handle version upgrades; new handler handling

handlers/main.yml

@@ -2,8 +2,12 @@
   systemd:
     name: nebula
     state: restarted
+  when: inventory_hostname not in groups['nebula_lighthouse']
+  listen: "restart nebula"
 
 - name: Restart Lighthouse
   systemd:
     name: lighthouse
     state: restarted
+  when: inventory_hostname in groups['nebula_lighthouse']
+  listen: "restart nebula"

tasks/lighthouse.yml

@@ -18,7 +18,7 @@
     owner: root
     group: root
     mode: '0400'
-  notify: Restart Lighthouse
+  notify: restart nebula
 
 - name: Ensure lighthouse service exists
   template:

tasks/nebula.yml

@@ -6,12 +6,30 @@
     owner: root
     group: root
 
+- name: Check for existing Nebula install
+  stat:
+    path: '/opt/nebula/nebula'
+  register: installed_nebula_stats
+
+- name: Get Nebula version (if installed)
+  command: "/opt/nebula/nebula -version"
+  register: installed_nebula_version_out
+  changed_when: False
+  failed_when: False
+  when: installed_nebula_stats.stat.exists
+
+- name: Extract Nebula version from command output
+  set_fact:
+    installed_nebula_version: "{{ installed_nebula_version_out.stdout.split(' ')[1] }}"
+  when: installed_nebula_stats.stat.exists
+
 - name: Download & Extract Nebula
   unarchive:
     src: "https://github.com/slackhq/nebula/releases/download/v{{ nebula_version }}/nebula-linux-{{ nebula_architectures[ansible_architecture] }}.tar.gz"
     dest: "/opt/nebula"
     remote_src: yes
-    creates: '/opt/nebula/nebula'
+  when: (installed_nebula_version|default(nebula_version) != nebula_version) or (not installed_nebula_stats.stat.exists)
+  notify: restart nebula
 
 - name: Ensure Nebula binaries permissions are correct
   file:

tasks/node.yml

@@ -46,7 +46,7 @@
     owner: root
     group: root
     mode: '0400'
-  notify: Restart Nebula
+  notify: restart nebula
 
 - name: Ensure Nebula service exists
   template: