docker-dotclear/www/servers/subdomain.conf

# docker-dotclear:*
# /var/www/dotclear/servers/subdomain.conf
# Nginx server by subdomains

server {
    # By default, server URLs look like:
    # - http://default.domain.tld/
    # - http://blog2.domain.tld/
    # - ...
    server_name ~^(?<dc_blog_id>\w*?)?\.?(\w+\.\w+)$;

    # Redirect a particular subdomain
    if ($dc_blog_id = 'blog') {
            set $dc_blog_id default;
    }

    # To use custom configuration only use
    # include /etc/nginx/snippets/snippets_common.conf;
    # Adapt to your needs here the content of
    # /etc/nginx/snippets/snippets_subdomain.conf
    # Then disable the Dotclear plugin DockerDotclear
    # (or change their settings)
    include /etc/nginx/snippets/snippets_subdomain.conf;
    include /etc/nginx/snippets/snippets_common.conf;
}