Add a flag to disable no_log on upload-logs

So that it is possible to debug this role, add a flag which disables
setting no_log on the synchronize task.

Change-Id: Ie433ada5ff6cb15b68f19e8678244af9ce9faa13
Depends-On: https://review.openstack.org/556881

roles/upload-logs/README.rst

@@ -13,6 +13,14 @@ This uploads logs to a static webserver using SSH.
 
    The root path to the logs on the logserver.
 
+.. zuul:rolevar:: zuul_log_verbose
+   :default: false
+
+   The synchronize task in this role outputs a lot of information.  By
+   default, no_log is set to avoid overwhelming a reader of the logs.
+   Set this to true to disable that behavior if it becomes necessary
+   to debug this role.
+
 .. zuul:rolevar:: zuul_site_upload_logs
    :default: true
 

roles/upload-logs/tasks/main.yaml

@@ -29,7 +29,7 @@
         rsync_opts:
           - "--exclude=job-output.txt"
           - "--exclude=job-output.json"
-      no_log: true
+      no_log: "{{ not zuul_log_verbose }}"
 
     # After this point there are no more logs
     - name: gzip console log and json output

roles/upload-logs/vars/main.yaml

@@ -1 +1,2 @@
 zuul_logserver_root: /srv/static/logs
+zuul_log_verbose: false