How to host websocket behind nginx reverse proxy - docker

Question

On my VPS I only have one port and this is the reason why I use proxer - a dockerized nginx reverse proxy where you provide domain names and local ports to which it should be redirected.
I have successfully set up socket.io server with polling transport (as it uses http methods) but I would like to use websocket transport and this is where it fails. It tells me it can't estabilish wss:// connection to this url.
This is nginx reverse proxy code I am using:
for cfg in $(cat /config); do
domain=$(echo $cfg | cut -f1 -d=)
destination=$(echo $cfg | cut -f2 -d=)
echo ">> Building config for $domain";
config=$(cat <<EOF
server {
listen 80;
listen [::]:80;
server_name $domain;
location / {
proxy_pass $destination;
proxy_set_header Host \$host;
proxy_http_version 1.1;
proxy_set_header Upgrade \$http_upgrade;
#proxy_set_header Connection \$connection_upgrade;
proxy_ssl_name \$host;
proxy_ssl_server_name on;
proxy_ssl_verify off;
proxy_ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
proxy_ssl_session_reuse off;
proxy_set_header X-Forwarded-For \$remote_addr;
proxy_set_header X-Forwarded-Proto \$scheme;
proxy_read_timeout 120;
proxy_send_timeout 120;
proxy_connect_timeout 120;
}
}
EOF
)
# append new config to the end of nginx config file
echo "$config" >>$out
done
I noticed that this line is commented out and I read that it is needed for wss://:
#proxy_set_header Connection \$connection_upgrade;
Why is it commented out?
Will changing this line affect http proxy?
What changes should I do to allow wss:// on one of domains

Answer 1

This tool has pretty much everything what is needed to set up nginx reverse proxy.
Note that it won't support wss:// out of the box though due to this commented line in its config.
#proxy_set_header Connection \$connection_upgrade;
Uncomment it, rebuild and have a happy reverse proxy which supports wss:// :)