/usr/local/lib/ruby/3.1.0/securerandom.rb:75:in `urandom': failed to get urandom (RuntimeError)

[darksidds]

I'm working with redmine image, which is based on ruby image.
I've posted my problem here docker-library/redmine#264
The image is based on FROM ruby:3.1-slim-bullseye, so I've tried to run pure ruby image.
The steps to reproduce my problem:

# docker run -it --rm ruby:3.1-bullseye bash
root@c39956abcf4e:/# irb
irb(main):001:0> require 'securerandom'
/usr/local/lib/ruby/3.1.0/securerandom.rb:75:in `urandom': failed to get urandom (RuntimeError)
        from /usr/local/lib/ruby/3.1.0/securerandom.rb:75:in `singleton class'
        from /usr/local/lib/ruby/3.1.0/securerandom.rb:42:in `<module:SecureRandom>'
        from /usr/local/lib/ruby/3.1.0/securerandom.rb:41:in `<top (required)>'
        from <internal:/usr/local/lib/ruby/3.1.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
        from <internal:/usr/local/lib/ruby/3.1.0/rubygems/core_ext/kernel_require.rb>:85:in `require'
        from (irb):1:in `<main>'
        from /usr/local/lib/ruby/gems/3.1.0/gems/irb-1.4.1/exe/irb:11:in `<top (required)>'
        from /usr/local/bin/irb:25:in `load'
        from /usr/local/bin/irb:25:in `<main>'

I've also tried images ruby:3.2-rc-slim and ruby:3.0-slim-bullseye -- they work OK!
But all flavours of 3.1-* seem to be broken.
My host machine is

# lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 10 (buster)
Release:        10
Codename:       buster
# uname -r
3.16.0-4-amd64
# cat /proc/version
Linux version 3.16.0-4-amd64 (debian-kernel@lists.debian.org) (gcc version 4.8.4 (Debian 4.8.4-1) ) #1 SMP Debian 3.16.43-2+deb8u5 (2017-09-19)

[tianon]

😬 I can't seem to reproduce:

$ docker run -it --rm --pull=always ruby:3.1-slim-bullseye
3.1-slim-bullseye: Pulling from library/ruby
214ca5fb9032: Already exists 
78121ab1df60: Pull complete 
48fbe7e8745f: Pull complete 
6edc84d3fe34: Pull complete 
2152ead824bc: Pull complete 
Digest: sha256:45bf81172fb1169d5659254601c9608704337592e73b5c3e5bee436deb695f2a
Status: Downloaded newer image for ruby:3.1-slim-bullseye
irb(main):001:0> require 'securerandom'
=> true

[yosifkit]

👀 I would hazard a guess that it might have something to do with running on a 3.16 kernel or likely an old version of libseccomp or Docker. I am not sure how the kernel isn't newer, since 4.19 is the kernel in buster (https://packages.debian.org/buster/linux-image-amd64)

A newer version of Docker, runc, and/or libseccomp might fix this one, but it could also need a kernel bump.

Similar issues: #351 docker-library/php#1192 docker-library/php#1177

[darksidds]

I had an extremely old kernel, so I decided to switch OS on the host machine. The problem is not relevant to me any longer.
Thanks for your help!