Resolve issue with mod_proxy decoding

The Ceph RADOS Gateway uses some unusual URI's for multisite
replication; ensure that mod_proxy passes the 'raw' URI down
to the radosgw http endpoint so that client and server side
signatures continue to match.

This seems quite Ceph specific so the template is specialised
into the charm rather than updated in charm-helpers.

Change-Id: Iede49ba8904500076d53388345e154a3ed18e761
Closes-Bug: 1966669
(cherry picked from commit 7907fa96e9)

templates/openstack_https_frontend.conf

@@ -0,0 +1,37 @@
+{% if endpoints -%}
+{% for ext_port in ext_ports -%}
+Listen {{ ext_port }}
+{% endfor -%}
+{% for address, endpoint, ext, int in endpoints -%}
+<VirtualHost {{ address }}:{{ ext }}>
+    ServerName {{ endpoint }}
+    SSLEngine on
+
+    # This section is based on Mozilla's recommendation
+    # as the "intermediate" profile as of July 7th, 2020.
+    # https://wiki.mozilla.org/Security/Server_Side_TLS
+    SSLProtocol all -SSLv3 -TLSv1 -TLSv1.1
+    SSLCipherSuite ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384
+    SSLHonorCipherOrder off
+
+    SSLCertificateFile /etc/apache2/ssl/{{ namespace }}/cert_{{ endpoint }}
+    # See LP 1484489 - this is to support <= 2.4.7 and >= 2.4.8
+    SSLCertificateChainFile /etc/apache2/ssl/{{ namespace }}/cert_{{ endpoint }}
+    SSLCertificateKeyFile /etc/apache2/ssl/{{ namespace }}/key_{{ endpoint }}
+    ProxyPass / http://localhost:{{ int }}/ nocanon
+    ProxyPassReverse / http://localhost:{{ int }}/
+    ProxyPreserveHost on
+    RequestHeader set X-Forwarded-Proto "https"
+    KeepAliveTimeout 75
+    MaxKeepAliveRequests 1000
+</VirtualHost>
+{% endfor -%}
+<Proxy *>
+    Order deny,allow
+    Allow from all
+</Proxy>
+<Location />
+    Order allow,deny
+    Allow from all
+</Location>
+{% endif -%}