# Configuring HAProxy¶

A modern public-facing website should these days be served via encrypted connections. So https: rather than http: for the website and wss: rather than vs ws: for websocket connections used by webclient.

The reason is security - not only does it make sure a user ends up at the right site (rather than a spoof that hijacked the original’s address), it stops an evil middleman from snooping on data (like passwords) being sent across the wire.

Evennia itself does not implement https/wss connections. This is something best handled by dedicated tools able to keep up-to-date with the latest security practices.

So what we’ll do is install proxy between Evennia and the outgoing ports of your server. Essentially, Evennia will think it’s only running locally (on localhost, IP 127.0.0.1) while the proxy will transparently map that to the “real” outgoing ports and handle HTTPS/WSS for us.

         Evennia
|
(inside-only local IP/ports serving HTTP/WS)
|
Proxy
|
(outside-visible public IP/ports serving HTTPS/WSS)
|
Firewall
|
Internet


These instructions assume you run a server with Unix/Linux (very common if you use remote hosting) and that you have root access to that server.

The pieces we’ll need:

• HAProxy - an open-source proxy program that is easy to set up and use.

• LetsEncrypt for providing the User Certificate needed to establish an encrypted connection. In particular we’ll use the excellent Certbot program, which automates the whole certificate setup process with LetsEncrypt.

• cron - this comes with all Linux/Unix systems and allows to automate tasks in the OS.

Before starting you also need the following information and setup:

• (optional) The host name of your game. This is something you must previously have purchased from a domain registrar and set up with DNS to point to the IP of your server. For the benefit of this manual, we’ll assume your host name is my.awesomegame.com.

• If you don’t have a domain name or haven’t set it up yet, you must at least know the IP address of your server. Find this with ifconfig or similar from inside the server. If you use a hosting service like DigitalOcean you can also find the droplet’s IP address in the control panel. Use this as the host name everywhere.

• You must open port 80 in your firewall. This is used by Certbot below to auto-renew certificates. So you can’t really run another webserver alongside this setup without tweaking.

• You must open port 443 (HTTPS) in your firewall. This will be the external webserver port.

• Make sure port 4001 (internal webserver port) is not open in your firewall (it usually will be closed by default unless you explicitly opened it previously).

• Open port 4002 in firewall (we’ll use the same number for both internal- and external ports, the proxy will only show the safe one serving wss).

## Getting certificates¶

Certificates guarantee that you are you. Easiest is to get this with Letsencrypt and the Certbot program. Certbot has a lot of install instructions for various operating systems. Here’s for Debian/Ubuntu:

sudo apt install certbot


Make sure to stop Evennia and that no port-80 using service is running, then

sudo certbot certonly --standalone


You will get some questions you need to answer, such as an email to send certificate errors to and the host name (or IP, supposedly) to use with this certificate. After this, the certificates will end up in /etc/letsencrypt/live/<yourhostname>/*pem (example from Ubuntu). The critical files for our purposes are fullchain.pem and privkey.pem.

Certbot sets up a cron-job/systemd job to regularly renew the certificate. To check this works, try

sudo certbot renew --dry-run



The certificate is only valid for 3 months at a time, so make sure this test works (it requires port 80 to be open). Look up Certbot’s page for more help.

We are not quite done. HAProxy expects these two files to be one file. More specifically we are going to

1. copy privkey.pem and copy it to a new file named <yourhostname>.pem (like my.awesomegame.com.pem)

2. Append the contents of fullchain.pem to the end of this new file. No empty lines are needed.

We could do this by copy&pasting in a text editor, but here’s how to do it with shell commands (replace the example paths with your own):

cd /etc/letsencrypt/live/my.awesomegame.com/
sudo cp privkey.pem my.awesomegame.com.pem
sudo cat fullchain.pem >> my.awesomegame.com.pem


The new my.awesomegame.com.pem file (or whatever you named it) is what we will point to in the HAProxy config below.

