More improvement to base-test cleanup and post playbooks

We move the disk utilization debugging into the post run playbook as it
isn't really a cleanup item. We may adjust this in the future if we find
that zuul isn't running this aggressively enough when test nodes run out
of disk space.

This leaves the ssh key cleanup as the dedicated task in the cleanup
which is what we want. A small self contained cleanup playbook that
actually cleans things up for subsequent runs.

Change-Id: I0bfbda8e04f43fb5df3475d52d59b1b9ba651037

playbooks/base-test/cleanup.yaml

@@ -1,20 +1,3 @@
-- hosts: all
-  tasks:
-    - name: Gather debug info on job fail
-      when: not (zuul_success | bool)
-      block:
-        - name: get df disk usage
-          raw: timeout -k 5 90 df
-
-        - name: get df inode usage
-          raw: timeout -k 5 90 df -i
-
-        - name: get l2 networking
-          raw: timeout -k 5 90 ip link
-
-        - name: get l3 networking
-          raw: timeout -k 5 90 ip addr
-
 - hosts: all
   # NOTE(pabelanger): We ignore_errors for the following tasks as not to fail
   # successful jobs.

playbooks/base-test/post.yaml

@@ -2,3 +2,22 @@
   roles:
     - fetch-output
     - merge-output-to-logs
+  tasks:
+    - name: Gather debug info on job fail
+      when: not (zuul_success | bool)
+      block:
+        - name: get df disk usage
+          raw: timeout -k 5 90 df
+          failed_when: false
+
+        - name: get df inode usage
+          raw: timeout -k 5 90 df -i
+          failed_when: false
+
+        - name: get l2 networking
+          raw: timeout -k 5 90 ip link
+          failed_when: false
+
+        - name: get l3 networking
+          raw: timeout -k 5 90 ip addr
+          failed_when: false