What types of GitLab Runners are there?

In GitLab Runner, there are the following main types:

1. Shared Runners — available for all projects in GitLab and usually managed by GitLab administrators. Used for executing tasks from different projects.

2. Specific Runners — tied to a particular project or group of projects. Used when isolated or specialized environments are required.

3. Group Runners — assigned to a group of projects, accessible to all projects within that group.

Additionally, based on the method of task execution, they are distinguished as:

• Shell Runner — executes tasks in the operating system shell.
• Docker Runner — runs tasks inside Docker containers.
• Docker Machine Runner — automatically creates and deletes Docker hosts.
• Kubernetes Runner — runs tasks in a Kubernetes cluster.

The choice of Runner type depends on requirements for isolation, scalability, and infrastructure.