
      "type": "lxc",
      "name": "lxc-trusty",
      "config_file": "/tmp/lxc/config",
      "template_name": "ubuntu",
      "template_environment_vars": [
        "SUITE=trusty"
      ]
    },
    {
      "type": "lxc",
      "name": "lxc-xenial",
      "config_file": "/tmp/lxc/config",
      "template_name": "ubuntu",
      "template_environment_vars": [
        "SUITE=xenial"
      ]
    },
    {
      "type": "lxc",
      "name": "lxc-jessie",
      "config_file": "/tmp/lxc/config",
      "template_name": "debian",
      "template_environment_vars": [
        "SUITE=jessie"
      ]
    },
    {
      "type": "lxc",
      "name": "lxc-centos-7-x64",
      "config_file": "/tmp/lxc/config",
      "template_name": "centos",
      "template_parameters": [
        "-R","7",
        "-a","x86_64"
       ],
    }
  ]
}

Configuration Reference

Required:

• config_file (string) - The path to the lxc configuration file.

• template_name (string) - The LXC template name to use.

• template_environment_vars (array of strings) - Environmental variables to use to build the template with.

Optional:

• target_runlevel (int) - The minimum run level to wait for the container to reach. Note some distributions (Ubuntu) simulate run levels and may report 5 rather than 3.

• output_directory (string) - The directory in which to save the exported tar.gz. Defaults to output-<BuildName> in the current directory.

• container_name (string) - The name of the LXC container. Usually stored in /var/lib/lxc/containers/<container_name>. Defaults to packer-<BuildName>.

• command_wrapper (string) - Allows you to specify a wrapper command, such as ssh so you can execute packer builds on a remote host. Defaults to Empty.

• init_timeout (string) - The timeout in seconds to wait for the the container to start. Defaults to 20 seconds.

• template_parameters (array of strings) - Options to pass to the given lxc-template command, usually located in /usr/share/lxc/templates/lxc-<template_name>``. Note: This gets passed as ARGV to the template command. Ensure you have an array of strings, as a single string with spaces probably won't work. Defaults to []`.