Using become to restart services in handlers.

handlers/main.yml

@@ -1,10 +1,13 @@
 ---
 - name: restart nginx
   service: name=nginx state=restarted
+  become: true
 
 - name: validate nginx configuration
   command: nginx -t -c /etc/nginx/nginx.conf
   changed_when: False
+  become: true
 
 - name: reload nginx
   service: name=nginx state=reloaded
+  become: true