www.nico.schottelius.org/software/cdist/man/3.1.13/man7/cdist-manifest.html
2015-05-16 17:55:46 +02:00

140 lines
No EOL
14 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>cdist-manifest(7)</title><link rel="stylesheet" type="text/css" href="docbook-xsl.css" /><meta name="generator" content="DocBook XSL Stylesheets V1.78.1" /></head><body><div xml:lang="en" class="article" lang="en"><div class="titlepage"><div><div><h2 class="title"><a id="idm140610758624752"></a>cdist-manifest(7)</h2></div><div><div class="author"><h3 class="author"><span class="firstname">Nico</span> <span class="surname">Schottelius</span></h3><code class="email">&lt;<a class="email" href="mailto:nico-cdist--@--schottelius.org">nico-cdist--@--schottelius.org</a>&gt;</code></div></div></div><hr /></div><div class="toc"><p><strong>Table of Contents</strong></p><dl class="toc"><dt><span class="section"><a href="#_name">1. NAME</a></span></dt><dt><span class="section"><a href="#_description">2. DESCRIPTION</a></span></dt><dt><span class="section"><a href="#_initial_and_type_manifests">3. INITIAL AND TYPE MANIFESTS</a></span></dt><dt><span class="section"><a href="#_define_state_in_the_initial_manifest">4. DEFINE STATE IN THE INITIAL MANIFEST</a></span></dt><dt><span class="section"><a href="#_splitting_up_the_initial_manifest">5. SPLITTING UP THE INITIAL MANIFEST</a></span></dt><dt><span class="section"><a href="#_dependencies">6. DEPENDENCIES</a></span></dt><dt><span class="section"><a href="#_create_dependencies_from_execution_order">7. CREATE DEPENDENCIES FROM EXECUTION ORDER</a></span></dt><dt><span class="section"><a href="#_overrides">8. OVERRIDES</a></span></dt><dt><span class="section"><a href="#_examples">9. EXAMPLES</a></span></dt><dt><span class="section"><a href="#_see_also">10. SEE ALSO</a></span></dt><dt><span class="section"><a href="#_copying">11. COPYING</a></span></dt></dl></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_name"></a>1. NAME</h2></div></div></div><p>cdist-manifest - (Re-)Use types</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_description"></a>2. DESCRIPTION</h2></div></div></div><p>Manifests are used to define which objects to create.
Objects are instances of <span class="strong"><strong>types</strong></span>, like in object oriented programming languages.
An object is represented by the combination of
<span class="strong"><strong>type + slash + object name</strong></span>: <span class="strong"><strong>__file/etc/cdist-configured</strong></span> is an
object of the type <span class="strong"><strong><span class="strong"><strong>__file</strong></span></strong></span> with the name <span class="strong"><strong><span class="strong"><strong>etc/cdist-configured</strong></span></strong></span>.</p><p>All available types can be found in the <span class="strong"><strong>cdist/conf/type/</strong></span> directory,
use <span class="strong"><strong>ls cdist/conf/type</strong></span> to get the list of available types. If you have
setup the MANPATH correctly, you can use <span class="strong"><strong>man cdist-reference</strong></span> to access
the reference with pointers to the manpages.</p><p>Types in manifests are used like normal command line tools. Lets have a look
at an example:</p><pre class="screen"># Create object of type __package with the parameter state = absent
__package apache2 --state absent
# Same with the __directory type
__directory /tmp/cdist --state present</pre><p>These two lines create objects, which will later be used to realise the
configuration on the target host.</p><p>Manifests are executed locally as a shell script using <span class="strong"><strong>/bin/sh -e</strong></span>.
The resulting objects are stored in an internal database.</p><p>The same object can be redefined in multiple different manifests as long as
the parameters are exactly the same.</p><p>In general, manifests are used to define which types are used depending
on given conditions.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_initial_and_type_manifests"></a>3. INITIAL AND TYPE MANIFESTS</h2></div></div></div><p>Cdist knows about two types of manifests: The initial manifest and type
manifests. The initial manifest is used to define, which configurations
to apply to which hosts. The type manifests are used to create objects
from types. More about manifests in types can be found in <a href="../man7/cdist-type.html">cdist-type(7)</a>.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_define_state_in_the_initial_manifest"></a>4. DEFINE STATE IN THE INITIAL MANIFEST</h2></div></div></div><p>The <span class="strong"><strong>initial manifest</strong></span> is the entry point for cdist to find out, which
<span class="strong"><strong>objects</strong></span> to configure on the selected host.
