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. Our previous blog post, “How to implement CFEngine custom promise types in Python”, explains this in detail.
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. I use a local git server named git-server-zero instead of GitHub or GitLab as I like to be independent of the cloud when possible due to privacy and environmental concerns. I will use the Mission Portal Version Control Repository settings section to setup this repo as the source of policy for cfengine-hub.
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).
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).
What’s new? A new look - Mission Portal Dark Mode Mission portal now gives you the option of switching to an alternate color theme, dark mode:
Trigger report collection from Host Info Page You no longer have to wait for the next reporting interval, or use the command line to get updated reports. Click the button on the host info page to trigger a report collection:
My laptop was getting stale… I’ve been using it every work day for about 2.5 years now and so much software is installed it just boggles my mind. I really love it otherwise, open source, trying to be transparent, generally has worked amazingly! I have a Librem 15v3 from Purism. My home dir is a maze of old and new directories, odd files, tons of ~/Downloads junk. And the real kicker? I can’t build CFEngine core anymore! :( I tried to fix the situation but just couldn’t quite fix it. So the solution? Well reinstall PureOS of course and see if that helps things out.
Today we announce the newest additions to CFEngine. CFEngine 3.16 brings several improvements, bug fixes, and new features. The theme for this release has been compliance, and it notably includes a new category of reports for proving compliance to regulation and other compliance frameworks in high level, easy to read reports. If you are interested to learn more about CFEngine, schedule training, or hear about pricing options, feel free to reach out to us!
We are today very excited to bring you new updates to CFEngine. This is a set of patch releases for the CFEngine 3.12 LTS and 3.15 LTS series. We usually release new patch releases every 6 months, but we want to bring new features and all improvements and bug fixes to our users as soon as possible. Hence these early releases. In CFEngine 3.15 LTS we introduced Federated Reporting, our single pane of glass reporting architecture. This is a great new feature that allows you to set up a dedicated Hub that collects all reporting data from your entire infrastructure to really provide a single pane of glass into all your operations. In this patch release, we have included several performance improvements and bug fixes. There are no new features or larger changes in these patch releases. We focus on stability, improving performance, fixing bugs and are actively listening to open source users and customers alike when planning what to fix. We hope you enjoy the faster release this time and benefit from some of the improvements we have made.
CFEngine 2 network communication is insecure by today’s standards.
CFEngine 2 CVE-2016-6329: CFEngine 2 uses Blowfish cipher (1993) which today is considered: Weak Deprecated Subject to key recovery attack No security fixes since 2008. Protocol communications not encrypted; only data transfer (which facilitates attack). Encryption is off by default. CFEngine 3 All communication is encrypted Uses TLS 1.3 (current state of the art) Up to date, maintained, secure from the software vendor Full Enterprise support, with SLA. Solution CFEngine 3 was intentionally designed so that you can install it side by side with 2, so you have time to migrate your policies from 2 to 3.
Recently I wanted to start measuring the length of time it took for PostgreSQL to acquire a lock so that I could keep an eye on how it changes over time.
My PostgreSQL logs contain entries like the following that record the amount of time in ms it took to acquire a lock.
2019-06-11 18:49:39 GMT LOG: process 10427 acquired AccessShareLock on relation 17949 of database 16384 after 1118.396 ms at character 269 Measurement promises store and track values. Values can be sampled from either a pipe (command output) or a file as defined by the promises stream_type. Values are stored according to the promises history_type. When a measured value is not expected to change frequently a history_type of scalar or static will result in the measurement being sampled less frequently and the single value with compressed statistics will be stored. A history_type of log results in the measured value being logged as an infinite time-series in $(sys.statedir)/<PromiseHandle>_measure.log. A history_type of weekly results in the storing of a two-dimensional time average over a weekly period. Measurements with history_type of weekly are automatically graphed in Mission Portal if they are collected.
This was originally published here, it has been re-published with permission.
How can I execute a command that uses command substitution in CFEngine?
On the console I might execute something like this:
Listing 1: Example command substitution
touch /tmp/file-$(date --iso-8601) ls /tmp/file-* /tmp/file-2019-03-08 I recommend not executing commands using substitution. Instead, prepare all that you need up front. Get the result of the data command and put it into a CFEngine variable, then use the CFEngine variable directly.
