I've setup jenkins behind a reverse proxy with nginx. ALMOST everything works.
Here is a list of what doesn't, though that may be incomplete

1. accessing "manage plugins" (see attached jenkins.redirects.txt). Although the url is correct (http://jenkins:9090/pluginManager) browser receives a 302 to http://jenkins/pluginManager. If then I manually change the url to http://jenkins:9090/pluginManager, I can access Manage Plugins
2. the same thing happens with Credentials, Configure Global Security and when saving a job configuration. In particular, the configuration is saved but the browser is wrongly redirected

Find attached my nginx configuration, which should be ok