set prometheus external url

inventories/group_vars/prometheus/vars.yml

 telegraf_prometheus_client_listen_address: localhost
 
 prometheus_version: 2.33.3
+prometheus_url: "http://{{ ansible_fqdn }}"
 prometheus_telegraf_hosts: "{{ groups.all }}"
 
 prometheus_username: prometheus

inventories/group_vars/prometheus_haproxy/prometheus.yml

+prometheus_url: "https://prometheus.neutrinet.be"
 prometheus_telegraf_hosts:
   - "{{ inventory_hostname }}"
   - vpn.neutri.net

roles/prometheus/defaults/main.yml

 prometheus_version: 2.33.3
+prometheus_url: "https://{{ ansible_fqdn }}"
 prometheus_telegraf_hosts: "{{ groups.all }}"
 prometheus_username: prometheus
 prometheus_password: neutrinet

roles/prometheus/templates/systemd/prometheus.service.j2

@@ -13,6 +13,7 @@ ExecStart=/usr/local/bin/prometheus \
   --storage.tsdb.path={{ prometheus_storage_path }} \
   --storage.tsdb.retention.time={{ prometheus_storage_retention }} \
   --web.listen-address='localhost:9090' \
+  --web.external-url='{{ prometheus_url }}' \
 {% if not prometheus_remote_write_url %}
 {# If we did NOT provide a remote write url, that means we are the receiver #}
   --web.enable-remote-write-receiver \