HAProxy Config (Optional)

Making Evennia, HTTPS and Secure Websockets play nicely together

This we can do by installing a 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) - the proxy will transparently map that to the “real” outgoing ports and handle HTTPS/WSS for us.

Evennia <-> (inside-visible IP/ports) <-> Proxy <-> (outside-visible IP/ports) <-> Internet

Here we will use HAProxy, an open-source proxy that is easy to set up and use. We will also be using LetsEncrypt, especially the excellent helper-program Certbot which pretty much automates the whole certificate setup process for us.

Before starting you also need the following:

  • (optional) The host name of your game (like myawesomegame.com). 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.

  • If you don’t have a domain name or haven’t set it up yet, you must at least know the IP 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.

  • 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.

  • You must open port 4002 (the default Websocket port) in your firewall.

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/<your-host-or-ip>/*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.

sudo cp /etc/letsencrypt/live/<your-host-or-ip>/privkey.pem /etc/letsencrypt/live/<your-host-or-
ip>/<yourhostname>.pem
sudo bash -c "cat /etc/letsencrypt/live/<your-host-or-ip>/fullchain.pem >>
/etc/letsencrypt/live/<your-host-or-ip>/<yourhostname>.pem"

This will create a new .pem file by concatenating the two files together. The yourhostname.pem file (or whatever you named it) is what we will use when the the HAProxy config file (below) asks for “your-certificate.pem”.

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. Put this wherever you like, for example in your game dir; name it something like haproxy.conf.

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

# 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 <ip-address-or-hostname>:<public-SSL-port--probably-443> ssl no-sslv3 no-tlsv10 crt
/etc/letsencrypt/live/<your-host-or-ip>/<yourhostname>.pem
    server localhost 127.0.0.1:<evennia-web-port-probably-4001>
    timeout client 10m
    timeout server 10m
    timeout connect 5m

listen evennia-secure-websocket
    bind <ip-address-or-hostname>:<wss-port--probably-4002> ssl no-sslv3 no-tlsv10 crt
/etc/letsencrypt/live/<your-host-or-ip>/<yourhostname>.pem
    server localhost 127.0.0.1:<WEBSOCKET_CLIENT_PORT-probably-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://fullhost.domain.name:4002/"

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

evennia reboot

Finally you start the proxy:

sudo haproxy -f /path/to/the/above/config_file.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 uncomment the line # daemon in the config file, then start the proxy again

  • it will now start in the bacground.

You may also want to have the proxy start automatically; this you can do with cron, the inbuilt Linux mechanism for running things at specific times.

sudo crontab -e

Choose your editor and add a new line at the end of the crontab file that opens:

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

Save the file and haproxy should start up automatically when you reboot the server.