This Google search: https://www.google.co.uk/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=couchbase%20non%20root
Should come up with this page: http://developer.couchbase.com/documentation/server/4.5/install/rhel-suse-install-intro.html#topic8026__rh-nonroot-nonsudo-