Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -23,8 +23,12 @@ default:
   before_script:
     - docker info
 variables:
-  DOCKER_HOST: tcp://docker:2375
-  DOCKER_TLS_CERTDIR: ""
+  DOCKER_TLS_CERTDIR: "/certs"
+  # These are usually specified by the entrypoint, however the
+  # Kubernetes executor doesn't run entrypoints
+  # https://gitlab.com/gitlab-org/gitlab-runner/-/issues/4125
+  DOCKER_TLS_VERIFY: 1
+  DOCKER_CERT_PATH: "$DOCKER_TLS_CERTDIR/client"
 stages:          # List of stages for jobs, and their order of execution
   - build
   - test