2016-11-27 15:32:05 +00:00
<!DOCTYPE html>
<!-- [if IE 8]><html class="no - js lt - ie9" lang="en" > <![endif] -->
<!-- [if gt IE 8]><! --> < html class = "no-js" lang = "en" > <!-- <![endif] -->
< head >
< meta charset = "utf-8" >
< meta name = "viewport" content = "width=device-width, initial-scale=1.0" >
2016-12-03 09:18:03 +00:00
< title > 15. Messaging — cdist 4.4.0-182-g70369bf documentation< / title >
2016-11-27 15:32:05 +00:00
< link rel = "stylesheet" href = "_static/css/theme.css" type = "text/css" / >
< link rel = "index" title = "Index"
href="genindex.html"/>
< link rel = "search" title = "Search" href = "search.html" / >
2016-12-03 09:18:03 +00:00
< link rel = "top" title = "cdist 4.4.0-182-g70369bf documentation" href = "index.html" / >
2016-11-27 15:32:05 +00:00
< link rel = "next" title = "16. Parallelization" href = "cdist-parallelization.html" / >
< link rel = "prev" title = "14. Explorer" href = "cdist-explorer.html" / >
< script src = "_static/js/modernizr.min.js" > < / script >
< / head >
< body class = "wy-body-for-nav" role = "document" >
< div class = "wy-grid-for-nav" >
< nav data-toggle = "wy-nav-shift" class = "wy-nav-side" >
< div class = "wy-side-scroll" >
< div class = "wy-side-nav-search" >
< a href = "index.html" class = "icon icon-home" > cdist
< / a >
< div class = "version" >
2016-12-03 09:18:03 +00:00
4.4.0-182-g70369bf
2016-11-27 15:32:05 +00:00
< / div >
< div role = "search" >
< form id = "rtd-search-form" class = "wy-form" action = "search.html" method = "get" >
< input type = "text" name = "q" placeholder = "Search docs" / >
< input type = "hidden" name = "check_keywords" value = "yes" / >
< input type = "hidden" name = "area" value = "default" / >
< / form >
< / div >
< / div >
< div class = "wy-menu wy-menu-vertical" data-spy = "affix" role = "navigation" aria-label = "main navigation" >
< ul class = "current" >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-intro.html" > 1. cdist - usable configuration management< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-why.html" > 2. Why should I use cdist?< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-os.html" > 3. Supported Operating Systems< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-install.html" > 4. How to install cdist< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-update.html" > 5. How to update cdist< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-support.html" > 6. Support< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-features.html" > 7. Features< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-quickstart.html" > 8. Quickstart< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "man1/cdist.html" > 9. cdist(1)< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-bootstrap.html" > 10. Bootstrap< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-manifest.html" > 11. Manifest< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-type.html" > 12. cdist type< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-types.html" > 13. cdist types< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-explorer.html" > 14. Explorer< / a > < / li >
< li class = "toctree-l1 current" > < a class = "current reference internal" href = "#" > 15. Messaging< / a > < ul >
< li class = "toctree-l2" > < a class = "reference internal" href = "#description" > 15.1. Description< / a > < / li >
< li class = "toctree-l2" > < a class = "reference internal" href = "#availability" > 15.2. Availability< / a > < / li >
< li class = "toctree-l2" > < a class = "reference internal" href = "#examples" > 15.3. Examples< / a > < / li >
< / ul >
< / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-parallelization.html" > 16. Parallelization< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-inventory.html" > 17. Inventory< / a > < / li >
2016-11-27 17:43:52 +00:00
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-trigger.html" > 18. Trigger< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-preos.html" > 19. PreOS< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-reference.html" > 20. Reference< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-best-practice.html" > 21. Best practice< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-stages.html" > 22. Execution stages< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-remote-exec-copy.html" > 23. Remote exec and copy commands< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-hacker.html" > 24. Hacking< / a > < / li >
