Only upload logs when jobs fail

We're having some major disk issues. Help the situation by only
uploading failure logs.

Change-Id: I4156fb59570d98b16c775752639c2fe23e5777c5

roles/upload-logs/tasks/main.yaml

@@ -2,14 +2,19 @@
   include_role:
     name: set-zuul-log-path-fact
 
-- name: Create log directories
+# NOTE(mordred) Temporary hack to only upload logs on failures to work around
+# unfortunately timed disk outage.
+- when: not zuul_success|bool
+  block:
+
+    - name: Create log directories
       file:
         path: "{{zuul_logserver_root}}/{{ zuul_log_path }}"
         state: directory
         recurse: yes
         mode: 0775
 
-- name: Ensure logs are readable before uploading
+    - name: Ensure logs are readable before uploading
       delegate_to: localhost
       file:
         path: "{{ zuul.executor.log_root }}/"
@@ -17,7 +22,7 @@
         state: directory
         recurse: yes
 
-- name: Upload logs to log server
+    - name: Upload logs to log server
       synchronize:
         src: "{{ zuul.executor.log_root }}/"
         dest: "{{zuul_logserver_root}}/{{ zuul_log_path }}/"
@@ -26,8 +31,8 @@
           - "--exclude=job-output.json"
       no_log: true
 
-# After this point there are no more logs
-- name: gzip console log and json output
+    # After this point there are no more logs
+    - name: gzip console log and json output
       delegate_to: localhost
       archive:
         path: "{{ zuul.executor.log_root }}/{{ item }}"
@@ -35,7 +40,7 @@
         - job-output.txt
         - job-output.json
 
-- name: Upload console log and json output
+    - name: Upload console log and json output
       synchronize:
         src: "{{ zuul.executor.log_root }}/{{ item }}.gz"
         dest: "{{zuul_logserver_root}}/{{ zuul_log_path }}/{{ item }}.gz"