prometheus: Switch to direct systemd command handling w/o conf.d

prometheus/handlers/main.yml

 ---
 
+- name: Reload systemd
+  systemd:
+    daemon_reload: true
+
 - name: Restart prometheus
   systemd:
     name: prometheus.service

prometheus/tasks/main.yml

@@ -29,11 +29,24 @@
     - prometheus
     - config
 
+- name: Create systemd unit override directory
+  file:
+    path: /etc/systemd/system/prometheus.service.d
+    state: directory
+    owner: root
+    group: root
+    mode: "0755"
+  when: ansible_distribution == "Gentoo"
+  tags:
+    - promtheus
+    - config
+
 - name: Configure prometheus command arguments
   template:
-    src: confd-prometheus.j2
-    dest: /etc/conf.d/prometheus
+    src: override.conf.j2
+    dest: /etc/systemd/system/prometheus.service.d/override.conf
   notify:
+    - Reload systemd
     - Restart prometheus
   when: ansible_distribution == "Gentoo"
   tags:

prometheus/templates/confd-prometheus.j2

-# arguments for Prometheus
-command_args="{{ prometheus_args }}"
-supervisor="supervise-daemon"

prometheus/templates/override.conf.j2

+[Service]
+ExecStart=
+ExecStart=/usr/bin/prometheus {{ prometheus_args }}