init-system-helpers binary package in Ubuntu Focal amd64

 This package contains helper tools that are necessary for switching between
 the various init systems that Debian contains (e. g. sysvinit or
 systemd). An example is deb-systemd-helper, a script that enables systemd unit
 files without depending on a running systemd.
 .
 It also includes the "service", "invoke-rc.d", and "update-rc.d" scripts which
 provide an abstraction for enabling, disabling, starting, and stopping
 services for all supported Debian init systems as specified by the policy.
 .
 While this package is maintained by pkg-systemd-maintainers, it is NOT
 specific to systemd at all. Maintainers of other init systems are welcome to
 include their helpers in this package.

Source package