diff --git a/docs/man/man7/cdist-messaging.text b/docs/man/man7/cdist-messaging.text new file mode 100644 index 00000000..0e53871e --- /dev/null +++ b/docs/man/man7/cdist-messaging.text @@ -0,0 +1,72 @@ +cdist-messaging(7) +================== +Nico Schottelius + +NAME +---- +cdist-messaging - How the initial manifest and types can communication + + +DESCRIPTION +----------- +cdist has a simple but powerful way of allowing communication between +the initial manifest and types as well as types and types. + +Whenever execution is passed from cdist to one of the +scripts described below, cdist generate 2 new temporary files +and exports the environment variables __messages_in and +__messages_out to point to them. + +Before handing over the control, the content of the global message +file is copied into the file referenced by $__messages_in. + +After cdist gained control back, the content of the file referenced +by $__messages_out is appended to the global message file. + +This way overwriting any of the two files by accident does not +interfere with other types. + +The order of execution is not defined unless you create dependencies +between the different objects (see cdist-manifest(7)) and thus you +can only react reliably on messages by objects that you depend on. + + +AVAILABILITY +------------ +Messaging is possible between all **local** scripts: + +- initial manifest +- type/manifest +- type/gencode-local +- type/gencode-remote + + +EXAMPLES +-------- +When you want to emit a message use: + +-------------------------------------------------------------------------------- +echo "something" >> "$__messages_out" +-------------------------------------------------------------------------------- + +When you want to react on a message use: + +-------------------------------------------------------------------------------- +if grep -q "^__your_type/object/id:something" "$__messages_in"; then + echo "I do something else" +fi +-------------------------------------------------------------------------------- + + +SEE ALSO +-------- +- cdist(1) +- cdist-manifest(7) +- cdist-reference(7) +- cdist-type(7) + + +COPYING +------- +Copyright \(C) 2013 Nico Schottelius. Free use of this software is +granted under the terms of the GNU General Public License version 3 (GPLv3).