GitLab - an introduction

 

GitLab is a code hosting and issue tracking web platform based around the Git version control system. First released in 2011, it has continued to grow and evolve over the years, adding new features and capabilities, and has turned into a one-stop tool for an agile workforce. While it is owned and managed by GitLab Inc., who steer the direction of the project, the core of GitLab is open source software with over 2,000 separate contributors to date

Version control systems and Git Let's say you write code, or work on a book, or even just want to collect and update a set of text-based documents. You need some method of keeping track of changes, of being able to revert mistakes in the work, or branch in new directions; and you'll probably want some way of remotely backing up your work in case of fire, theft, or acts of a misbehaving computer. This is where version control systems (also known as VCS) come in handy. They save your work at certain points (commits) and can be reverted to earlier states; many VCS offer methods of branching so that you can – for example – work on a specific feature without interrupting someone else's work on another component. There are many version control systems on the market, but the most prominent in the public eye would be Git. Git is a distributed version control system, which means that it has a full copy of all of the code that exists on each user's computer, and users can pass patches and changes directly between each other rather than entirely relying on a centralized server.

 

Behind the scenes, git is an advanced program that is lightning fast when it comes to performing operations like staging work, committing changes, or swapping between branches. It's efficient at fetching information from remote repositories to help speed up a user's workflow. Unlike most VCS, git doesn't work by storing the changes that happen to each file. Instead, on every commit, git stores a snapshot of the current state of all files. If a file hasn't changed, rather than storing it again, it simply stores a reference to the last saved version of the file. When you make a commit, git captures the snapshot and also takes a cryptographic hash – a series of complex mathematical operations on the data that produces a unique value – and uses the output of that as a reference to the commit, along with some metadata, such as the author. This snapshot sits on top of the rest of the snapshots/commits that you've taken, and in this way you can think of git snapshots as a series of changesets – operations that add or remove lines – that can be performed on your files to get them to an older or newer state.

 

GitLab and Git

GitLab is built on top of git so that users who are contributing work (editing code, writing chapters, and so on) to a project will have a copy of the project downloaded/checked out/cloned on their local computer. It provides a web interface for handling many of git's more advanced workflows, and recommends a workflow for interacting with git for the best in productivity, efficiency, and ease of use.

By acting as a single source of truth for your developers, GitLab can help you avoid conflicts and the double handling of work while maintaining uptime by relying on the battle-tested GitLab.com platform or your own installation of it, working with tools including geographic replication, disaster recovery, and automated failover.

 

Features

GitLab provides a number of ways to view and interact with a git repository

There's also a branch viewer, which lets you see variations of your work under active development. Alongside this is a tag viewer that lets you explore specific releases of your work.

There are tools that can be used to analyze and view the commit graph.

Among these tools are charting tools, which are used to get a better understanding of the composition of the repository.

 

Self-managed versus Software as a Service (SaaS)

 GitLab can be used in one of two ways: either self-managed, where you host your own instance of GitLab Community Edition/Enterprise Edition, or using the online platform GitLab.com, which comes as a paid or free Software as a Service (SaaS) model.

 

Using GitLab.com comes with the benefits of no maintenance or infrastructure costs and regular automatic updates without any manual labour. They have an amazing setup with multiple backup strategies, redundancies, and failovers to ensure high uptime and no loss of data in the event of a major incident. On the other hand, you might not feel comfortable putting all of your work on someone else's infrastructure, which is why GitLab provides an easy-to-install omnibus package that can be installed on your own computer or a server that you host. This can also be handy if you have strict security and firewall requirements that don't allow for externally hosted code. There's also the benefit of easy integration with your own LDAP or Active Directory services for user management, and potential performance gains in larger repositories from not having to shift large amounts of data over external network links.

Free versus paid Lastly, there are multiple tiers of GitLab for both the self-managed and SaaS versions. Please note that both versions can be used for free and provide all of the main features that you'd expect (git hosting, code review, issue management, testing, and deployment). The added tiers provide extra features that are available at different levels of pricing on a peruser, per-month basis. For example, at the lowest paid tier, you get priority and nextbusiness-day support, and with the SaaS version, you also get burndown charts, multiple approval requirements on merge requests, and issue weighting. At the higher levels, more features get added, including the following:

 

Service desk mode

Canary deployments

Support for multiple Kubernetes clusters

 CI/CD for external repositories

Disaster recovery

 Epics

Roadmaps, and much more

 

 

Operating system

GitLab provides an omnibus package for installation on a number of platforms. This package has everything required to run a full-fledged GitLab instance, including the database (PostgreSQL), in-memory caching platform (Redis), background task queue (Sidekiq), and monitoring platform (Prometheus). This is the recommended way of installing GitLab for most circumstances, unless you are setting up for a massive instance, want more fine-grained control over the components, are looking to run your own public code hosting platform, use an unsupported Unix-based OS, or are reusing other equipment and servers. The omnibus package is currently available for the following operating systems

Ubuntu

Debian

CentOS

OpenSUSE

Red Hat Enterprise Linux (RHEL)

 Scientific Linux

Oracle Linux

If your operating system flavor of choice hasn't been mentioned, there is still the option of a manual installation, which has been tested on distributions including the following:

 Arch Linux

Fedora

FreeBSD

Gentoo

mac OS