< li class = "toctree-l1" > < a class = "reference internal" href = "cdist-troubleshooting.html" > 25. Troubleshooting< / a > < / li >
2016-11-27 15:32:05 +00:00
< / ul >
< / div >
< / div >
< / nav >
< section data-toggle = "wy-nav-shift" class = "wy-nav-content-wrap" >
< nav class = "wy-nav-top" role = "navigation" aria-label = "top navigation" >
< i data-toggle = "wy-nav-top" class = "fa fa-bars" > < / i >
< a href = "index.html" > cdist< / a >
< / nav >
< div class = "wy-nav-content" >
< div class = "rst-content" >
< div role = "navigation" aria-label = "breadcrumbs navigation" >
< ul class = "wy-breadcrumbs" >
< li > < a href = "index.html" > Docs< / a > » < / li >
< li > 15. Messaging< / li >
< li class = "wy-breadcrumbs-aside" >
< a href = "_sources/cdist-messaging.txt" rel = "nofollow" > View page source< / a >
< / li >
< / ul >
< hr / >
< / div >
< div role = "main" class = "document" itemscope = "itemscope" itemtype = "http://schema.org/Article" >
< div itemprop = "articleBody" >
< div class = "section" id = "messaging" >
< h1 > 15. Messaging< a class = "headerlink" href = "#messaging" title = "Permalink to this headline" > ¶< / a > < / h1 >
< div class = "section" id = "description" >
< h2 > 15.1. Description< a class = "headerlink" href = "#description" title = "Permalink to this headline" > ¶< / a > < / h2 >
< p > cdist has a simple but powerful way of allowing communication between
the initial manifest and types as well as types and types.< / p >
< p > Whenever execution is passed from cdist to one of the
scripts described below, cdist generate 2 new temporary files
and exports the environment variables < strong > __messages_in< / strong > and
< strong > __messages_out< / strong > to point to them.< / p >
< p > Before handing over the control, the content of the global message
file is copied into the file referenced by < strong > $__messages_in< / strong > .< / p >
< p > After cdist gained control back, the content of the file referenced
by < strong > $__messages_out< / strong > is appended to the global message file.< / p >
< p > This way overwriting any of the two files by accident does not
interfere with other types.< / p >
< p > The order of execution is not defined unless you create dependencies
between the different objects (see < a class = "reference external" href = "cdist-manifest.html" > cdist manifest< / a > ) and thus you
can only react reliably on messages by objects that you depend on.< / p >
< / div >
< div class = "section" id = "availability" >
< h2 > 15.2. Availability< a class = "headerlink" href = "#availability" title = "Permalink to this headline" > ¶< / a > < / h2 >
< p > Messaging is possible between all < strong > local< / strong > scripts:< / p >
< ul class = "simple" >
< li > initial manifest< / li >
< li > type/manifest< / li >
< li > type/gencode-local< / li >
< li > type/gencode-remote< / li >
< / ul >
< / div >
< div class = "section" id = "examples" >
< h2 > 15.3. Examples< a class = "headerlink" href = "#examples" title = "Permalink to this headline" > ¶< / a > < / h2 >
< p > When you want to emit a message use:< / p >
< div class = "highlight-sh" > < div class = "highlight" > < pre > < span > < / span > < span class = "nb" > echo< / span > < span class = "s2" > " something" < / span > > > < span class = "s2" > " < / span > < span class = "nv" > $__messages_out< / span > < span class = "s2" > " < / span >
< / pre > < / div >
< / div >
< p > When you want to react on a message use:< / p >
< div class = "highlight-sh" > < div class = "highlight" > < pre > < span > < / span > < span class = "k" > if< / span > grep -q < span class = "s2" > " ^__your_type/object/id:something" < / span > < span class = "s2" > " < / span > < span class = "nv" > $__messages_in< / span > < span class = "s2" > " < / span > < span class = "p" > ;< / span > < span class = "k" > then< / span >
< span class = "nb" > echo< / span > < span class = "s2" > " I do something else" < / span >
< span class = "k" > fi< / span >
< / pre > < / div >
< / div >
< p > Some real life examples:< / p >
< div class = "highlight-sh" > < div class = "highlight" > < pre > < span > < / span > < span class = "c1" > # Reacting on changes from block for keepalive< / span >
