Parallelize test_networking.sh script

The script will run locally on each host and only report its
own status. Ansible will track success on a per-node basis.
Postinstall section now applies to all nodes that run Kubernetes
services.

Change-Id: I84c526f44a3cdb9422ee720a4c148201bdc8b90d

utils/kargo/postinstall.yml

@@ -1,5 +1,5 @@
 ---
-- hosts: kube-master[0]
+- hosts: k8s-cluster
   roles:
     - { role: postinstall, tags: postinstall }
 

utils/kargo/roles/postinstall/tasks/main.yml

@@ -16,6 +16,9 @@
 
 - name: Test networking connectivity
   shell: "bash {{ bin_dir }}/test_networking.sh"
+  environment:
+    ADMIN_IP: "{{ hostvars[groups['kube-master'][0]]['ip'] | default(hostvars[groups['kube-master'][0]]['ansible_default_ipv4']['address']) }}"
+    SLAVE_IPS: "{{ ip }}"
   changed_when: false
   become: no
 
@@ -27,7 +30,11 @@
     group: root
     mode: 0644
   register: dashboard
+  delegate_to: "{{groups['kube-master'][0]}}"
+  run_once: true
 
 - name: Create Kubernetes dashboard
   command: "{{ bin_dir }}/kubectl create -f /etc/kubernetes/kubernetes-dashboard.yml"
   when: dashboard.changed
+  delegate_to: "{{groups['kube-master'][0]}}"
+  run_once: true