In environments where local network policy or firewalls require use of an upstream http proxy / cache, Sakai needs to be configured to use this.
Otherwise, components or services which use http requests, such as BasicNewsService for RSS feeds in the News tool, cannot retrieve data from the target URLs. RSS feeds then do not display in the news tool, and it is not possible to add new news channels.
This can be fixed by adding these lines to the Sakai local startup script (e.g. /etc/rc.d/sakai), or to a Sakai startup script such as startup.sh or catalina.sh:
JAVA_OPTS="-DproxySet=true -DproxyHost=cache.some.domain -DproxyPort=8080"
The above information should be added to the Sakai installation documentation.
As local proxy settings are a local system configuration issue (similar to local mail relay details for example), there may also be merit in making this configurable in sakai.properties, and set at startup time or within the appropriate services using code such as:
System.getProperties().put( "proxySet", "true" );
System.getProperties().put( "proxyHost", "some_proxy" );
System.getProperties().put( "proxyPort", "8080" );