Subdirectory doesn't work for socket.io path

[demyxco]

Issue details

I have BrowserSync as a Docker container on a remote server with Traefik as the reverse proxy, it works well with HTTPS and using subdomains. I want to move the access URL and UI to a subdomain to reduce SSL cert requests to LetsEncrypt but I am having some trouble. I've tried everything from changing the socket's namespace, domain, path, and clientPath. It either 502s or 404s, even tried some NGINX magic, but still no dice. The setup I had plan for was this:

• Target => http://domain.tld (WordPress)
• Proxy => http://domain.tld
• Traefik host rule => http://domain.tld/demyx-bs/

Steps to reproduce/test case

I'm not sure how others environments are setup but you can just simply try changing the socket.io path and see if you can have it configured on a subdirectory (domain.tld/sub/browser-sync/socket.io).

Please specify which version of Browsersync, node and npm you're running

• Browsersync [ 2.26.7 ]
• Node [ v12.4.0 ]
• Npm [ 6.9.0 ]

Affected platforms

• [✅] linux
• windows
• OS X
• freebsd
• solaris
• other (please specify which)

Browsersync use-case

• [✅] API
• Gulp
• Grunt
• [✅] CLI

If CLI, please paste the entire command below

docker run -d --rm \
--name "$DEMYX_APP_COMPOSE_PROJECT"_bs \
--net demyx \
--volumes-from "$DEMYX_APP_WP_CONTAINER" \
-l "traefik.enable=true" \
-l "traefik.bs.frontend.rule=Host:${DEMYX_APP_DOMAIN}; PathPrefixStrip: /demyx-bs/" \
-l "traefik.bs.port=3000" \
-l "traefik.ui.frontend.rule=Host:${DEMYX_APP_DOMAIN}; PathPrefixStrip: /demyx-ui/" \
-l "traefik.ui.port=3001" \
demyx/browsersync start \
--config "/demyx/bs.js" \
--proxy "$DEMYX_APP_WP_CONTAINER" \
--files "/var/www/html/**/*" \
--port 3000 \
--ui-port 3001 

for all other use-cases, (gulp, grunt etc), please show us exactly how you're using Browsersync

bs.js

module.exports={ 
    script: { 
        domain: '/demyx-bs' 
    }, 
    socket: { 
        domain: '/demyx-bs', 
        path: '/demyx-bs/browser-sync/socket.io', 
        clientPath: '/demyx-bs/browser-sync', 
        namespace: '/demyx-bs/browser-sync' 
    } 
};

nginx.conf

upstream bs {
    server 127.0.0.1:3000;
}

location /demyx-bs/browser-sync/socket.io/ {
    proxy_pass http://bs/demyx-bs/;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection "Upgrade";
}

[demyxco]

I managed to solve this, so I'm closing the issue. It was NGINX that saved the day:

location /browser-sync/socket.io/ {
    proxy_pass http://browsersync_container:3000/browser-sync/socket.io/;
    proxy_http_version 1.1;
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection 'upgrade';
    proxy_set_header Host $host;
    proxy_cache_bypass $http_upgrade;
}