Spring WebSocket: Handshake failed due to invalid Upgrade header: null

I met the same problem with nginx https proxy to tomcat. This is because I haven't support the wss request. To support the wss request, I use the config like below:

# WebSocketSecure SSL Endpoint## The proxy is also an SSL endpoint for WSS and HTTPS connections.# So the clients can use wss:// connections # (e.g. from pages served via HTTPS) which work better with broken # proxy servers, etc.server {    listen 443;    # host name to respond to    server_name ws.example.com;    # your SSL configuration    ssl on;    ssl_certificate /etc/ssl/localcerts/ws.example.com.bundle.crt;    ssl_certificate_key /etc/ssl/localcerts/ws.example.com.key;    location / {        # switch off logging        access_log off;        # redirect all HTTP traffic to localhost:8080        proxy_pass http://localhost:8080;        proxy_set_header X-Real-IP $remote_addr;        proxy_set_header Host $host;        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;        # WebSocket support (nginx 1.4)        proxy_http_version 1.1;        proxy_set_header Upgrade $http_upgrade;        proxy_set_header Connection "upgrade";    }}

the following solution works for me

<VirtualHost _default_:443>        ServerName my.app    ServerAdmin admin@my.app    DocumentRoot /var/www/html    SSLCertificateFile ...    SSLCertificateKeyFile ...    SSLCertificateChainFile ...        ProxyPreserveHost on    RequestHeader set X-Forwarded-Proto https    RequestHeader set X-Forwarded-Port 443        RewriteEngine on    RewriteCond %{HTTP:Upgrade}^websocket$ [NC,OR]    RewriteCond %{HTTP:Connection}^upgrade$ [NC]    RewriteRule .* wss:/127.0.0.1:8081%{REQUEST_URI} [P,QSA,L]    RewriteCond %{REQUEST_URI} ^/api/wsendpoint/%{var1}/%{var2}/websocket [NC,OR]    ....    </VirtualHost>

I hope, that helps...The solution above is part of the following link:https://forum.mattermost.org/t/solved-apache2-reverseproxy-with-websocket-https/437/3

this post seems closed, but I don't found an exact solution here so I will post for future needes

I resolved with reverse proxy configuration (in my case apache httpd)

at first you have to enable some mods in httpd.conf

LoadModule proxy_wstunnel_module modules/mod_proxy_wstunnel.soLoadModule proxy_module modules/mod_proxy.soLoadModule rewrite_module modules/mod_rewrite.so

then go into your virtual host configuration and use this rules

RewriteCond %{HTTP:Upgrade} websocket [NC]RewriteCond %{HTTP:Connection} upgrade [NC]RewriteRule /(.*) "ws://[YOUR_URL]:[YOUR_PORT]/$1" [P,L]

obviously substitute [YOUR_URL] and [YOUT_PORT] with real url and port, and substitute "ws" with "wss" if you are using secure web socket

that's all!

if you have done the right things in your server you can read the following headers

upgrade: WebSocketconnection: Upgrade