Add monitor.pl metrics exporters to web servers

[daaang]

No description provided.

[daaang]

In case anybody is curious, this is what the apache::vhost resource creates:

# ************************************
# Vhost template in module puppetlabs-apache
# Managed by Puppet
# ************************************
#
<VirtualHost *:9180>
  ServerName prometheus-webserver-exporter

  ## Vhost docroot
  DocumentRoot "/usr/local/lib/prom_web_exporter"
  ## Alias declarations for resources outside the DocumentRoot
  ScriptAlias / "/usr/local/lib/prom_web_exporter/"

  ## Directories, there should at least be a declaration for /usr/local/lib/prom_web_exporter

  <Directory "/usr/local/lib/prom_web_exporter">
    Options Indexes FollowSymLinks MultiViews
    AllowOverride None
    Require all granted
  </Directory>

  ## Logging
  ErrorLog "/var/log/apache2/prometheus-webserver-exporter_error.log"
  ServerSignature Off
  CustomLog "/var/log/apache2/prometheus-webserver-exporter_access.log" combined
  ## Rewrite rules
  RewriteEngine On

  RewriteRule ^/$ /metrics [last,redirect=permanent]

  ## Shibboleth
</VirtualHost>

[skorner]

Not sure if you can override the default Options for the doc root, but if you can this vhost can function with None.

[skorner]

This approach to, and first pass at, replicating the legacy web server monitoring that haproxy relies on to a prometheus exporter looks great to me.