packer-builder-lxc

Lxc builder for Packer, with working provisioning.

OS Support

As building platform only Linux is supported, at this point Ubuntu and Debian is tested. Please consult your lxc templates so you can pass the right parameters. All OSes should be buildable if they are supported by your lxc templates.

Debian

Wheezy is supported with lxc 1.0.0. An older version is shipped, with a broken lxc-attach command, so it's not supported. A backport deb can be created easily following this guide. Debian does not ship network support by default for lxc, you have to configure it manually. See the vagrant-lxc wiki for a detailed howto.

If you want to do anything during provisioning that needs network access, you'll need to edit /etc/lxc/default.conf to bring the network up on new containers:

lxc.network.type=veth
lxc.network.link=lxcbr0
lxc.network.flags=up

If your containers do not get an ip address from dhcp you need to turn off checksum offloading on the bridge:

/sbin/ethtool -K lxcbr0 tx off

If you're done with all of these you are ready to build containers on wheezy!

Ubuntu

Everything above saucy should be supported (saucy is tested). The default configuration is good to go!

If your containers do not get an ip address from dhcp you need to turn off checksum offloading on the bridge:

/sbin/ethtool -K lxcbr0 tx off

Building from source

Install golang-go:

sudo apt-get install golang-go

Install dependencies:

go get github.com/mitchellh/gox
go get github.com/mitchellh/go-fs
go get github.com/mitchellh/multistep
go get github.com/ustream/packer-builder-lxc

Go to the source directory, usually it is in ~/gopath/src/github.com/ustream/packer-builder-lxc

cd ~/gopath/src/github.com/ustream/packer-builder-lxc

Build binary file with gox for desired platform:

gox -os=linux -arch=amd64 -output=pkg/{{.OS}}_{{.Arch}}/packer-builder-lxc

Copy output binary file to desired location, for example to /vagrant/packer:

cp pkg/linux_amd64/packer-builder-lxc /vagrant/packer

Installation

Add the executable to your .packerconfig Core Config, if you use custom path like /vagrant/packer/packer-builder-lxc:

{
  "builders": {
    "lxc": "/vagrant/packer/packer-builder-lxc"
  }
}

From now you should be able to use lxc in packer builders.

Example packer templates

Building wheezy on saucy:

{
  "builders": [
    {
      "type": "lxc",
      "config_file": "lxc/config",
      "template_name": "debian",
      "template_environment_vars": [
        "MIRROR=http://http.debian.net/debian/",
        "SUITE=wheezy"
      ],
      "target_runlevel": 3
    }
  ]
}

The config_file is an lxc config file which will be bundled with the machine. You can create your own or just grab the debian or ubuntu from vagrant-lxc-base-boxes.

Building wheezy on wheezy:

{
  "builders": [
    {
      "type": "lxc",
      "config_file": "lxc/config",
      "template_name": "debian",
      "template_parameters": ["--arch", "amd64", "--release", "wheezy"],
      "template_environment_vars": [
        "MIRROR=http://http.debian.net/debian/"
      ],
      "target_runlevel": 3
    }
  ],
  "provisioners": [
    {
      "type": "shell",
      "only": ["lxc"],
      "environment_vars": [
        "DISTRIBUTION=debian",
        "RELEASE=wheezy"
      ],
      "scripts": [
        "scripts/lxc/base.sh",
        "scripts/lxc/vagrant-lxc-fixes.sh"
      ]
    }
  ],
  "post-processors": [
    {
      "type": "compress",
      "output": "output-vagrant/wheezy64-lxc.box"
    }
  ],
}

Note the differences in template parameters/envvars!

Vagrant publishing

The output artifact can be compressed with the compress publisher to create a working vagrant box (see example).