nginx.tmpl

# HTTP 1.1 support
proxy_http_version 1.1;
proxy_buffering off;
proxy_set_header Host $http_host;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

server {
    server_name _;
    listen 80;
    access_log /var/log/nginx/access.log;
    return 503;
}

{{ range $host, $containers := groupByLabel $ "lb.vhost" }}

upstream {{ $host }} {
    {{ range $container := $containers }}
        {{ $addrLen := len $container.Addresses }}
        {{ if eq $addrLen 1 }}
            {{ $address := index $container.Addresses 0 }}
    server {{ $address.HostIP }}:{{ $address.HostPort }};
        {{ else }}
            {{ $port := coalesce $container.Labels.lb.servicePort "80" }}
            {{ $address := where $container.Addresses "Port" $port | first }}
    server {{ $address.HostIP }}:{{ $address.HostPort }};
        {{ end }}
    {{ end }}
}

server {
    server_name {{ $host }};
    listen 80;
    access_log /var/log/nginx/{{ $host }}-access.log;

    location / {
        proxy_pass http://{{ trim $host }};
    }
}
{{ end }}