Using Wildcard Domains

DockFlare supports using wildcard domains (e.g., *.example.com) to route traffic for multiple subdomains to a single service. This is particularly useful for applications that handle dynamic subdomains, such as multi-tenant services or personal dashboards like Heimdall.

How It Works

When you use a wildcard hostname, Cloudflare Tunnel will route all traffic for any subdomain that doesn't have a more specific DNS record to the service you specify.

For example, if you configure *.apps.example.com, traffic for service1.apps.example.com, service2.apps.example.com, and so on will all be routed to the same destination container.

Important Considerations

Unlike regular hostnames, DockFlare cannot automatically create DNS records for wildcard domains. You must create the wildcard DNS record manually in your Cloudflare dashboard.

DockFlare will still resolve the wildcard hostname to the correct account zone and manage the ingress rule in your Cloudflare Tunnel, but it will skip automatic DNS creation and deletion. Wildcard DNS remains manually owned.

Step-by-Step Guide

Here is how to correctly set up a wildcard domain with DockFlare, using *.plex.example.com as an example.

Step 1: Manually Create the Wildcard DNS Record

1. Log in to your Cloudflare Dashboard.
2. Navigate to the DNS settings for your domain.

3. Click Add record and create a CNAME record with the following details:

   • Type: CNAME
   • Name: *.plex (or just * if your main domain is plex.example.com)
   • Target: Your tunnel's public hostname. You can find this in your Cloudflare Zero Trust dashboard under Access -> Tunnels. It will look something like your-tunnel-uuid.cfargotunnel.com.
   • Proxy status: Make sure it is Proxied (orange cloud).

   This manual DNS record tells Cloudflare to send all traffic for *.plex.example.com to your tunnel.

Step 2: Configure Your Service with a Wildcard Label

Now, configure your service in your docker-compose.yml file with a wildcard hostname label.

services:
  my-proxy-manager:
    image: nginxproxymanager/nginx-proxy-manager
    restart: unless-stopped
    networks:
      - cloudflare-net
    labels:
      - "dockflare.enable=true"
      # Use the wildcard hostname here
      - "dockflare.hostname=*.plex.example.com"
      - "dockflare.service=http://my-proxy-manager:81"

Step 3: Deploy and Verify

1. Save your docker-compose.yml file and run docker compose up -d.
2. DockFlare will detect the container and create an ingress rule in your Cloudflare Tunnel for the hostname *.plex.example.com.
3. You can verify this in the DockFlare Web UI and in your tunnel's configuration in the Cloudflare dashboard.

Now, any request to a subdomain like sonarr.plex.example.com or radarr.plex.example.com will be routed through your Cloudflare Tunnel to your my-proxy-manager container, which can then handle the traffic accordingly.