I enjoy using minikube a lot, and I use it for CI at github.com with no problems. I really like to be able to do CI stuff on gitlab as well, but so far no luck with that.

At first the minikube binary will not even run in the Alpine container, so I added libc6-compat

Then I got:
X Exiting due to RSRC_INSUFFICIENT_CORES: Requested cpu count 1 is less than the minimum allowed of 2

Then I changed the minikube start command to
./minikube start --extra-config=kubeadm.ignore-preflight-errors=NumCPU --force --cpus=1

And now it seems to hang forever, last trace line:
! Listening to 0.0.0.0 on external docker host docker. Please be advised

Here is the full modified .gitlab-ci.yml

image: docker:stable
variables:
  KUBECTL: v1.17.0
services:
  - docker:dind
stages:
  - test
test:
  stage: test
  script:
    - apk add -U wget libc6-compat
    - wget -O ./minikube https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64
    - chmod +x ./minikube
    - wget -O ./kubectl https://storage.googleapis.com/kubernetes-release/release/${KUBECTL}/bin/linux/amd64/kubectl
    - chmod +x ./kubectl
    - ./minikube start --extra-config=kubeadm.ignore-preflight-errors=NumCPU --force --cpus=1
    - ./kubectl get nodes -o wide
    - ./kubectl get pods --all-namespaces -o wide
    - ./kubectl get services --all-namespaces -o wide

Any ideas ?