Add user gitlab-runner to group docker

tasks/main.yml

@@ -30,4 +30,10 @@
         state: present
         update_cache: yes
 
+    - name: Add gitlab-runner to group docker
+      user:
+        name: gitlab-runner
+        groups: docker
+        append: yes
+
   when: not excluded_roles or "gitlab-runner" not in excluded_roles