Add support for prometheus

templates/haproxy_cfg.jinja2

@@ -163,6 +163,10 @@ frontend http_in
   acl kibana_present hdr(host) -i -n '{{ kibana_domain|default(inventory_hostname) }}'
   use_backend backend_redirect_ssl if kibana_present
 {% endif %}
+{% for prometheus in prometheus_settings|default([]) %}
+  acl prometheus_{{ prometheus.id }}_present hdr(host) -i -n '{{ prometheus.domain|default(inventory_hostname) }}'
+  use_backend backend_redirect_ssl if prometheus_{{ prometheus.id }}_present
+{% endfor %}
 {% if 'webserver' in groups %}
 {% for host in groups['webserver']|sort %}
   http-request set-header x-routing-host {{ host }} if !letsencrypt_challenge { hdr(x-routing-host) undefined } { hdr(host) -i -n -f /etc/haproxy/{{host}}.list }
@@ -318,6 +322,10 @@ frontend https_in_{{ cert.ip }}
   acl kibana_present hdr(host) -i -n '{{ kibana_domain|default(inventory_hostname) }}'
   use_backend backend_kibana if kibana_present
 {% endif %}
+{% for prometheus in prometheus_settings|default([]) %}
+  acl prometheus_{{ prometheus.id }}_present hdr(host) -i -n '{{ prometheus.domain|default(inventory_hostname) }}'
+  use_backend backend_prometheus_{{ prometheus.id }} if prometheus_{{ prometheus.id }}_present
+{% endfor %}
 {% for external in cert.external|default([]) %}
   acl is_{{ external.key }} {{ external.acl }}
   use_backend backend_{{ external.key }} if is_{{ external.key }}
@@ -527,6 +535,14 @@ backend backend_kibana
 {% endif %}
   server kibana 127.0.0.1:5601 check maxconn 32
 {% endif %}
+{% for prometheus in prometheus_settings|default([]) %}
+
+backend backend_prometheus_{{ prometheus.id }}
+{% if proxy_debug %}
+  http-response set-header X-Proxy-Backend "prometheus_{{ prometheus.id }}"
+{% endif %}
+  server prometheus_{{ prometheus.id }} 127.0.0.1:{{ prometheus.port }} check maxconn 32
+{% endfor %}
 
 backend backend_maintenance
 {% if proxy_debug %}