cdist/docs/web/cdist.mdwn

[[!meta title="cdist - usable configuration management"]]

     
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[[!toc levels=3]]

## Introduction

cdist is a usable configuration management system. It adheres to
the KISS principle and is being used in small up to enterprise grade
environments.
cdist is an alternative to other configuration management systems like
[cfengine](http://www.cfengine.org/),
[bcfg2](http://trac.mcs.anl.gov/projects/bcfg2),
[chef](http://wiki.opscode.com/display/chef/)
and [puppet](http://www.puppetlabs.com/).
But cdist ticks differently, here is the feature set that makes it unique: 

[[!table  data="""
Keywords | Description
Simplicity | There is only one type to extend cdist called ***type***
Design | Type and core cleanly seperated
Design | Sticks completly to the KISS (keep it simple and stupid) paradigma
Design | Meaningful error messages - do not lose time debugging error messages
Design | Consistency in behaviour, naming and documentation
Design | No surprise factor: Only do what is obviously clear, no magic
Design | Define target state, do not focus on methods or scripts
Design | Push architecture: Instantly apply your changes
Small core | cdist's core is very small - less code, less bugs
Fast development | Focus on straightforwardness of type creation is a main development objective
Fast development | Batteries included: A lot of requirements can be solved using standard types
Modern Programming Language | cdist is written in Python
Requirements, Scalability | No central server needed, cdist operates in push mode and can be run from any computer
Requirements, Scalability, Upgrade | cdist only needs to be updated on the master, not on the target hosts
Requirements, Security | Uses well-know [SSH](http://www.openssh.com/) as transport protocol
Requirements, Simplicity | Requires only shell and SSH server on the target
UNIX | Reuse of existing tools like cat, find, mv, ...
UNIX, familar environment, documentation | Is available as manpages and HTML
UNIX, simplicity, familar environment | cdist is configured in POSIX shell
"""]]

### Documentation

The cdist documentation is included as manpages in the distribution.  
You can browse the documentation online as well:

 * [latest version](man/latest)
 * [all versions (>= 2.0.4)](man)

### OS support

cdist was tested or is know to run on at least

 * [Archlinux](http://www.archlinux.org/)
 * [Debian](http://www.debian.org/)
 * [CentOS](http://www.centos.org/)
 * [Fedora](http://fedoraproject.org/)
 * [Gentoo](http://www.gentoo.org/)
 * [Mac OS X](http://www.apple.com/macosx/)
 * [OpenBSD](http://www.openbsd.org)
 * [Redhat](http://www.redhat.com/)
 * [Ubuntu](http://www.ubuntu.com/)
 * [XenServer](http://www.citrix.com/xenserver/)


## Requirements

### Server

 * A posix like shell
 * Python (>= 3.2 required)
 * SSH client
 * Asciidoc (for building the manpages)

### Client ("target host")

 * A posix like shell
 * SSH server


## Installation

### Preparation

Ensure you have Python 3.2 installed on the machine you use to **deploy to the targets**
(the ***source host***).

#### Archlinux

Archlinux already has python >= 3.2, so you only need to do:

    pacman -S python

#### CentOS

See the "From source" section

#### Debian

For Debian >= wheezy:

    aptitude install python3

On squeeze you can add following line in **/etc/apt/sources.list**

  deb http://ftp.debian.org/debian wheezy main

And add pinning entry in **/etc/apt/preferences.d/wheezy**:

  Package: *
  Pin: release n=wheezy
  Pin-Priority: 1

Please be aware that both **openssh-server** and **openssh-client** might be
removed on **python3.2** installation. You surely want to reinstall them:

  apt-get install -t wheezy openssh-server openssh-client

For older Debian versions, installing python 3.2 manually is required.


#### Fedora

For Fedora >= 15:

    yum install python3

#### FreeBSD

For the port:

    cd /usr/ports/lang/python32/ && make install clean

For the package:

    pkg_add -r python32

#### Gentoo

Gentoo only provides python 3.2 in testing packages (http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=3&chap=3).
If you want to ensure nothing breaks you must set back the python version to what was default before.

    emerge -av =python-3.2.2 --autounmask-write
    emerge -av =python-3.2.2
    eselect python list
    eselect python list set python3.2

#### Max OS X

You can choose between Homebrew and Macports, either way works:

[Homebrew](http://mxcl.github.com/homebrew/) variant:

    brew install python3

[Macports](http://www.macports.org/install.php) variant:

    port install python32
    ln -s /opt/local/bin/python3.2 /opt/local/bin/python3

#### From Source

For those operating systems not yet support Python 3.2:

    pyversion=3.2.3
    wget http://www.python.org/ftp/python/$pyversion/Python-${pyversion}.tar.bz2
    tar xvfj Python-${pyversion}.tar.bz2
    cd Python-${pyversion}
    ./configure
    make
    sudo make install

This installs python 3.2 to /usr/local/bin. Ensure this directory is in
your PATH environment variable.