Cdist expects the initial manifest at <span class="strong"><strong>cdist/conf/manifest/init</strong></span>.</p><p>Within this initial manifest you define, which objects should be
created on which host. To distinguish between hosts, you can use the
environment variable <span class="strong"><strong>__target_host</strong></span>. Lets have a look at a simple
example:</p><pre class="screen">__cdistmarker
case "$__target_host" in
localhost)
__directory /home/services/kvm-vm --parents yes
;;
esac</pre><p>This manifest says: Independent of the host, always use the type
<span class="strong"><strong><span class="strong"><strong>__cdistmarker</strong></span></strong></span>, which creates the file <span class="strong"><strong>/etc/cdist-configured</strong></span>,
with the timestamp as content.
The directory <span class="strong"><strong><span class="strong"><strong>/home/services/kvm-vm</strong></span></strong></span>, including all parent directories,
is only created on the host <span class="strong"><strong><span class="strong"><strong>localhost</strong></span></strong></span>.</p><p>As you can see, there is no magic involved, the manifest is simple shell code that
utilises cdist types. Every available type can be executed like a normal
command.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_splitting_up_the_initial_manifest"></a>5. SPLITTING UP THE INITIAL MANIFEST</h2></div></div></div><p>If you want to split up your initial manifest, you can create other shell
scripts in <span class="strong"><strong>cdist/conf/manifest/</strong></span> and include them in <span class="strong"><strong>cdist/conf/manifest/init</strong></span>.
Cdist provides the environment variable <span class="strong"><strong><span class="strong"><strong>__manifest</strong></span></strong></span> to reference
the directory containing the initial manifest (see <a href="../man7/cdist-reference.html">cdist-reference(7)</a>).</p><p>The following example would include every file with a <span class="strong"><strong>.sh</strong></span> suffix:</p><pre class="screen"># Include *.sh
for manifest in $__manifest/*.sh; do
# And source scripts into our shell environment
. "$manifest"
done</pre></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_dependencies"></a>6. DEPENDENCIES</h2></div></div></div><p>If you want to describe that something requires something else, just
setup the variable "require" to contain the requirements. Multiple
requirements can be added white space separated.</p><pre class="screen"> 1 # No dependency
2 __file /etc/cdist-configured
3
4 # Require above object
5 require="__file/etc/cdist-configured" __link /tmp/cdist-testfile \
6 --source /etc/cdist-configured --type symbolic
7
8 # Require two objects
9 require="__file/etc/cdist-configured __link/tmp/cdist-testfile" \
10 __file /tmp/cdist-another-testfile</pre><p>Above the "require" variable is only set for the command that is
immediately following it. Dependencies should always be declared that way.</p><p>On line 4 you can see that the instantion of a type "__link" object needs
the object "__file/etc/cdist-configured" to be present, before it can proceed.</p><p>This also means that the "__link" command must make sure, that either
"__file/etc/cdist-configured" allready is present, or, if its not, it needs
to be created. The task of cdist is to make sure, that the dependency will be
resolved appropriately and thus "__file/etc/cdist-configured" be created
if necessary before "__link" proceeds (or to abort execution with an error).</p><p>If you really need to make all types depend on a common dependency, you can
export the "require" variable as well. But then, if you need to add extra
dependencies to a specific type, you have to make sure that you append these
to the globally already defined one.</p><pre class="screen"># First of all, update the package index
__package_update_index
# Upgrade all the installed packages afterwards
require="__package_update_index" __package_upgrade_all
# Create a common dependency for all the next types so that they get to
# be executed only after the package upgrade has finished
export require="__package_upgrade_all"
# Ensure that lighttpd is installed after we have upgraded all the packages
__package lighttpd --state present
# Ensure that munin is installed after lighttpd is present and after all
# the packages are upgraded
require="$require __package/lighttpd" __package munin --state present</pre><p>All objects that are created in a type manifest are automatically required
from the type that is calling them. This is called "autorequirement" in
cdist jargon.</p><p>You can find an more in depth description of the flow execution of manifests
in <a href="../man7/cdist-stages.html">cdist-stages(7)</a> and of how types work in <a href="../man7/cdist-type.html">cdist-type(7)</a>.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_create_dependencies_from_execution_order"></a>7. CREATE DEPENDENCIES FROM EXECUTION ORDER</h2></div></div></div><p>You can tell cdist to execute all types in the order in which they are created
in the manifest by setting up the variable CDIST_ORDER_DEPENDENCY.
