GitLab provides more than what Jenkins is hoping to evolve to, by providing a fully integrated single application for the entire DevOps lifecycle. More than Jenkins’ goals, GitLab also provides planning, SCM, packaging, release, configuration, and monitoring (in addition to the CI/CD that Jenkins is focused on). With Gitlab, there is no need for plugins and customization. Unlike Jenkins, GitLab is open core and anyone can contribute changes directly to the codebase, which once merged would be automatically tested and maintained with every change.
Maintaining GitLab is quite easy to maintain and update. To upgrade, just replace one docker image
When you upgrade version, it upgrades everything.
Maintaining Pipleline Definitions are cleaner and easier than in Jenkins. The GitLab CI/CD configuration file (.gitlab-ci.yml):
Uses a structured YAML format
Has a shorter learning curve - simpler to get up and running
Prevents unconstrained complexity - which can make your Jenkins pipeline files hard to understand and manage
Versioned in repository next to your code - makes it easy to maintain and update by developers
Optimized for Cloud Native development
Built-in container registry
Microservices CI/CD logic
Visiblity and Intuitiveness
Developers have visibility to the entire development lifecycle
Modern UX and ease of use
Better execution architecture
The GitLab Runner, which executes your CI/CD jobs, has an execution architecture that is more adaptable than Jenkins
Written in Go for portability - distributed as single binary without any other requirements.
Native Docker support - Jobs run in Docker containers. GitLab Runner downloads the container images with the necessary tools, runs the jobs, then removes the container.
No extra dev tool pre-installs needed on the Runner machines
Built-in auto-scaling - machines created on demand to match job demand. Enables cost savings by using resources more dynamically.
GitLab has a Single Permission Model which makes setting roles and permissions in GitLab faser and easier.