define stages

Signed-off-by: Nico Schottelius <nico@kr.ethz.ch>
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Nico Schottelius 2011-02-07 23:07:43 +01:00
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cdist-types(7) cdist-stages(7)
=============== ===============
Nico Schottelius <nico-cdist--@--schottelius.org> Nico Schottelius <nico-cdist--@--schottelius.org>
NAME NAME
---- ----
cdist-types - Functionality bundled cdist-stages - How the configuration is built
DESCRIPTION DESCRIPTION
----------- -----------
First stage: [done] Starting the execution of deployment with cdist-deploy-to(1),
- If cdist encounters type in manifest, cdist passes through different stages:
a wrapper script is run, that creates a
new entry in the cconfig database and adds
attribute values. This defines a cconfig
tree, that may look as follows:
<hostname>/<type>/<id>/<parameters>: - First stage: Get information about target
Every existing explorer (see cdist-explorers(7) is run on
the target and the results are copied back into the local
cache (see cdist-cache(7)). These values can be used by
manifests and types.
myhost/__file/cdist_bin/source - Second stage: Initial manifest run
myhost/__file/cdist_bin/destination The initial manifest (see cdist-manifests(7) is run,
... which is done by cdist-manifest-init(1).
- In this stage, no conflicts may occur, as This run creates an internal database in cconfig
no type code has been called (i.e. only format (see cdist-config-layout(7), that contains all
manifests, which map config to hosts is objects configured for the specific host.
applied).
Second stage: [done] In this stage, no conflicts may occur, i.e. no
- The "init" script of every used type object of the same type with the same id may
(i.e. the manifests created at least one object) be created.
is called, which again is able to call other
types. All created objects may also be modified
by the type.
For instance a "httpd" type may call the You can trigger the first stage part using
"webroot" type with --path / ... cdist-manifest-init(1).
# FIND CASE WHERE SENSEFUL => look through
current puppet config
- The newly created objects are merged back into - Third stage: Execution of types
Every object is checked whether its type has an init
script (see cdist-types(7)). If the type of the object
has an init script, it is run. This init script may
generate additional objects.
For instance the object __apache/www.test.ch is of
type __apache, which may contain an init script, which
creates new objects of type __file.
The newly created objects are merged back into
the existing tree. No conflicts may occur during the existing tree. No conflicts may occur during
the merge, because this would implicit that the the merge. A conflict would mean that two different
type conflicts with other types. objects try to create the same object, which indicates a
broken configuration.
The idea of this that a type may expand another - Third stage: Code generation
type with functionality, but may need to adjust The "gencode" binary of the types for every existing object is
("overwrite") settings from the original type. called to generate code that will be executed on the target host.
Third stage: This binary should create code to be executed on the target on stdout.
- Cdist calls the "gencode" binary of the types
for every created object. This binary should create
code to be executed on the target on stdout.
If the gencode binary fails, it must print diagnostic If the gencode binary fails, it must print diagnostic messages on stderr
messages on stderr and exit non-zero. and exit non-zero.
A description of what the generated code may/must/should A description of what the generated code may/must/should
do can be found at the end of this document. do can be found in cdist-types-gencode(7).
- Cdist merges together the generated code - Fourth stage:
(taking care of DEPENDENCIES (which are not The resulting code is transferred to the target host and executed,
yet defined (take care, double nested brackets))) the run of cdist-deploy-to(1) ends.
Fourth stage:
- The resulting shell script is transferred
to the target and executed.
SEE ALSO SEE ALSO
-------- --------
cdist(7), cdist-deploy-to(1), cdist-config-layout(7), cdist-manifest-init(1)
COPYING COPYING