mkschroot 0.3.4.1

Description:

mkschroot 0.3.4.1

A simple script for making schroot environments from a JSON
configuration file. The idea is to let you set up multiple schroot
images simply and quickly and to be able to check in the configuration
that makes this repeatable across many machines easily.
This first version isn’t so smart. It assumes that you’re using a 64 bit
host machine, and doesn’t check that you’re on Debian as it should (it
only uses debootstrap to build the chroot environment). It’s
probably also highly Ubuntu specific right now. To add to the fun it’s
not been very thoroughly tested yet either.
To use it you must install a couple of things:
apt-get install debootstrap schroot
pip install mkschroot

Using mkschroot
You just need to pass mkschroot a configuration file:
mkschroot ~/chroots/example.json
Don’t run with root privileges. If root access is required then sudo
rights will be requested.
If the schroot configuration has been changed then a new
configuration file will be generated. If the image doesn’t exist it will
be created and have the packages installed on it, if it does exist it
will be updated to the latest package list and package versions.
You really want to have a local apt-cacher if you’re going to be
making a lot of images.

Configuring mkschroot
The configuration file needs to be JSON. A configuration file might look
like the below:
{
"root": "/mnt/files2/chroot",
"source": "http://th.archive.ubuntu.com/ubuntu/",
"http-proxy": "http://angelo:3142/",
"base-packages": ["lsb-release", "openssh-client"],
"defaults": {
"sources": {
"universe": {}
},
"conf": {
"root-users": ["kirit"],
"users": ["kirit"]
}
},
"schroot": {
"build-lucid64": {
"release": "lucid",
"packages": [
"g++", "libbz2-dev", "libssl-dev", "python-dev", "uuid-dev",
"libboost-dev", "subversion", "git-core"
]
},
"root-ca-kirit": {
"release": "precise",
"packages": ["openssl"],
"conf": {
"personality": "linux32"
}
}
}
}
The base options are:

base-packages: Packages that are to be installed in all chroots.
defaults: Default values for individual chroot configurations.
http-proxy: A HTTP proxy (probably an apt-cache) that should be
used by debootstrap to fetch packages.
root: The directory where you want the chroots to be created in
by default (override this using the directory setting within a
chroot).
schroot: The schroot environments to be created.
source: Where the packages can be installed from. This is
required.

A chroot configuration is described by a structure like the following:
{
"release": "lucid",
"variant": "buildd",
"packages": ["g++"],
"sources": {
"universe": {}
},
"conf": {
"root-users": ["kirit'"],
"users": ["kirit"]
}
}

release: The operating system version you wish to make use of.
variant: If specified then the variant is passed to
debootstrap so that the right base image options are used. The
variant name is also used in the schroot configuration file so
that the right start up options are used when the chroot is started.
Note that some schroot options (notably fstab for buildd) won’t
work until they’re configured to match your system.
conf: The fields used for the schroot configuration file (in
/etc/schroot/chroot.d/). All fields are optional. The fields
root-users and users will have values created from the
currently logged in user. The other fields that can be here are:
description, type, personality, directory. Do read
the part about common fields though (below).
sources: Extra sources that are to be added to the chroot. See
sources below.
packages: Packages that need to be installed into the chroot
using apt-get. These are combined with the base-packages.

Note that if you change the variant of an existing image no attempt is
made to correct the packages that are installed.

Common configuration items
Generally many of the chroots that you want will share a good deal of
configuration between machines. To help with this a default schroot
configuration can be given which will then have values overridden by the
specific schroots that you request be made.
This means that the values in the defaults key will be used, then
any values in the specific schroots key will be added in, and
finally a few defaults will be generated by mkschroot.

description: The release name together with personality name.
directory: The root global option will have the schroot name
added to it.
type: Always directory.
personality: The same as the host personality (currently hard
coded to 64 bits)
‘root-users’: A list of user names. Defaults to the currently logged
in user.
‘users’: A list of user names. Defaults to the currently logged in
user.



/etc/apt/apt.conf
If the host environment has an /etc/apt/apt.conf file then it is
assumed that this should also be in the schroot environments. If the
file contents differ then the host file is copied into the schroot and
apt-get update is run within the chroot.


Sources
If other sources are needed then they can be specified at either the
defaults level or for an individual schroot. The name is used as the
component name, and this will generate a file in
/etc/apt/sources.list.d/ with the component pointing at the source.
If a source field is given than that is used, otherwise the global
source is used.
For example:
sources: {
"universe": {},
"private-example": {"source": "http://example.com/"}
}
Will generate two files, universe.list:
deb http://th.archive.ubuntu.com/ubuntu/ universe
And private-example.list`:
deb http://example.com/ private-example
Note that the value for a source component must be a JSON object, even
if empty.