Most settings are made once by the installer. Since v0.4.0 the language model is chosen in Settings, not here. harbor config edits the file; harbor start applies it.
Optional. A Tailscale auth key, for Tailscale running as one of Harbor's containers. With it the vault is reachable only on your tailnet, over HTTPS, and nothing listens on the machine's own interfaces. Needed only on first start.
TAILSCALE_HOSTNAME
The name the vault takes in your tailnet.
HARBOR_DOMAIN
For the internet: the domain the vault is served at, over HTTPS.
HARBOR_PROXY
With HARBOR_DOMAIN: caddy answers on ports 80 and 443 with a Let's Encrypt certificate; own leaves that to a reverse proxy already on the machine, which forwards to HARBOR_WEB_PORT on 127.0.0.1.
HARBOR_SETUP_TOKEN
With caddy: the token in the setup link. The first account can only be created through /setup?token= with it. Generated by the installer.
WEB_ORIGIN
The address the vault is reached at, such as https://harbor.example.com or https://harbor.your-tailnet.ts.net. Sign-ins from any other address are refused.
HARBOR_BIND, HARBOR_WEB_PORT
On your own network, the address and port to publish on: a LAN address, or the address a VPN you run gives the box. Default 127.0.0.1:3000.