Did you know you can find classes by name and tag? classesmatching() dynamically sources information from the current state. For example, let’s say you have classes representing a system’s role. Furthermore, let’s say that we want a host to only have a single role class defined. …
Whether you are migrating from Ansible to CFEngine to gain some of the benefits of scale or autonomy or just need some functionality in an Ansible module, the ansible promise type can be a great tool to utilize. It also provides a compelling alternative to ansible-pull and works around some of the …
Are you familiar with CFEngine’s special variables? Probably you are familiar with sys variables like sys.fqhost (the fully qualified host name) and sys.policy_hub (the IP address of the machine the host is bootstrapped to) but I want to highlight a few other special variables you may not be …
Did you know that CFEngine has namespaces? Let’s see how they can facilitate policy sharing while avoiding “duplicate definitions of bundle” errors. Most of the Masterfiles Policy Framework (MPF) and policy examples for CFEngine use the default namespace. However, body file control …
Did you know you can include one policy file from another? Traditionally you specify the files you want to make up a policy set using inputs in body common control found in your policy entry (promises.cf by default). body common control { # Paths are relative to $(sys.policy_entry_dirname) if not # …
Ever want to run just a one or a few select bundles from your policy? While developing policy it’s common to run cf-agent -KI so that you can quickly iterate on changes and then run the policy without locks. But if you are focused on select bundles you may not need the full policy to run, you …
Ever wanted to make sure a promise only runs if some other promise has succeeded? Consider this contrived example with two reports type promises, It's Friday! and I love CFEngine Feature Friday. Per normal ordering1, these two promises will be emitted in the written order. /tmp/feature-friday-7.cf …
Will your policy work? cf-promises can check the CFEngine policy for syntax errors and give you an overview of the host’s context. It’s always a good idea to check your policy for syntax errors. Consider this policy file: /tmp/feature-friday-6.cf bundle agent feature_friday { reports: …
When you want to inspect both the return code and output from a command execresult_as_data() might be the function you are searching for. Most CFEngine policy writers have used execresult() and returnszero(). They are useful when you want to do something based on the output of a command or based on …
Have you ever wanted some hosts to organize themselves into different groups, but without spending time to worry about assigning a specific group? Cody, Craig, and Nick talk about using the select_class feature in CFEngine. Nick implements automatic assignment of a maintainer for each host: You want …
Sign up for CFEngine Enterprise and connect up to 25 hosts for free. No credit card required. Get started in minutes.
Try enterprise for free
