letsproxy

letsproxy is an easy to use proxy for https data traffic using Let's Encrypt certificates.

Features

• Redirectes requests to http (port 80) to https (port 443)
• Automatically update certificates
• Support websockets
• Proxy target defined in a configuration file

Give node access to use port 80 and 443

Since the proxy needs to listen to port 80 and port 443 which both are below 1024 the node process needs special privileges to avoid having to run as root. These privileges can be given to the node binary using the following command. Please note that this will give all node processes this privileges.

# Not that the node path might be a symlink, you must find the real path 
sudo setcap 'cap_net_bind_service=+ep' /usr/bin/nodejs

Install letsencrypt cli

https://letsencrypt.org/getting-started/

git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt
./letsencrupt-auto

Create certificates

letsencrypt-auto certonly --standalone -d example.com -d www.example.com
 
# /etc/letsencrypt needs to be read and writable as the user running letsproxy 
sudo chmod g+rwx /etc/letsencrypt -R
sudo chown root:$USER /etc/letsencrypt -R
 
# It also seems that you have to symlink the main certificate for all subdomains (Probably letsproxy does something wrong...) 
sudo ln -s /etc/letsencrypt/live/example.com /etc/letsencrypt/live/www.example.com

Create configuration

/etc/letsproxy.json

{
  "https": {
    "dir": "/etc/letsencrypt",
    "key": "live/example.com/privkey.pem",
    "cert": "live/example.com/cert.pem"
  },
  "paths" : {
    "example.com": "localhost:8080",
    "www.example.com": "localhost:8080"
  }
}

Run letsproxy

./bin/letsproxy
 
# Or if running PM2 
pm2 start ./lib/main.js --name LetsProxy

Tips

Print information about certificate

openssl x509 -in /etc/letsencrypt/live/example.com/cert.pem -text -noout

Blocking an external port but allow localhost

iptables -A INPUT ! -s 127.0.0.1 -p tcp -m tcp --dport 8080 -j DROP