Starting tabbyml behind nginx reverse proxy requires websocket support

[oli-ver]

Describe the bug
Running any prompts in the chatbox on the web page of Tabby or in the VSCode plugin result in the following error message:

{
  "error": true,
  "message": "[Network] undefined"
}

Information about your version
Please provide output of tabby --version

./tabby --version
tabby 0.18.0

Information about your GPU
Please provide output of nvidia-smi

Only CPU mode (linux virtual server)

Additional context
Add any other context about the problem here.

Running tabby natively or in Docker on Debian GNU/Linux 11 (bullseye). No GPU available on the system.

Installation steps native:

useradd -m -s /usr/bin/zsh tabby
su - tabby
wget https://github.com/TabbyML/tabby/releases/download/v0.18.0/tabby_x86_64-manylinux2014.zip
unzip tabby_x86_64-manylinux2014.zip
mv dist/* ~
chmod +x tabby llama-server
TABBY_WEBSERVER_JWT_TOKEN_SECRET=mysecret ./tabby serve --model StarCoder-1B --chat-model Qwen2-1.5B-Instruct --port 8090 --host 127.0.0.1 --device cpu

Installation steps docker:

services:
  tabby:
    restart: always
    image: registry.tabbyml.com/tabbyml/tabby
    environment:
     - ENDPOINT=https://my-endpoint.com
     - TABBY_WEBSERVER_JWT_TOKEN_SECRET=mysecret
     - LD_LIBRARY_PATH=/usr/local/cuda/lib64:/usr/local/cuda/compat:$ #workaround cuda errors, see https://github.com/TabbyML/tabby/issues/2634#issuecomment-2244530283
    entrypoint: /opt/tabby/bin/tabby-cpu
    command: serve --device cpu --model StarCoder-1B --chat-model Qwen2-1.5B-Instruct
    volumes:
      - "./data:/data"
    ports:
      - 127.0.0.1:8090:8080

The only configuration I made was to create a first admin and configure the endpoint URL of my server. I am running zabby behind a nginx reverse proxy with SSL configuration. Both setups natively or in docker result in the same error.

While writing this bug report I found the resolution as well. I tried to run tabby without reverse proxy and it worked. It seemed to be related to my nginx reverse proxy configuration. Initially it was:

        location / {
            proxy_pass       http://localhost:8090;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
        }

Following the instructions found here I changed it to:

        location / {
            proxy_pass       http://localhost:8090;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection "upgrade";
        }

With this configuration it works.

Sharing this experience now more for other users experiencing the same problem.

I will create a pull request for an documentation update both for running behind reverse proxy and how to run in docker without GPU.