ansible-scylla-node: Improves "legacy" support for 'node-exporter'

This patch improves how 'node_exporter_install' is called and how 'node-exporter' service is started.

Fixes: scylladb#249

Signed-off-by: Eduardo Benzecri <[email protected]>

Author: ebenzecri

ansible-scylla-node/handlers/main.yml

@@ -24,12 +24,21 @@
     name: scylla-server
     state: stopped
 
-- name: node_exporter start
+- name: Enable and start 'node-exporter.service' service (legacy)
+  block:
+  - name: Disable and stop 'scylla-node-exporter.service' service
+    ansible.builtin.service:
+      name: scylla-node-exporter.service
+      state: stopped
+      enabled: no
+    when: ansible_facts.services["scylla-node-exporter.service"] is defined
+
+  - name: Enable and start 'node-exporter.service' service (legacy)
+    ansible.builtin.service:
+      name: node-exporter.service
+      state: started
+      enabled: yes
   become: true
-  service:
-    name: node-exporter
-    state: started
-    enabled: yes
 
 - name: Enable and start 'scylla-node-exporter.service' service
   block:

ansible-scylla-node/tasks/common.yml

@@ -114,15 +114,15 @@
   become: true
   when: skip_ntp is defined and skip_ntp|bool == false
 
-- name: node exporter setup
+- name: Run 'node_exporter_install' (legacy)
   shell: |
     node_exporter_install --force
-  when: install_type == 'online'
   become: true
   notify:
-    - node_exporter start
-  ignore_errors: true
-  #TODO: stop ignoring errors when the node_exporter_install script fix is available in all actual versions, resp. use only for < 5.0 / 2022
+    - Enable and start 'node-exporter.service' service (legacy)
+  when:
+    - install_type == 'online'
+    - ansible_facts.services["scylla-node-exporter.service"] is not defined
 
 - name: configure Scylla
   shell: |