Node.js Best Practices — Nginx

Like any kind of apps, JavaScript apps also have to be written well.

Otherwise, we run into all kinds of issues later on.

In this article, we’ll look at some best practices we should follow when writing Node apps.

Adding a Reverse Proxy with Nginx

We should never expose our Express app directly to the Internet.

Instead, we should use a reverse proxy to direct traffic to our app.

This way, we can add caching, control our traffic, and more.

We can install it by running:

apt update
apt install nginx

Then we can start it by running:

systemctl start nginx

Once we have Nginx running, we can go into /etc/nginx/nginx.conf to change the Nginx config to point to our app.

For example, we can write:

server {
  listen 80;
  location / {
     proxy_pass http://localhost:3000;
  }
}

We use the proxy_pass directive to pass any traffic from port 80 to our Express app, which is listening to port 3000.

Then we restart Nginx to make our config take effect by running:

systemctl restart nginx

Load Balancing with Nginx

To add load balancing with Nginx, we can edit the nginx.conf by writing:

http {
  upstream fooapp {
    server localhost:3000;
    server domain2;
    server domain3;
    ...
  }
  ...
}

to add the instances of our app.

The upstream section creates a server group that will load balance traffic across the servers we specify.

Then in the server section, we add:

server {
   listen 80;
   location / {
     proxy_pass http://fooapp;
  }
}

to use the fooapp server group.

Then we restart Nginx with:

systemctl restart nginx

Enabling Caching with Nginx

To enable caching, we can use the proxy_cache_path directive.

In nginx.conf , we write:

http {
  proxy_cache_path /data/nginx/cache levels=1:2   keys_zone=STATIC:10m
  inactive=24h max_size=1g;
  ...
}

We cache for 24 hours with the max cache size set to 1GB.

Also, we add:

server {
   listen 80;
   location / {
     proxy_pass            http://fooapp;
     proxy_set_header      Host $host;
     proxy_buffering       on;
     proxy_cache           STATIC;
     proxy_cache_valid     200 1d;
     proxy_cache_use_stale error timeout invalid_header updating
            http_500 http_502 http_503 http_504;
  }
}

proxy_buffering set to on to add buffering.

proxy_cache is set to STATIC to enable the cache.

proxy_cache_valid sets the cache to expire in 1 day is the status code is 200.

proxy_cache_use_stale determines when a stale cached response can be used during communication.

We set it to be used when there’s a timeout error, invalid header error when the current is updated with the updating keyword.

We also can use the cache if the response status code is 500, 502, 503, or 504.

Enabling Gzip Compression with Nginx

We can enable Gzip compression with Nginx by using the gzip modules.

For instance, we can write:

server {
   gzip on;
   gzip_types      text/plain application/xml;
   gzip_proxied    no-cache no-store private expired auth;
   gzip_min_length 1000;
  ...
}

in nginx.conf to enable Gzip with gzip on .

gzip_types lets us set the MIME type for files to zip.

gzip_proxied lets us enable or disable gzipping on proxied requests.

We enable it with the private, expired, no-cache and no-store Cache-Control header values.

auth means we enable compression if a request header enables the Authorization field.

gzip_min_length means we set the minimum length of the response that will be gzipped.

The length is Content-Length response header field and it’s in bytes.

Conclusion

There’re many things we can do with Nginx to improve the performance of our apps.