example_aborting_execution.markdown

layout	title	published	reviewed	reviewed-by
default	Aborting execution	true	2013-05-30	atsaloli

Sometimes it is useful to abort a bundle execution if certain conditions are not met, for example when validating input to a bundle. The following policy uses a list of regular expressions for classes, or class expressions that [cf-agent][cf-agent] will watch out for. If any of these classes becomes defined, it will cause the current bundle to be aborted.

[%CFEngine_include_example(abort.cf)%]

This is how the policy runs when the userlist is valid:

cf-agent -f unit_abort.cf

R: User name mark is valid at 4 letters
R: User name john is valid at 4 letters

This is how the policy runs when the userlist contains an invalid entry:

cf-agent -f unit_abort.cf

Bundle example aborted on defined class "invalid"

To run this example file as part of your main policy you need to make an additional change:

There cannot be two body agent control in the main policy. Delete the body agent control section from /var/cfengine/masterfiles/unit_abort.cf. Copy and paste abortbundleclasses => { "invalid" }; into /var/cfengine/masterfiles/controls/cf_agent.cf. If you add it to the end of the file it should look something like this:

...
    #  dryrun => "true";

    abortbundleclasses => { "invalid" };
}