The latest updates about everything CFEngine

Feature Friday #19: What variables and classes are defined?

Do you know how to quickly see what variables and classes are defined? Often, while developing CFEngine policy it’s convenient to emit a variable value or a report based on the presence of a class. For example: bundle agent main { reports: "Unqualified hostname = '$(sys.uqhost)'"; linux:: "I am running on linux"; } In some cases, this is because you are exploring what classes are available. In other cases, it might be DEBUG-related reports helping you understand how a variable is resolved during policy evaluation.

Posted by Nick Anderson
July 19, 2024

Feature Friday #18: Augments - def.json

Ever want to get some data into CFEngine? Have you heard about the def.json Augments file?1 Augments are JSON data files that allow you to define classes and variables very early during agent initialization, before policy. Augments are practical in a variety of ways. Perhaps most notably for overriding policy defaults. Let’s look at a simple example. Here we have a policy /tmp/feature-friday/18-0.cf /tmp/feature-friday/18-0.cf bundle agent main { reports: "MyVariable $(with) defined '$(MyVariable)'" with => ifelse( isvariable( MyVariable ), "is", "is not" ); } Running it, we can see that MyVariable isn’t defined

Posted by Nick Anderson
July 12, 2024

Feature Friday #17: Tags for inventory and reporting

Let’s talk about tags and how they can be useful for Inventory and Reporting. If you have been following along with the Feature Friday series you already heard about using tags to find currently defined classes, variables and bundles, but they are also very useful for reporting. In CFEngine Enterprise the inventory and attribute_name tags are special. A variable or class tagged with inventory becomes visible in the Inventory subsystem in Mission Portal with the name given in the attribute_name tag.

Posted by Nick Anderson
July 5, 2024

Install and uninstall packages based on conditions

For security reasons, you generally want to uninstall talk, samba, and apache2 in your infrastructure. However, on your webservers, which have the webserver CFEngine class defined, you might want Apache to be installed. With the conditional-installer module, you can put talk,samba,apache2 in the list of packages to uninstall. And in the list of packages to install, you can put apache2 with the condition webserver. Hence, the module will install apache2 on your webservers and uninstall it everywhere else.

Posted by Craig Comstock
July 1, 2024

Feature Friday #16: host info report

Did you know the Masterfiles Policy Framework (MPF) ships with a host info report? That’s right, you can simply run cf-agent --bundlesequence host_info_report and a report will be generated. command cf-agent --bundlesequence host_info_report output R: Host info report generated and available at '/var/cfengine/reports/host_info_report.txt' It’s packed with information about the specific host. Let’s peek: command head -n 9 /var/cfengine/reports/host_info_report.txt output # Host Information Generated: Fri Feb 23 19:54:13 2024 ## Identity Fully Qualified Hostname: hub.

Posted by Nick Anderson
June 28, 2024

Show notes: The agent is in - Episode 38 - Sneak peek of CFEngine 3.24

Interested to see what’s new in the next LTS version (3.24) of CFEngine? Nick joins Craig and Cody to see what’s coming in 3.24. From the new groups feature which allows you to assign data to a group of hosts to improvements in filtering and new functionality in Build and other changes in behavior, checkout the video for all the details. Video The video recording is available on YouTube: At the end of every webinar, we stop the recording for a nice and relaxed, off-the-record chat with attendees.

Posted by Nick Anderson
June 27, 2024

Feature Friday #15: bundlesmatching()

Did you know bundles can have tags too? That’s right! You can tag a bundle by defining tags as a meta promise on a bundle. For example: bundle agent example_bundle_tag { meta: "tags" slist => { "tag_1", "tag_2" }; } You’ve likely encountered bundles tagged with autorun. These tags trigger automatic execution of bundles in lexical order whenever the services_autorun class is defined. However, you’re not limited to autorun. You can create custom tags to suite your specific needs.

Posted by Nick Anderson
June 21, 2024

CFEngine 3.18.8 and 3.21.5 released

We are pleased to announce two new patch releases for CFEngine, version 3.18.8 and 3.21.5! These patch releases contain bug fixes and dependency updates. Changes We’d like to highlight one specific change in behavior, which some users will want to adjust to; Change in behavior - depth_search can now be used (but warns) with an individual file as source Users of the depth_search attribute of file promises should be aware of this change in behavior.

June 20, 2024

Change in behavior: depth_search can now be used (but warns) with an individual file as source

You may see a new warning in the upcoming releases of 3.21.5 and 3.24.0. A new warning was introduced with a fix to the behavior of depth_search when combined with a copy_from source targeting a file: depth_search (recursion) is promised for a base object '<filename>' that is not a directory Prior to versions 3.21.5 and 3.24.0 CFEngine would copy the file initially but would subsequently avoid updating the file providing only debug log message about the fact that the file was being skipped (because it’s not possible to descend into a file).

Posted by Nick Anderson
June 19, 2024

Feature Friday #14: variablesmatching() & variablesmatching_as_data()

Did you know you can find variables by name and tag? Like the ability to find currently defined classes (as described in Feature Friday #13: classesmatching()) that match a name or tag, you can find variables by name and tag. It’s a nifty capability. variablesmatching() returns a list of variable names that match the name and tag criteria.1 variablesmatching_as_data() returns a data container of the matching variables along with their values2.

Posted by Nick Anderson
June 14, 2024