ci: use dind for building docker images

.gitlab-ci.yml

@@ -22,6 +22,10 @@ build:npm:
 build:docker-builder:
   image: docker:stable
   stage: build
+  variables:
+    DOCKER_DRIVER: overlay2
+  services:
+    - docker:dind
   script:
     - cd images/builder
     - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN registry.gitlab.com
@@ -33,6 +37,10 @@ build:docker-builder:
 build:docker-node:
   image: docker:stable
   stage: build
+  variables:
+    DOCKER_DRIVER: overlay2
+  services:
+    - docker:dind
   script:
     - cd images/node
     - docker login -u gitlab-ci-token -p $CI_BUILD_TOKEN registry.gitlab.com/openstapps/projectmanagement/