simhaonline / lxdfile

A Dockerfile-like file format for LXD containers

lxdfile

A Dockerfile-like file format for LXD containers.

Manage LXD containers using a Dockerfile-like file format, with support to store metadata.

Installing

Download the latest release, or use

stack build
stack exec lxdfile -- -h

Usage

Example lxdfiles can be found in lxdfile-examples.

Using lxdfiles to power LXD containers involves two steps:

1. Build the reusable image using lxdfile build
2. Launch a container using a prebuilt image using lxdfile launch

Building images

Take for example the gogs example.

Running lxdfile build gogs will create an image in your local LXD image repository

$ lxc image list local:
+-------------------------+--------------+--------+---------------------------------------+--------+----------+------------------------------+
|          ALIAS          | FINGERPRINT  | PUBLIC |              DESCRIPTION              |  ARCH  |   SIZE   |         UPLOAD DATE          |
+-------------------------+--------------+--------+---------------------------------------+--------+----------+------------------------------+
| gogs                    | 6199407c377b | no     | Gogs - Go Git Service                 | x86_64 | 177.56MB | Nov 14, 2016 at 1:56pm (UTC) |
+-------------------------+--------------+--------+---------------------------------------+--------+----------+------------------------------+
| ubuntu/yakkety (3 more) | 16b6d53f6dd1 | no     | Ubuntu yakkety amd64 (20161114_03:49) | x86_64 | 80.20MB  | Nov 14, 2016 at 1:44pm (UTC) |
+-------------------------+--------------+--------+---------------------------------------+--------+----------+------------------------------+

Launching containers

You can launch containers using lxdfile launch, e.g. lxdfile launch gogs gogs.

To configure launched containers, you can use init scripts.

A possible use of init scripts is to configure the network. You can pass multiple init scripts to lxdfile launch using the -i flag. They will be executed in the order they are passed on the command line.

$ cat configure-network.lxdfile
RUN echo "iface lan inet dhcp" > /etc/network/interfaces
RUN chmod 0600 /etc/network/interfaces

$ lxdfile launch gogs gogs -i configure-network

These configuration scripts can be container-specific or reusable for multiple images. They should be included in source control.

Metadata

Container and image metadata is stored in /etc/lxdfile. It contains JSON representations of the used lxdfile and the used init scripts.