When cdist sees that this variable is setup, the current created object
automatically depends on the previously created object.</p><p>It essentially helps you to build up blocks of code that build upon each other
(like first creating the directory xyz than the file below the directory).</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_overrides"></a>8. OVERRIDES</h2></div></div></div><p>In some special cases, you would like to create an already defined object
with different parameters. In normal situations this leads to an error in cdist.
If you whish, you can setup the environment variable CDIST_OVERRIDE
(any value or even empty is ok) to tell cdist, that this object override is
wanted and should be accepted.
ATTENTION: Only use this feature if you are 100% sure in which order
cdist encounters the affected objects, otherwhise this results
in an undefined situation.</p><p>If CDIST_OVERRIDE and CDIST_ORDER_DEPENDENCY are set for an object,
CDIST_ORDER_DEPENDENCY will be ignored, because adding a dependency in case of
overrides would result in circular dependencies, which is an error.</p></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_examples"></a>9. EXAMPLES</h2></div></div></div><p>The initial manifest may for instance contain the following code:</p><pre class="screen"># Always create this file, so other sysadmins know cdist is used.
__file /etc/cdist-configured
case "$__target_host" in
my.server.name)
__directory /root/bin/
__file /etc/issue.net --source "$__manifest/issue.net
;;
esac</pre><p>The manifest of the type "nologin" may look like this:</p><pre class="screen">__file /etc/nologin --source "$__type/files/default.nologin"</pre><p>This example makes use of dependencies:</p><pre class="screen"># Ensure that lighttpd is installed
__package lighttpd --state present
# Ensure that munin makes use of lighttpd instead of the default webserver
# package as decided by the package manager
require="__package/lighttpd" __package munin --state present</pre><p>How to override objects:</p><pre class="screen"># for example in the inital manifest
# create user account foobar with some hash for password
__user foobar --password 'some_fancy_hash' --home /home/foobarexample
# ... many statements and includes in the manifest later ...
# somewhere in a conditionaly sourced manifest
# (e.g. for example only sourced if a special application is on the target host)
# this leads to an error ...
__user foobar --password 'some_other_hash'
# this tells cdist, that you know that this is an override and should be accepted
CDIST_OVERRIDE=yes __user foobar --password 'some_other_hash'
# it's only an override, means the parameter --home is not touched
# and stays at the original value of /home/foobarexample</pre><p>Dependencies defined by execution order work as following:</p><pre class="screen"># Tells cdist to execute all types in the order in which they are created ...
export CDIST_ORDER_DEPENDENCY=on
__sample_type 1
require="__some_type_somewhere/id" __sample_type 2
__example_type 23
# Now this types are executed in the creation order until the variable is unset
unset CDIST_ORDER_DEPENDENCY
# all now following types cdist makes the order ..
__not_in_order_type 42
# how it works :
# this lines above are translated to:
__sample_type 1
require="__some_type_somewhere/id __sample_type/1" __sample_type 2
require="__sample_type/2" __example_type 23
__not_in_order_type 42</pre></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_see_also"></a>10. SEE ALSO</h2></div></div></div><div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
<a href="../man7/cdist-tutorial.html">cdist-tutorial(7)</a>
</li><li class="listitem">
<a href="../man7/cdist-type.html">cdist-type(7)</a>
</li></ul></div></div><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="_copying"></a>11. COPYING</h2></div></div></div><p>Copyright (C) 2010-2014 Nico Schottelius. Free use of this software is
granted under the terms of the GNU General Public License version 3 (GPLv3).</p></div></div></body></html>