[🐛 Bug]: noVNC does not start due to malfunctioning -x check

[sergeygrigorev]

What happened?

noVNC does not start. Investigation showed that startup script fails on executable attribute check though it's set correctly.
The closest issue I managed to find is an old one in Alpine linux bug tracker. I think Ubuntu image might have something similar now.

Command used to start Selenium Grid with Docker (or Kubernetes)

version: '3'
services:
  selenium:
    image: selenium/standalone-chrome:4.25.0
    restart: unless-stopped
    shm_size: 2g
    ports:
      - "4444:4444"
      - "7900:7900"
    environment:
      - START_XVFB=true

Relevant log output

# docker logs <image-id>

WARN exited: novnc (exit status 1; not expected)

# docker exec -it <image-id> bash

seluser@host:/$ /opt/bin/start-novnc.sh
Trying to update the open file descriptor limit from 1048576 to 100000.
Successfully updated the open file descriptor limit.
Warning: could not find self.pem
The path /opt/bin/noVNC/utils/websockify exists, but /opt/bin/noVNC/utils/websockify/run either does not exist or is not executable.
If you intended to use an installed websockify package, please remove /opt/bin/noVNC/utils/websockify.

seluser@host:/$ ls -l /opt/bin/noVNC/utils/websockify/run
-rwxr-xr-x 1 root root 78 Aug 29 17:35 /opt/bin/noVNC/utils/websockify/run

seluser@host:/$ [ -x /opt/bin/noVNC/utils/websockify/run ]; echo $?
1

Operating System

Linux host 4.19.0-6-amd64 #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11) x86_64 x86_64 x86_64 GNU/Linux

Docker Selenium version (image tag)

4.25.0

Selenium Grid chart version (chart version)

No response

[github-actions]

@sergeygrigorev, thank you for creating this issue. We will troubleshoot it as soon as we can.

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Thank you!

[VietND96]

Hi, we are using the latest code frommain of novnc and websockify, properly directory structure updated or something else. I will look around for the fix.

[VietND96]

What is docker compose command that you used to start the container?
Here is my try

$ docker exec -it frosty_easley bash
To run a command as administrator (user "root"), use "sudo <command>".
See "man sudo_root" for details.

WARNING: Very high value reported by "ulimit -n". Consider passing "--ulimit nofile=32768" to "docker run".
seluser@780473f183d7:/$ /opt/bin/start-novnc.sh
Trying to update the open file descriptor limit from 1048576 to 100000.
Successfully updated the open file descriptor limit.
Port 7900 in use. Try --listen PORT
seluser@780473f183d7:/$ ls -l /opt/bin/noVNC/utils/websockify/run
-rwxr-xr-x 1 root root 78 Aug 29 14:35 /opt/bin/noVNC/utils/websockify/run

[sergeygrigorev]

docker-compose up -d --build --force-recreate
I also tried running it with docker run -d -p 4444:4444 -p 7900:7900 --shm-size="2g" selenium/standalone-chrome:latest as recommended on Docker Hub page. Same results.

[sergeygrigorev]

Tried fixing the issue.
Dockerfile:

FROM selenium/standalone-chrome:4.25.0
COPY ./novnc_proxy_updated /opt/bin/noVNC/utils/novnc_proxy

novnc_proxy_updated is a copy of original file with the failing -x check removed.

Running this:

# docker build .
# docker run -d --rm -p 4444:4444 -p 7900:7900 --shm-size="2g" <image-id>
# docker logs <container-id>
> WARN exited: novnc (exit status 1; not expected)
# docker exec -it <container-id> bash
# /opt/bin/start-novnc.sh

outputs this:

Trying to update the open file descriptor limit from 1048576 to 100000.
Successfully updated the open file descriptor limit.
Warning: could not find self.pem
Using local websockify at /opt/bin/noVNC/utils/websockify/run
realpath: /opt/bin/noVNC/utils/../: Operation not permitted
Starting webserver and WebSockets proxy on port 7900
/opt/bin/noVNC/utils/websockify/websockify/websocket.py:31: UserWarning: no 'numpy' module, HyBi protocol will be slower
  warnings.warn("no 'numpy' module, HyBi protocol will be slower")
Usage:
    __main__.py [options] [source_addr:]source_port target_addr:target_port
    __main__.py [options] --token-plugin=CLASS [source_addr:]source_port
    __main__.py [options] --unix-target=FILE [source_addr:]source_port
    __main__.py [options] [source_addr:]source_port -- WRAP_COMMAND_LINE

__main__.py: error: Too few arguments
Failed to start WebSockets proxy

[sergeygrigorev]

After fixing realpath: /opt/bin/noVNC/utils/../: Operation not permitted by making start-novnc.sh provide --web /opt/bin/noVNC to novnc_proxy script, noVNC starts successfully but shows wallpaper error:

fbsetbg: /usr/share/images/fluxbox/ubuntu-light.png isn't an existing wallpaper or a valid option.