Binding of "0.0.0.0" for etherpad container leads to health-check issues with docker 25.0.5

[ichdasich]

The etherpad container binds etherpad to 0.0.0.0. The health-check included tries to query the health state of etherpad vial 'localhost'; However, with docker 25.0.5 some IPv6 related defaults changed. This means that localhost now first resolves to ::1 and the health-check fails, leading to a restart loop for the container if corresponding monitoring/enforcement is enabled.

Options are:

• Bind etherpad to a v4/v6 socket globally ([::])
• Force the health-check to use 127.0.0.1
• Remove ::1 localhost from /etc/hosts
• Disable ipv6 for the specific container:

    sysctls:
      net.ipv6.conf.all.disable_ipv6: '1'

However, the latter hard-requires using a more recent docker-compose (does not work with 1.29.2, works with v2.25.0).

[yanus]

This seems to be an issue with the Etherpad image, rather than BigBlueButton, and has been fixed in version 2 by using curl for the health check: https://github.com/ether/etherpad-lite/blob/fb56809e5565aca22e279e4413652d2ecfd0acaf/Dockerfile#L151-L152

While upgrading Etherpad is probably not recommended (due to compatibility with BBB), just copying the health check from the new version seems to fix the problem.