There is a problem here though - Certbot will (re)generate fullchain.pem for us automatically a few days before before the 3-month certificate runs out. But HAProxy will not see this because it is looking at the combined file that will still have the old fullchain.pem appended to it.

We’ll set up an automated task to rebuild the .pem file regularly by using the cron program of Unix/Linux.

crontab -e


An editor will open to the crontab file. Add the following at the bottom (all on one line, and change the paths to your own!):

0 5 * * * cd /etc/letsencrypt/live/my.awesomegame.com/ &&
cp privkey.pem my.awesomegame.com.pem &&
cat fullchain.pem >> my.awesomegame.com.pem


Save and close the editor. Every night at 05:00 (5 AM), the my.awesomegame.com.pem will now be rebuilt for you. Since Certbot updates the fullchain.pem file a few days before the certificate runs out, this should be enough time to make sure HaProxy never sees an outdated certificate.

## Installing and configuring HAProxy¶

Installing HaProxy is usually as simple as:

# Debian derivatives (Ubuntu, Mint etc)
sudo apt install haproxy

# Redhat derivatives (dnf instead of yum for very recent Fedora distros)
sudo yum install haproxy


Configuration of HAProxy is done in a single file. This can be located wherever you like, for now put in your game dir and name it haproxy.cfg.

Here is an example tested on Centos7 and Ubuntu. Make sure to change the file to put in your own values.

We use the my.awesomegame.com example here and here are the ports

• 443 is the standard SSL port

• 4001 is the standard Evennia webserver port (firewall closed!)

• 4002 is the default Evennia websocket port (we use the same number for the outgoing wss port, so this should be open in firewall).

# base stuff to set up haproxy
global
log /dev/log local0
chroot /var/lib/haproxy
maxconn  4000
user  haproxy
tune.ssl.default-dh-param 2048
## uncomment this when everything works
# daemon
defaults
mode http
option forwardfor

# Evennia Specifics
listen evennia-https-website
bind my.awesomegame.com:443 ssl no-sslv3 no-tlsv10 crt /etc/letsencrypt/live/my.awesomegame.com>/my.awesomegame.com.pem
server localhost 127.0.0.1:4001
timeout client 10m
timeout server 10m
timeout connect 5m

listen evennia-secure-websocket
bind my.awesomegame.com:4002 ssl no-sslv3 no-tlsv10 crt /etc/letsencrypt/live/my.awesomegame.com/my.awesomegame.com.pem
server localhost 127.0.0.1:4002
timeout client 10m
timeout server 10m
timeout connect 5m


## Putting it all together¶

Get back to the Evennia game dir and edit mygame/server/conf/settings.py. Add:

WEBSERVER_INTERFACES = ['127.0.0.1']
WEBSOCKET_CLIENT_INTERFACE = '127.0.0.1'


and

WEBSOCKET_CLIENT_URL="wss://my.awesomegame.com:4002/"


Make sure to reboot (stop + start) evennia completely:

evennia reboot


Finally you start the proxy:

sudo haproxy -f /path/to/the/above/haproxy.cfg



Make sure you can connect to your game from your browser and that you end up with an https:// page and can use the websocket webclient.

Once everything works you may want to start the proxy automatically and in the background. Stop the proxy with Ctrl-C and make sure to uncomment the line # daemon in the config file.

If you have no other proxies running on your server, you can copy your haproxy.conf file to the system-wide settings:

sudo cp /path/to/the/above/haproxy.cfg /etc/haproxy/


The proxy will now start on reload and you can control it with

sudo service haproxy start|stop|restart|status


If you don’t want to copy stuff into /etc/ you can also run the haproxy purely out of your current location by running it with cron on server restart. Open the crontab again:

sudo crontab -e


Add a new line to the end of the file:

@reboot haproxy -f /path/to/the/above/haproxy.cfg


Save the file and haproxy should start up automatically when you reboot the server. Next just restart the proxy manually a last time - with daemon uncommented in the config file, it will now start as a background process.