Does this fix anything?

.drone.yml

@@ -20,3 +20,19 @@ steps:
         - push
         - tag
       branch: master
+    volumes:
+      - name: dockersock
+        path: /var/run
+
+# Specify docker:dind as a service
+services:
+  - name: docker
+    image: docker:dind
+    privileged: true
+    volumes:
+      - name: dockersock
+        path: /var/run
+
+volumes:
+  - name: dockersock
+    temp: {}