Add support for kubectl connection

This change enable using the base job with a kubectl host where
the prepare-workspace can't be use.

Change-Id: Idb5afc38a23d1dcfa63727ef93f9216179481fea

playbooks/base/pre.yaml

@@ -1,10 +1,20 @@
+- hosts: all
+  tasks:
+    - block:
+        - import_role: name=add-build-sshkey
+        - import_role: name=prepare-workspace
+        # This role ensures basic connectivity and produces some
+        # helpful information in zuul-info/
+        - import_role: name=validate-host
+      when: "ansible_connection != 'kubectl'"
+    - block:
+        - import_role: name=remove-zuul-sshkey
+        - import_role: name=prepare-workspace-openshift
+          run_once: true
+      when: "ansible_connection == 'kubectl'"
+
 - hosts: all
   roles:
-    - add-build-sshkey
-    - prepare-workspace
-    # This role ensures basic connectivity and produces some
-    # helpful information in zuul-info/
-    - validate-host
     # This role ensures standard output directories are created
     # on each remote node
     - ensure-output-dirs