This is a highly recommended reading !
For GeoServer, the proxy base url can be set in the admin UI, via Settings > Global > Proxy URL. This is one of the first thing to do once your geoserver instance is deployed, or you won't be able to add local layers using our viewer.
The proxy base URL should be set to something like this: http(s)://your.server.fqdn/geoserver without a trailing slash. After saving the form, you should check in the WMS capabilities that the service URLs are as expected.
GeoServer uses the fonts available to the JVM for WMS styling through SLD. To get more fonts than what the JVM offers by default, you should install the "core fonts for the web":
sudo apt-get install ttf-mscorefonts-installer
Restart tomcat-geoserver0 and check on the /geoserver/web/?wicket:bookmarkablePage=:org.geoserver.web.admin.JVMFontsPage
page that more fonts are loaded.
By default, GeoServer supports more than 2000 spatial reference systems.
This is really a lot, but you're probably not interested in 99% of them, and they clutter your GetCapabilities documents.
It's easy to restrict the list to the most useful ones: in the WMS and WCS admin pages, fill the "Limited SRS list" textarea with, eg:
2154, 3857, 3942, 3943, 3944, 3945, 3946, 3947, 3948, 3949, 3950, 4171,
4258, 4326, 23030, 23031, 23032, 32630, 32631, 32632, 4171, 4271, 3758
... and don't forget to submit the form.
For the standalone GeoWebCache, the proxy should be automatically configured (via gwc.properties).
On the /geonetwork/srv/eng/config
page, you should:
- fill the "Site" and "Server" sections.
In the server section, fill the fields according to your setup, eg:
Preferred Protocol HTTP
Host sdi.georchestra.org
Port 80 
Secure Port  8443
- enable "XLINK RESOLVER"
- enable INSPIRE + search panel
- check "use Proxy" in case your connection to the internet is proxied
- set feedback email
In GeoFence, you should configure your geoserver instance with:
- instance name = default-gs
- description = my geoserver instance
- base url = http://my.sdi.org/geoserver
- username = geoserver_privileged_user
- password = the LDAP password of the above user, which should be the same as the one referenced in your config.