.gitlab-ci-default-runners.yml

# From https://docs.gitlab.com/ee/user/gitlab_com/#shared-runners:
#
#   ...
#
#   All your CI/CD jobs run on n1-standard-1 instances with 3.75GB of RAM, CoreOS
#   and the latest Docker Engine installed. Instances provide 1 vCPU and 25GB of
#   HDD disk space. The default region of the VMs is US East1. Each instance is
#   used only for one job, this ensures any sensitive data left on the system can’t
#   be accessed by other people their CI jobs.
#
#   The gitlab-shared-runners-manager-X.gitlab.com fleet of runners are dedicated
#   for GitLab projects as well as community forks of them. They use a slightly
#   larger machine type (n1-standard-2) and have a bigger SSD disk size. They don’t
#   run untagged jobs and unlike the general fleet of shared runners, the instances
#   are re-used up to 40 times.
#
#   ...
#
# The n1-standard-1 runners seem to be tagged with 'docker' together with 'gce'.
#
# The more powerful n1-standard-2 runners seem to be tagged with
# 'gitlab-org-docker' or some with just 'gitlab-org'.
#
#
# Our current private runner 'docker', 'samba-ci-private', 'shared' and
# 'ubuntu1804'. It runs with an ubuntu1804 kernel and privides an ext4 filesystem
# and similar RAM as the n1-standard-2 runners.
#

.shared_runner_build:
  # We use n1-standard-1 shared runners by default.
  #
  # There are currently 5 shared runners with 'docker' and 'gce',
  # while there are only 2 provising 'docker' together with 'shared'.
  #
  # We used to fallback to our private runner if the docker+shared runners
  # were busy, but now that we use the 5 docker+gce runners, we try to only
  # use shared runners without a fallback to our private runner!
  # Lets see how that will work out.
  tags:
    - docker
    - gce

.shared_runner_test:
  # Currently we're fine using the n1-standard-1 runners also for testing
  extends: .shared_runner_build

.private_runner_test:
  # We use our private runner only for special tests
  tags:
    - docker
    - samba-ci-private