RemainAfterExit is needed about docker-systemctl-replacement HOT 2 CLOSED

From the systemd documentation:
https://www.freedesktop.org/software/systemd/man/systemd.service.html

RemainAfterExit=

• Takes a boolean value that specifies whether the service shall be considered active even when all its processes exited. Defaults to no.

Type=

• Behavior of oneshot is similar to simple; however, it is expected that the process has to exit before systemd starts follow-up units. RemainAfterExit= is particularly useful for this type of service. This is the implied default if neither Type= nor ExecStart= are specified.

Example 3

• For this, systemd knows the setting RemainAfterExit=yes, which causes systemd to consider the unit to be active if the start action exited successfully. This directive can be used with all types, but is most useful with Type=oneshot and Type=simple. With Type=oneshot, systemd waits until the start action has completed before it considers the unit to be active, so dependencies start only after the start action has succeeded. With Type=simple, dependencies will start immediately after the start action has been dispatched.

Example 4

• Many traditional daemons/services background (i.e. fork, daemonize) themselves when starting. Set Type=forking in the service's unit file to support this mode of operation. systemd will consider the service to be in the process of initialization while the original program is still running. Once it exits successfully and at least a process remains (and RemainAfterExit=no), the service is considered started.

from docker-systemctl-replacement.

The patches have solved the real case where it was used.

A testcase was written to confirm the result.

from docker-systemctl-replacement.