Support multi node jobs for tox logs

It is possible somebody may want to run tox jobs over multiple nodes.
Check to see if more then one node is in our inventory, if so then add
the inventory_hostname to the log path.

Change-Id: Icd0532cb415fdae42eae6d2269d5a0be5fcdf98a
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

playbooks/tox/post.yaml

@@ -9,14 +9,25 @@
         use_regex: yes
       register: result
 
+    - name: Set tox log path for multiple nodes
+      set_fact:
+        log_path: "{{ zuul.executor.log_root }}/{{ inventory_hostname }}/tox"
+      when: groups['all'] | length > 1
+
+    - name: Set tox log path for single node
+      set_fact:
+        log_path: "{{ zuul.executor.log_root }}/tox"
+      when: log_path is not defined
+
     - name: Ensure local tox dir
       file:
-        path: "{{ zuul.executor.log_root }}/tox"
+        path: "{{ log_path }}"
         state: directory
+      delegate_to: localhost
 
     - name: Collect tox logs
       synchronize:
-        dest: "{{ zuul.executor.log_root }}/tox"
+        dest: "{{ log_path }}"
         mode: pull
         src: "{{ item.path }}/log/"
         verify_host: true