The use of getopts was leading to conflicts between this script's short
options and qemu's long options. For example -serial was getting
interpreted as -s -- erial which is not very helpful.
If QEMU is given a uuid systemd will detect that and in turn use it for
the machine-id. This made the bug causing the machine-id to be always
re-generated on boot harder to notice since it didn't happen on QEMU.
Previously shifts were added into the getopts loop to work around
differences between different sh implementations but that causes getopts
to end the loop early. Instead use an intermediate variable to work
around inconsistent OPTIND behavior and explicitly check for the --
separator. Tested in bash, dash, and ash.
This one is more automagical and sets up ssh keys from ssh-agent and the
user's home directory by default. Also adds an option for setting the
ssh port so it can be something other than 2222. Script should be
sufficiently portable, tested in bash, dash, and ash.
