Domains
The Domains page lists the domain names that workspaces can publish their URLs under. A domain is a base hostname (for example apps.example.com) that you register with Trailer so that workspace URLs like myapp.apps.example.com can be routed to a running workspace.
What a domain is for
Section titled “What a domain is for”When you give a workspace an external URL, you choose a subdomain, a port, and one of these registered domains. The domain is the part of the address that Trailer routes to the workspace. Registering a domain is what makes it available to pick when defining those URLs, so the domain is the shared, reusable piece and each workspace URL is built on top of one.
Host binding
Section titled “Host binding”A domain belongs to a single host. The same hostname can only be registered once per host, and its URL cannot be changed after creation (create a new one instead).
If you want to publish the same hostname from more than one host, add it again for each host: registering apps.example.com on one host does not make it usable from another. When you define a workspace URL, you can only pick from the domains registered on that workspace’s host.
A domain cannot be deleted while a workspace on its host is using one of its URLs. Remove or repoint those workspace URLs first.
Routing and the reverse proxy
Section titled “Routing and the reverse proxy”A domain does not itself carry routing or proxy settings. How a workspace URL under a domain is served is decided by the address and by the host:
- If the domain is the server’s own address, or a subdomain of it, the workspace is served through Trailer’s built-in proxy.
- Otherwise the workspace is served through the host’s reverse proxy (Traefik), in whichever mode that host is set up for.
For the full picture of how a URL reaches a container and how the serving path is chosen, see Workspace URLs and routing.
Authentication
Section titled “Authentication”Authentication is set on each workspace URL, not on the domain. Every URL you publish can be left open, protected with a username and password, or restricted to specific Trailer users. Because it is per URL, two workspaces sharing the same domain can protect their URLs differently. See Authentication for the options and how they behave.
The table
Section titled “The table”The table shows one row per domain with these columns:
- URL: a link to the domain details.
- Host: the host the domain is available on.
- Last update
You can search by URL, sort by host, URL, or last update, and page through results. A refresh button re-fetches the list.
Actions
Section titled “Actions”- New domain: opens the Create Domain form. This button is shown only to administrators. Domain creation is admin-only in the UI, unlike volumes, networks, and files.
- Delete: available from the row actions when you hold delete permission. Deletion asks for confirmation. A domain cannot be deleted while a workspace on its host is using one of its URLs. Remove or repoint those workspace URLs first.