How to implement CFEngine custom promise types in bash
This blog post will focus on the bash programming part of implementing a promise type. To understand what custom promise types are, and how to use them, you should read the introduction first.
This blog post will focus on the bash programming part of implementing a promise type. To understand what custom promise types are, and how to use them, you should read the introduction first.
CFEngine 3.17.0 introduced custom promise types, which enable CFEngine users to extend core functionality and policy language in a simple way. As an example of the power and simplicity of this new feature, I will show a promise type that helps to observe a website’s status. The module which implements this promise type was written in a couple of hours.
Several months ago I started the practice of using CFEngine Enterprise and its Mission Portal UI on a daily basis to manage the connected devices in my home. To start, I brought up an old desktop machine, cfengine-hub, to use as my hub and downloaded Enterprise, which is free for use up to 25 hosts. The next step in using best practices is to deploy policy from a version control repository.
2020 is nearly over, and we’d like to take a couple of minutes to reflect on our year as well as provide a sneak peek into what you can expect from us in 2021. Although it has been a year full of distractions, the CFEngine team has continued to make significant strides when it comes to product improvements and new features that help our users.
This tutorial focuses on how to write a promise module, implementing a new CFEngine promise type. It assumes you already know how to install promise modules and use custom promise types, as shown in the previous blog post.
In CFEngine 3.17, custom promise types were introduced. This allows you to extend policy language, managing resources which don’t have built in promise types. The implementation of custom promise types is open source, and available in both CFEngine Enterprise and CFEngine Community. To implement a new custom promise type, you need a promise module.
We are pleased to announce the release of CFEngine 3.17.0, with the theme Flexibility! This is a non-LTS release and allows the CFEngine community to test the features which will be in CFEngine 3.18.0 LTS (Summer 2021).