Technology stack, also called a solution stack, is a set of software components that compose a logically complete platform for running a service or supporting an application.
DevOps – a culture of improving quality and pace of software development by bringing Development and Operations teams closer: better communication, smaller and more frequent software changes, continuous (automated) deployment and integration plus greatly increased visibility (monitoring) are among key benefits.
Operating system, all sorts of server software, small local services running on the OS along with any automation solutions – all of these can be part of a technology stack.
Backporting is a software maintenance approach where specific functionality from a current software release is extracted and applied to an older release of the same software.
Most commonly, backporting is used for making most recent security fixes to multiple older releases of a particularly popular software package used in older operating systems. For instance, OpenSSH or OpenSSL packages are updated with back ported security fixes to allow you address recent vulnerabilities by upgrading just the affected package instead of upgrading all of the older operating system.
EOL is the date indicating the end of commercial support for a particular OS or software version. Most vendors have 3-5 years or even longer period of support available for each product, so you usually have plenty of time to upgrade your environment to a more recent software version.
In case of an operating system, EOL indicates when you will stop receiving any software updates. EOL doesn’t mean there are updates but your product won’t be able to receive them: it actually means there will be no further updates made by the vendor.
git is a distributed version control system – a software that allows multiple teams and software developers to collaboratively develop and maintain a software project with minimal friction. This means each developer can work on their own version of the code that’s not blocking any other development or testing cycle, with changes integrated into main code branch in a fully controlled (and easily reversible) way.
GitOps is an operational mode where all of the software defined infrastructure for a project is configured, developed and maintained using source control system (usually git). Each infrastructure state is versioned, meaning all the changes can be reverted or reapplied by manipulating code.
GitOps uses push or pull based deployment mechanism – but in both cases promoting a new version of code into a Git repository results in the refresh, reconfiguration and even restart (if necessary) of all the relevant infrastructure and software elements.
Instead of manually starting and configuring physical or virtual servers, GitOps works with clusters like Kubernetes and software defined elements like auto-scaling groups, load balancers, security groups and dynamically allocated/attached storage.