Show posts tagged:
custom-promise-types

Introducing bodies with custom promise types

Last year we had a look at managing local groups with the custom groups promise type. As you may or may not recall, we used JSON-strings to imitate CFEngine bodies. This was due to the fact that the promise module protocol did not support bodies at that time. Today, on the other hand, we’re happy to announce that as of CFEngine 3.20, this will no longer be the case. In this blog post we’ll introduce the long awaited feature; custom bodies.

Posted by Lars Erik Wik
February 8, 2022

Announcing CFEngine Build

Earlier this year, we hinted at what we were working on - a place for users to find and share reusable modules for CFEngine. Today, the CFEngine team is pleased to announce the launch of CFEngine Build: The new website, build.cfengine.com, allows you to browse for modules, and gives you information about how to use each one of them. When you’ve found the module you were looking for, it can be downloaded and built using the command line tooling.

November 1, 2021

Managing local groups

Manually managing groups on a large infrastructure can be a tedious task, and is therefore best suited through automation software like CFEngine. Unfortunately - at time of writing - CFEngine does not have any built-in promise types for managing groups. But fear not; in CFEngine 3.17, custom promise types were introduced. This new exhilarating feature does not only allow for members of our community to make their own custom promise types, but also lets the CFEngine Core developers prototype new future promise types.

Posted by Lars Erik Wik
October 1, 2021

Cloning git repos and creating systemd services with CFEngine

Using modules, you can add custom promise types to CFEngine, to manage new resources. In this blog post, I’d like to introduce some of the first official modules, namely git and systemd promise types. They were both written by Fabio Tranchitella, who normally works on our other product, Mender.io. He decided to learn some CFEngine and within a couple of weeks he’s contributed 3 modules, showing just how easy it is to implement new promise types.

August 16, 2021

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. To implement a custom promise type in CFEngine, you need a promise module. The module is an executable, and can be written in any language. It’s possible to write one from scratch, but to make it as easy as possible, we decided to provide libraries for common programming languages.

January 29, 2021

Custom Promise outcomes in Mission Portal

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. Creating a promise type for whether a site is up We will use Python and the CFEngine library to implement a promise module.

January 21, 2021

How to implement CFEngine Custom Promise Types in Python

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. Why Python? Promise modules can be written in any programming language, but there are some advantages of using python: Readable and beginner friendly language / syntax Popular and familiar to a lot of people, also used in some CFEngine package modules Big standard library, allowing you to reuse data structures, parsers, etc.

December 8, 2020

Introducing CFEngine Custom Promise Types

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. (The promise type is what you use in policy language (the concept), while the module is the underlying implementation - can be a python script, compiled executable or similar).

December 3, 2020
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