Opening and reading files may cause your program to block indefinitely. In this blogpost we'll discuss how to work around this issue.
This guide is designed for the novice user of CFEngine who wishes to explore the power of Emacs while developing CFEngine policy files – and will introduce the use of some Emacs features and plugins along the way. There are two types of editors available in the Unix and Linux world: line and visual. Examples of line editors are ed and sed. These allow you to edit a file one line at a time.
As a person who tries to work with as few resources as possible, whether it’s editing everything with ed(1) or using old laptops without screens for servers or turning off computers as much as possible I am happy to announce nightly packages are available for the aarch64 (ARM 64-bit) architecture. This enables low-power, low-cost devices such as the Raspberry Pi and many others to run CFEngine Enterprise. Why run CFEngine? It is lean on resources and rich in features!
What’s autorun? Autorun is a feature of the Masterfiles Policy Framework (MPF)1 that simplifies the process of adding and executing new policy. We have talked about Modular policies with autorun and the Augments before. This time, we dig into autorun a bit deeper to explore some of its current features and look at how to implement your own as we did during The Agent is In, Episode 15 - Extending Autorun
This is the second blog post in a short series about processes on UNIX-like systems. It is a followup to the previous post which focused on basic definitions, creation of processes and relations between them. This time we analyze the semantics of two closely related system calls that play major roles in process creation and program execution. fork() and exec() The UNIX-based operating systems provide the fork() system call1 to create a clone of an existing process and the execve() system call to start executing a program in a process.
While working on the integration of CFEngine Build into Mission Portal we came to the point where we needed to start executing separate tools from our recently added daemon - cf-reactor. Although it may seem like nothing special, knowing a bit about the process creation and program execution specifics (and having to fight some really hard to solve bugs in the past) we spent a lot of time and effort on this step.
Databases are great for data processing and storage. However, in many cases it is better or easier to work with data in files on a file system, some tools even cannot access the data in any other way. When a database (DB) is created in a database management system (DBMS) using a file system as its data storage, it of course uses files on the given file system to store the data.
In this blog post we show how it is possible to run an arbitrary program, script, or execute arbitrary code in reaction to changes and generally events in a PostgreSQL database. Triggers Database management systems (DBMS) provide mechanisms for defining reactions to certain actions or, in other words, for defining that specific actions should trigger specific reactions. PostgreSQL, the DBMS used by CFEngine Enterprise, is no exception. These triggers can be used for ensuring consistency between tables when changes in one table should be reflected in another table, for recording information about actions, and many other things.
Interested in the efforts underway to make CFEngine manage the environment even faster? Vratislav (Software Engineer) joins the show to talk about cf-reactor 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. Join the next webinar to not miss this discussion. Links cf-reactor cf-runagent sockets Connect on LinkedIn w/ Cody, Craig, Herman, Nick, or Vratislav All Episodes
CFEngine and Ansible are two complementary infrastructure management tools. Findings from our analysis show that they can be combined and used side by side with joint forces to handle all areas in the best possible way. Part of infrastructure management is hosts deployment, either when building a brand new infrastructure or when growing one by adding new hosts. This is something Ansible truly excels in as it makes it very easy to run a sequence of steps on all hosts to initialize (deploy) them and it only requires SSH access to the hosts and Python installed on them.
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