I figured out a solution. I just needed to prevent the web installer from starting up and claiming the 0.0.0.0:4567 address the nodebb server tries to use.

The Web Installer only starts if there isn't already a config.json file. So I added a ConfigMap to my kubernetes manifest to insert a valid config.json file into the correct directory when the nodebb pod starts. I used this post for guidance in setting up the ConfigMap.

Thanks for your help!