Only run once our delegate_to locahost commands

In a multi node setup, we only want this logic to be run one across
all hosts.

Change-Id: I4ebb62f76d4ff7363635bee7073c2d7e8f0ad70e
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

roles/add-build-sshkey/tasks/create-key-and-replace.yaml

@@ -1,6 +1,7 @@
 - name: Create Temp SSH key
   command: ssh-keygen -t rsa -b 1024 -N '' -f {{ zuul_temp_ssh_key }}
   delegate_to: localhost
+  run_once: true
 
 - name: Distribute it to all nodes
   authorized_key:
@@ -11,10 +12,12 @@
 - name: Remove all keys from local agent
   command: ssh-add -D
   delegate_to: localhost
+  run_once: true
 
 - name: Add back temp key
   command: ssh-add {{ zuul_temp_ssh_key }}
   delegate_to: localhost
+  run_once: true
 
 - name: Verify we can still SSH to all nodes
   ping:

roles/add-build-sshkey/tasks/main.yaml

@@ -3,6 +3,7 @@
     path: "{{ zuul_temp_ssh_key }}"
   register: zuul_temp_ssh_key_stat
   delegate_to: localhost
+  run_once: true
   failed_when: false
 
 - name: Create a new key in workspace based on build UUID