conf/dev/default.conf

types {
    text/tab-separated-values tsv;
}

server {
    listen       80;
    listen  [::]:80;
    server_name  localhost;
    gzip on;
    gzip_types text/plain text/tab-separated-values application/json;
    gzip_min_length 102400; # 100KB
    gzip_comp_level 6;
    gzip_proxied any;
    gzip_disable "msie6";
    sendfile on;
    tcp_nopush on;

    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;

        # Enable CORS for specific origin and allow credentials
        add_header 'Access-Control-Allow-Origin' '*' always;
        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, PUT, DELETE';
        add_header 'Access-Control-Allow-Headers' 'Origin, X-Requested-With, Content-Type, Accept, Authorization';
        add_header 'Access-Control-Allow-Credentials' 'true' always;
        add_header 'Access-Control-Expose-Headers' 'Content-Range' always;

        # Handle preflight requests
        if ($request_method = OPTIONS) {
            add_header 'Access-Control-Allow-Origin' '*';
            add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS, PUT, DELETE';
            add_header 'Access-Control-Allow-Headers' 'Origin, X-Requested-With, Content-Type, Accept, Authorization';
            add_header 'Access-Control-Allow-Credentials' 'true';
            add_header 'Access-Control-Expose-Headers' 'Content-Range';
            return 204;
        }
    }

    # redirect server error pages to the static page /50x.html
    #
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }
}