make systemd socket activation optional

roles/node_exporter/defaults/main.yml

@@ -30,3 +30,4 @@ node_exporter_disabled_collectors: []
 node_exporter_binary_install_dir: "/usr/local/bin"
 node_exporter_system_group: "node-exp"
 node_exporter_system_user: "{{ node_exporter_system_group }}"
+node_exporter_systemd_socket_activation: false

roles/node_exporter/meta/argument_specs.yml

@@ -81,3 +81,7 @@ argument_specs:
           - "I(Advanced)"
           - "Node exporter user"
         default: "node-exp"
+      node_exporter_systemd_socket_activation:
+        description:
+          - "Node exporter systemd socket activation task is executed when set to true."
+        default: false

roles/node_exporter/tasks/configure.yml

@@ -16,6 +16,7 @@
     group: root
     mode: 0644
   notify: restart node_exporter
+  when: node_exporter_systemd_socket_activation
 
 - name: Create node_exporter config directory
   ansible.builtin.file:

roles/node_exporter/templates/node_exporter.service.j2

@@ -3,13 +3,18 @@
 [Unit]
 Description=Prometheus Node Exporter
 After=network-online.target
+{%   if  node_exporter_systemd_socket_activation %}
 Requires=node_exporter.socket
+{%   endif -%}
 
 [Service]
 Type=simple
 User={{ node_exporter_system_user }}
 Group={{ node_exporter_system_group }}
-ExecStart={{ node_exporter_binary_install_dir }}/node_exporter --web.systemd-socket \
+ExecStart={{ node_exporter_binary_install_dir }}/node_exporter \
+{%   if  node_exporter_systemd_socket_activation %}
+--web.systemd-socket \
+{%   endif -%}
 {% for collector in node_exporter_enabled_collectors -%}
 {%   if not collector is mapping %}
     '--collector.{{ collector }}' \