< span class = "k" > if< / span > grep -q < span class = "s2" > " ^__block/keepalive-vrrp" < / span > < span class = "s2" > " < / span > < span class = "nv" > $__messages_in< / span > < span class = "s2" > " < / span > < span class = "p" > ;< / span > < span class = "k" > then< / span >
< span class = "nb" > echo< / span > /etc/init.d/keepalived restart
< span class = "k" > fi< / span >
< span class = "c1" > # Reacting on changes of configuration files< / span >
< span class = "k" > if< / span > grep -q < span class = "s2" > " ^__file/etc/one" < / span > < span class = "nv" > $__messages_in< / span > < span class = "p" > ;< / span > < span class = "k" > then< / span >
< span class = "nb" > echo< / span > < span class = "s1" > ' for init in /etc/init.d/opennebula*; do $init restart; done' < / span >
< span class = "k" > fi< / span >
< / pre > < / div >
< / div >
< p > Restart sshd on changes< / p >
< div class = "highlight-sh" > < div class = "highlight" > < pre > < span > < / span > < span class = "nv" > os< / span > < span class = "o" > =< / span > < span class = "s2" > " < / span > < span class = "k" > $(< / span > cat < span class = "s2" > " < / span > < span class = "nv" > $__global< / span > < span class = "s2" > /explorer/os" < / span > < span class = "k" > )< / span > < span class = "s2" > " < / span >
< span class = "k" > case< / span > < span class = "s2" > " < / span > < span class = "nv" > $os< / span > < span class = "s2" > " < / span > in
centos< span class = "p" > |< / span > redhat< span class = "p" > |< / span > suse< span class = "o" > )< / span >
< span class = "nv" > restart< / span > < span class = "o" > =< / span > < span class = "s2" > " /etc/init.d/sshd restart" < / span >
< span class = "p" > ;;< / span >
debian< span class = "p" > |< / span > ubuntu< span class = "o" > )< / span >
< span class = "nv" > restart< / span > < span class = "o" > =< / span > < span class = "s2" > " /etc/init.d/ssh restart" < / span >
< span class = "p" > ;;< / span >
*< span class = "o" > )< / span >
cat < span class = "s" > < < eof > & 2< / span >
< span class = "s" > Unsupported os $os.< / span >
< span class = "s" > If you would like to have this type running on $os,< / span >
< span class = "s" > you can either develop the changes and send a pull< / span >
< span class = "s" > request or ask for a quote at www.ungleich.ch< / span >
< span class = "s" > eof< / span >
< span class = "nb" > exit< / span > 1
< span class = "p" > ;;< / span >
< span class = "k" > esac< / span >
< span class = "k" > if< / span > grep -q < span class = "s2" > " ^__key_value/PermitRootLogin" < / span > < span class = "s2" > " < / span > < span class = "nv" > $__messages_in< / span > < span class = "s2" > " < / span > < span class = "p" > ;< / span > < span class = "k" > then< / span >
< span class = "nb" > echo< / span > < span class = "nv" > $restart< / span >
< span class = "k" > fi< / span >
< / pre > < / div >
< / div >
< / div >
< / div >
< / div >
< / div >
< footer >
< div class = "rst-footer-buttons" role = "navigation" aria-label = "footer navigation" >
< a href = "cdist-parallelization.html" class = "btn btn-neutral float-right" title = "16. Parallelization" accesskey = "n" > Next < span class = "fa fa-arrow-circle-right" > < / span > < / a >
< a href = "cdist-explorer.html" class = "btn btn-neutral" title = "14. Explorer" accesskey = "p" > < span class = "fa fa-arrow-circle-left" > < / span > Previous< / a >
< / div >
< hr / >
< div role = "contentinfo" >
< p >
© Copyright .
< / p >
< / div >
Built with < a href = "http://sphinx-doc.org/" > Sphinx< / a > using a < a href = "https://github.com/snide/sphinx_rtd_theme" > theme< / a > provided by < a href = "https://readthedocs.org" > Read the Docs< / a > .
< / footer >
< / div >
< / div >
< / section >
< / div >
< script type = "text/javascript" >
var DOCUMENTATION_OPTIONS = {
URL_ROOT:'./',
2016-12-03 09:18:03 +00:00
VERSION:'4.4.0-182-g70369bf',
2016-11-27 15:32:05 +00:00
COLLAPSE_INDEX:false,
FILE_SUFFIX:'.html',
HAS_SOURCE: true
};
< / script >
< script type = "text/javascript" src = "_static/jquery.js" > < / script >
< script type = "text/javascript" src = "_static/underscore.js" > < / script >
< script type = "text/javascript" src = "_static/doctools.js" > < / script >
< script type = "text/javascript" src = "_static/js/theme.js" > < / script >
< script type = "text/javascript" >
jQuery(function () {
SphinxRtdTheme.StickyNav.enable();
});
< / script >
< / body >
< / html >
