I've now found that the issue was that the service file automatically generated by systemd-sysv-generator lacks an install section with a WantedBy option. I added the following to my generated file at /etc/systemd/system/programexample.service which allowed me to properly enable the service:
[Install]
WantedBy = multi-user.target
After that I ran
systemctl daemon-reload
to ensure my service file was read by systemd.
Now I received a proper notification that my service was actually symlinked somewhere to be "enabled":
[root@centos7-box ~]# systemctl enable programexample.service
Created symlink from /etc/systemd/system/multi-user.target.wants/programexample.service to /etc/systemd/system/programexample.service.
This link helped me better understand the service file.
I am not a fan of the way that systemd-sysv-generator does not include an install section with a WantedBy option by default. If systemd can dynamically read the LSB headers and properly start services at boot, why doesn't it generate the service file accordingly? I suppose some systemd growing pains are to be expected.
Update July 7 2020:
Working with Debian Buster and trying to enable a SysVInit legacy service, I was presented with this wonderful message, which I believe would have saved me some time when I dealt with this issue in 2017:
Synchronizing state of programexample.service with SysV service script with
/lib/systemd/systemd-sysv-install.
Executing: /lib/systemd/systemd-sysv-install enable programexample
The unit files have no installation config (WantedBy=, RequiredBy=, Also=,
Alias= settings in the [Install] section, and DefaultInstance= for template units).
This means they are not meant to be enabled using systemctl.
Possible reasons for having this kind of units are:
• A unit may be statically enabled by being symlinked from another unit's
.wants/ or
.requires/ directory.
• A unit's purpose may be to act as a helper for some other unit which has
a requirement dependency on it.
• A unit may be started when needed via activation (socket, path, timer,
D-Bus, udev, scripted systemctl call, ...).
• In case of template units, the unit is meant to be enabled with some
instance name specified.
