Getting warning message about incorrect HTTP proxy

Hi Tuan,

This warning indicates a mismatch between the Host header received by the TeamCity server and what it expects. This typically occurs when TeamCity is behind a proxy server (e.g., Nginx, Apache) that isn't configured correctly.

> Or is this OK to ignore the warning message?

In test or development environments, if everything is functioning normally and you’re not using links in notifications, webhooks, or external reverse proxy access, it may be safe to ignore the warning.

However, in production or shared environments, it's not recommended to ignore this message, as it can lead to:

- Incorrect URL generation (e.g., in email notifications or REST responses)

- Redirect issues

- Integration problems

You likely have a reverse proxy setup (or are accessing TeamCity through a DNS name), but TeamCity is binding to or referencing 127.0.0.1.

Replace localhost(127.0.0.1) and port with the actual DNS name and port used to access the TeamCity web UI in browsers. Reference: TeamCity Configuration and Maintenance - Build Settings.

Make sure this matches how users access the TeamCity web UI in their browsers (DNS name or IP + port).

If you're using a reverse proxy such as Nginx or Apache, make sure to forward the correct headers.

Nginx example:

location / {
    proxy_pass         http://127.0.0.1:8111;
    proxy_set_header   Host $host;
    proxy_set_header   X-Forwarded-Host $host;
    proxy_set_header   X-Forwarded-Server $host;
    proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
}

Ensure that $host reflects the external DNS name used to access TeamCity.

Reference: Configuring Proxy Server - TeamCity Docs.

Best Regards,

Tom