Add playbook to graceful restart zuul-launchers

We'll wait up to 3hr 10mins for zuul-launchers to shutdown.

Change-Id: I880748704b6cae5a25c21326d6374ac71f4c9e1a
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

playbooks/restart_zuul_launchers.yaml

@@ -0,0 +1,23 @@
+---
+- hosts: 'zlstatic0*.openstack.org:zl0*.openstack.org'
+  # Do the entire play completely for one host at a time
+  serial: 1
+  any_errors_fatal: true
+  tasks:
+    - name: Graceful stop zuul-launcher
+      shell: 'zuul-launcher graceful'
+      become: true
+      become_user: zuul
+
+    - name: Wait for (3h10m) to stop zuul-launcher
+      async: 11400
+      poll: 60
+      wait_for:
+        path: /var/run/zuul-launcher/zuul-launcher.pid
+        state: absent
+        timeout: 11400
+
+    - name: Restart zuul-launcher
+      service:
+        name: zuul-launcher
+        state: restarted