nginx setting for LTI reverse proxy

lti-nginx.conf

server {
    listen 80;
    listen [::]:80;
    server_name lti.nyoho.jp;
    root /var/www/lti.nyoho.jp;
    location /.well-known/acme-challenge/ { allow all; }
    location / { return 301 https://$host$request_uri; }
}

server {
    listen 443 ssl;

    ssl on;
    ssl_certificate /etc/letsencrypt/live/lti.nyoho.jp/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/lti.nyoho.jp/privkey.pem;

    server_name lti.nyoho.jp;

    ssl_session_timeout 5m;

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    # ssl_ciphers "HIGH:!aNULL:!MD5 or HIGH:!aNULL:!MD5:!3DES";
    ssl_ciphers EECDH+AES128:RSA+AES128:EECDH+AES256:RSA+AES256:EECDH+3DES:RSA+3DES:!MD5;
    ssl_prefer_server_ciphers on;
    ssl_session_cache shared:SSL:128m;
    ssl_dhparam /etc/nginx/ssl/dhparam.pem;
    add_header Strict-Transport-Security 'max-age=31536000; includeSubDomains;';

    # TODO: add always
    add_header X-Content-Type-Options "nosniff";
    # add_header X-Frame-Options "SAMEORIGIN";

    # add_header X-Xss-Protection "1";
    # add_header Content-Security-Policy "default-src 'self'";

    ssl_stapling on;
    ssl_stapling_verify on;
    ssl_trusted_certificate /etc/letsencrypt/live/lti.nyoho.jp/fullchain.pem;
    resolver 8.8.8.8;

    location / {
        proxy_set_header        Host $host;
        proxy_set_header        X-Real-IP $remote_addr;
        proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header        X-Forwarded-Proto $scheme;
        proxy_pass http://localhost:18888;
    }

    access_log /var/log/nginx/lti-access.log ltsv;
    error_log /var/log/nginx/lti-error.log;
}