Adding an Apache Reverse Proxy for the Node App Server
I want to add HTTPS support to the node-app server so today I configured an Apache Reverse Proxy to redirect traffic from port 80 and 443 (HTTP and HTTPS) to my node-app which runs on port 3000.
I followed these instructions to install apache2 on my Ubuntu 16.04 Digital Ocean Droplet which contains my Node-App server and then followed some more instructions to configure the reverse proxy itself.
First, install apache2:
sudo apt-get update
sudo apt-get install apache2
Then supress the warnings by configuring the ServerName IP_address in the apache2.conf file.
sudo nano /etc/apache2/apache2.conf
sudo apache2ctl configtest
sudo systemctl restart apache2
Allow Apache through the firewall:
sudo ufw app list
sudo ufw app info "Apache Full"
sudo ufw allow in "Apache Full"
Insall the Apache modules needed for the reverse proxy:
sudo a2enmod proxy
sudo a2enmod proxy_http
sudo a2enmod proxy_balancer
sudo a2enmod lbmethod_byrequests
sudo systemctl restart apache2
Configure the redirect in the default config:
sudo nano /etc/apache2/sites-available/000-default.conf
sudo systemctl restart apache2
This config file now looks like this:
<VirtualHost *:80>
ProxyPreserveHost On
ProxyPass / http://127.0.0.1:3000/
ProxyPassReverse / http://127.0.0.1:3000/
# The ServerName directive sets the request scheme, hostname and port that
# the server uses to identify itself. This is used when creating
# redirection URLs. In the context of virtual hosts, the ServerName
# specifies what hostname must appear in the request's Host: header to
# match this virtual host. For the default virtual host (this file) this
# value is not decisive as it is used as a last resort host regardless.
# However, you must set it for any further virtual host explicitly.
#ServerName www.example.com
#ServerAdmin webmaster@localhost
#DocumentRoot /var/www/html
# Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
# error, crit, alert, emerg.
# It is also possible to configure the loglevel for particular
# modules, e.g.
#LogLevel info ssl:warn
#ErrorLog ${APACHE_LOG_DIR}/error.log
#CustomLog ${APACHE_LOG_DIR}/access.log combined
# For most configuration files from conf-available/, which are
# enabled or disabled at a global level, it is possible to
# include a line for only one particular virtual host. For example the
# following line enables the CGI configuration for this host only
# after it has been globally disabled with "a2disconf".
#Include conf-available/serve-cgi-bin.conf
</VirtualHost>
I tested the redirect and realised I hadn’t actually started the server:
cd node-app/
pm2 start index.js
Now when I access the server’s IP address through a browser without specifying the Port, it defaults to port 80 (HTTP) and I get the Hello World message from my Node-App.
Now to only allow direct access to the Node-App from localhost (add as the second argument in the index.js file):
// Start the server
var server = app.listen(process.env.PORT || 3000, 'localhost', function() {
console.log('Server started on port 3000...');
});
This caused an error due to my automated tests which currently check for a 404 error when trying to send a POST request. A solution was to add ProxyErrorOverride off to the above file as found in this post.
<VirtualHost *:80>
ProxyPreserveHost On
ProxyErrorOverride off
ProxyPass / http://127.0.0.1:3000/
ProxyPassReverse / http://127.0.0.1:3000/
</VirtualHost>