Using fetch GIT_STRATEGY in GitLab-CI with Docker

GitLab CI/CD
1

Hello,

There is GitLab-CI configured for the project.

At the moment each commit triggers repository cloning from scratch.
There is an amount of jobs for building and each performs git clone.

What I want to have is to avoid cloning and to do git fetch.

Regarding configuration:

There are several remote virtual machines, each running GitLab-runner.

[[runners]]
  name = "here_is_name"
  url = "https://here_is_url"
  token = "here_is_token"
  executor = "docker"
  [runners.docker]
    tls_verify = false
    image = "bionic"
    dns = ["10.171.10.1", "10.171.10.2"]
    dns_search = ["openstacklocal"]
    privileged = false
    disable_entrypoint_overwrite = false
    cap_add = ["SYS_PTRACE", "SYS_NICE"]
    oom_kill_disable = false
    disable_cache = true
    volumes = ["/cache", "/my_mounted_folder:ro"]
    pull_policy = "never"
    shm_size = 0
  [runners.cache]
    [runners.cache.s3]
    [runners.cache.gcs]

Some lines from .gitlab-ci.yml:

variables:
    GIT_STRATEGY: fetch
    GIT_SUBMODULE_STRATEGY: normal
	
stages: [ build, test, deploy, post ]

build:gcc:my_binary:
    only: [ master]
    stage: build
    artifacts:
        paths: [ cmake_build/bin/my_binary ]
        expire_in: 1h
    script: |
        mkdir cmake_build
        cd cmake_build
        cmake ../
        make -j16 my_binary

As I understand the feature I’m looking for is somehow related to caching functionality, but behavior is not changed whether I set disable_cache to false or not…

And the other question not clear for me is where repository will be stored in time between different runs if Docker is used to perform the job on.

Looking forward to any suggestion regarding what might be wrong. Thanks.