### Get cdist

You can clone cdist from git, which gives you the advantage of having
a version control in place for development of your own stuff as well.
To install cdist, execute the following commands:

    git clone git://git.schottelius.org/cdist
    cd cdist
    export PATH=$PATH:$(pwd -P)/bin

    # If you want the manpages
    ./build man
    export MANPATH=$MANPATH:$(pwd -P)/doc/man


### Available versions

There are at least the following branches available:

 * Development: master
 * 2.0: Python rewrite of cdist core [stable branch]

Old versions:

 * 1.7: Bugfixes, cleanups, new type and explorer rename
 * 1.6: New types, cleaned up \_\_package* types, internal cleanup
 * 1.5: Focus on object orientation instead of global stage orientation
 * 1.4: Support for redefiniton of objects (if equal)
 * 1.3: Support for local and remote code execution (current stable)
 * 1.2: Dependencies supported
 * 1.1: \_\_file to \_\_file, \_\_directory, \_\_link migration
 * 1.0: First official release

Other branches may be available for features or bugfixes, but they
may vanish at any point. To select a specific branch use

    # Generic code
    git checkout -b <name> origin/<name>
    
    # Stay on a specific version
    version=2.0
    git checkout -b $version origin/$version

### Mirrors

 * git://github.com/telmich/cdist.git ([github](https://github.com/telmich/cdist))
 * git://git.code.sf.net/p/cdist/code ([sourceforge](https://sourceforge.net/p/cdist/code))

## Update

To upgrade cdist in the current branch use

    git pull

    # Also update the manpages
    ./build man
    export MANPATH=$MANPATH:$(pwd -P)/doc/man

If you stay on a version branche (i.e. 1.0, 1.1., ...), nothing should break.
The master branch on the other hand is the development branch and may not be
working, break your setup or eat the tree in your garden.

### Upgrading from 1.7 to 2.0

* Ensure python (>= 3.2) is installed on the server
* Use "cdist config host" instead of "cdist-deploy-to host"
* Use "cdist config -p host1 host2" instead of "cdist-mass-deploy"
* Use "cdist banner" for fun
* Use **\_\_object_fq** instead of **\_\_self** in manifests

### Upgrading from 1.6 to 1.7

* If you used the global explorer **hardware_type**, you need to change
  your code to use **machine** instead.

### Upgrading from 1.5 to 1.6

* If you used **\_\_package_apt --preseed**, you need to use the new
  type **\_\_debconf_set_selections** instead.
* The **\_\_package** types accepted either --state deinstalled or
  --state uninstaaled. Starting with 1.6, it was made consistently
  to --state removed.

### Upgrading from 1.3 to 1.5

No incompatiblities.

### Upgrading from 1.2 to 1.3

Rename **gencode** of every type to **gencode-remote**.

### Upgrading from 1.1 to 1.2

No incompatiblities.

### Upgrading from 1.0 to 1.1

In 1.1 the type **\_\_file** was split into **\_\_directory**, **\_\_file** and
**\_\_link**. The parameter **--type** was removed from **\_\_file**. Thus you
need to replace **\_\_file** calls in your manifests:

 * Remove --type from all \_\_file calls
 * If type was symlink, use \_\_link and --type symbolic
 * If type was directory, use \_\_directory


## Support

### IRC

You can join the development ***IRC channel***
[#cstar on irc.freenode.net](irc://irc.freenode.org/#cstar).

### Mailing list

Bug reports, questions, patches, etc. should be send to the
[cdist mailing list](http://l.schottelius.org/mailman/listinfo/cdist).

### Linkedin

If you have an account
at [Linked in](http://www.linkedin.com/),
you can join the
[cdist group](http://www.linkedin.com/groups/cdist-configuration-management-3952797).

### Commercial support

You can request commercial support for cdist from
[my company](http://firma.schottelius.org/english/).

## Used by

If you're using cdist, feel free to send a report to the mailing list.
Interesting information are for instance

 * Which services do you manage?
 * How many machines do you manage?
 * What are the pros/cons you see in cdist?
 * General comments/critics

### Nico Schottelius, Systems Group ETH Zurich, local.ch and privately

Yes, I'm actually eating my own dogfood and currently managing

 * [plone](http://plone.org/) (cms)
 * [moinmoin](http://moinmo.in/) (wiki)
 * [apache](http://httpd.apache.org/) (webserver)
 * [kerberos (mit)](http://web.mit.edu/kerberos/) (authentication)
 * [nss-pam-ldapd](http://arthurdejong.org/nss-pam-ldapd/) (authentication)
 * [ircd-hybrid](http://www.ircd-hybrid.org/) (chat)
 * [stunnel](http://stunnel.mirt.net/) (SSL tunnel)
 * [mercurial-server](http://www.lshift.net/mercurial-server.html) (version control)
 * [xfce](http://www.xfce.org/) (lightweight desktop environment)
 * [slim](http://slim.berlios.de/) (graphical login manager for X11)

with cdist on more than **60** production machines of the
[Systems Group](http://www.systems.ethz.ch) at the
[ETH Zurich](http://www.ethz.ch) as well at home.

### Steven Armstrong, CBRG ETH Zurich

The CBRG is managing most of their compute clusters with cdist.

[[!tag cdist unix]]