In certain scenarios, accessing the NOM server UI through a reverse proxy is necessary to prevent the NOM server's UI from being exposed externally. You may encounter the following error when trying to access the NOM server UI via the reverse proxy

 

The accessibility of the NOM server UI depends on the configuration of the reverse proxy and the allowed origins settings on the NOM server. 

By default, the allowed origins for the NOM server are set to "http://localhost:[*], https://localhost:[*]."

 

To resolve this, you can add the fully qualified domain name (FQDN) of the reverse proxy to the allowed origins in the NOM server configuration. Additionally, ensure that SSL support is enabled through passthrough on the reverse proxy.

These settings can be applied in the NOM server system service file

--cors.allowed-origins=http://reverse proxy FQDN:[*],https://reverse proxy FQDN:[*]

Alternatively, it can be set as an environment variable in the NOM server system service file

Environment="CORS_ALLOWEDORIGINS: http://reverse proxy FQDN:[*],https://reverse proxy FQDN:[*]"

Reference: https://neo4j.com/docs/ops-manager/current/installation/server/#service