ood-portal-generator should allow for different servername and redirect rules

[wdpypere]

We have a setup with ondemand behind an loadbalancer and proxy host.
The only way (I found) to make all the redirects generated by ood-portal-generator work (as in, point to the proxy) is to set the servername: proxyhostname in /etc/ood/config/ood-portal.yml.

But this also sets the servername in the apache virtualhost to the proxyhost:

<VirtualHost *:443>
  ServerName proxyhostname

Which creates the problem that apache warns that the ServerName and the name in the certificate for the host are different, and there is no valid SSL.

So I think it would be good to have an separate option in /etc/ood/config/ood-portal.yml to set the redirects.

[ericfranz]

The portion of the template that uses @servername is:

ondemand/ood-portal-generator/templates/ood-portal.conf.erb

Lines 49 to 74 in cda8300

	<% if @ssl && @use_rewrites -%>
	# Redirect all http traffic to the https Open OnDemand portal URI
	# http://*:<%= @port %>
	# #=> <%= @ssl ? "https" : "http" %>://<%= @servername || "localhost" %>:<%= @port %>
	#
	<VirtualHost *:80>
	RewriteEngine On
	RewriteRule ^(.*) <%= @ssl ? "https" : "http" %>://<%= @servername || "%{SERVER_NAME}" %>:<%= @port %>$1 [R=301,NE,L]
	</VirtualHost>
	<% end -%>
	# The Open OnDemand portal VirtualHost
	#
	<VirtualHost *:<%= @port %>>
	<%- if @servername -%>
	ServerName <%= @servername %>
	ErrorLog "<%= @logroot %>/<%= @servername %>_error<%= "_ssl" if @ssl %>.log"
	CustomLog "<%= @logroot %>/<%= @servername %>_access<%= "_ssl" if @ssl %>.log" combined
	<%- if @use_rewrites -%>
	RewriteEngine On
	RewriteCond %{HTTP_HOST} !^(<%= @servername %>(:<%= @port %>)?)?$ [NC]
	RewriteRule ^(.*) <%= @ssl ? "https" : "http" %>://<%= @servername %>:<%= @port %>$1 [R=301,NE,L]
	<%- end -%>
	<%- end -%>

So if servername is "proxyhostname" you get:

# Redirect all http traffic to the https Open OnDemand portal URI
#     http://*:443
#     #=> https://proxyhostname:443
#
<VirtualHost *:80>
  RewriteEngine On
  RewriteRule ^(.*) https://proxyhostname:443$1 [R=301,NE,L]
</VirtualHost>

# The Open OnDemand portal VirtualHost
#
<VirtualHost *:443>
  ServerName proxyhostname

  ErrorLog  "logs/proxyhostname_error_ssl.log"
  CustomLog "logs/proxyhostname_access_ssl.log" combined

  RewriteEngine On

# The Open OnDemand portal VirtualHost
#
<VirtualHost *:443>
  ServerName proxyhostname

  ErrorLog  "logs/proxyhostname_error_ssl.log"
  CustomLog "logs/proxyhostname_access_ssl.log" combined

  RewriteEngine On
  RewriteCond %{HTTP_HOST} !^(proxyhostname(:443)?)?$ [NC]
  RewriteRule ^(.*) https://proxyhostname:443$1 [R=301,NE,L]

What would the name of the second option be called, and what would it affect? How would above output look different?

[wdpypere]

@ericfranz I made a PR for this (#74)
The ouput should look like

#
<VirtualHost *:80>
  RewriteEngine On
  RewriteRule ^(.*) https://proxyhostname:443$1 [R=301,NE,L]
</VirtualHost>

<VirtualHost *:443>
  ServerName servername

  ErrorLog  "logs/servername_error_ssl.log"
  CustomLog "logs/servername_access_ssl.log" combined

  RewriteEngine On
  RewriteCond %{HTTP_HOST} !^(proxyhostname(:443)?)?$ [NC]
  RewriteRule ^(.*) https://proxyhostname:443$1 [R=301,NE,L]

[wdpypere]

this enables us to have 1 proxy host and several backend portals, but all served from one URL.