72 lines
2 KiB
Text
72 lines
2 KiB
Text
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cdist-messaging(7)
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==================
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Nico Schottelius <nico-cdist--@--schottelius.org>
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NAME
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----
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cdist-messaging - How the initial manifest and types can communication
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DESCRIPTION
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-----------
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cdist has a simple but powerful way of allowing communication between
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the initial manifest and types as well as types and types.
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Whenever execution is passed from cdist to one of the
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scripts described below, cdist generate 2 new temporary files
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and exports the environment variables __messages_in and
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__messages_out to point to them.
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Before handing over the control, the content of the global message
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file is copied into the file referenced by $__messages_in.
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After cdist gained control back, the content of the file referenced
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by $__messages_out is appended to the global message file.
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This way overwriting any of the two files by accident does not
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interfere with other types.
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The order of execution is not defined unless you create dependencies
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between the different objects (see cdist-manifest(7)) and thus you
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can only react reliably on messages by objects that you depend on.
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AVAILABILITY
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------------
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Messaging is possible between all **local** scripts:
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- initial manifest
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- type/manifest
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- type/gencode-local
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- type/gencode-remote
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EXAMPLES
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--------
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When you want to emit a message use:
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--------------------------------------------------------------------------------
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echo "something" >> "$__messages_out"
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--------------------------------------------------------------------------------
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When you want to react on a message use:
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--------------------------------------------------------------------------------
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if grep -q "^__your_type/object/id:something" "$__messages_in"; then
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echo "I do something else"
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fi
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--------------------------------------------------------------------------------
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SEE ALSO
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--------
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- cdist(1)
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- cdist-manifest(7)
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- cdist-reference(7)
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- cdist-type(7)
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COPYING
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-------
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Copyright \(C) 2013 Nico Schottelius. Free use of this software is
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granted under the terms of the GNU General Public License version 3 (GPLv3).
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