Install systemd unit file if supported

[dleske]

Thank you for contributing to Harbor!

Comprehensive Summary of your change

On a systemd system, three or four of the necessary containers are started after a reboot of the 10 expected. Based on the advice in #18704, have added support for creating a systemd unit file in the install script. On a system without systemd, there is no effect.

Issue being fixed

Fixes #18704

Please indicate you've done the following:

• Well Written Title and Summary of the PR
• Label the PR as needed. "release-note/ignore-for-release, release-note/new-feature, release-note/update, release-note/enhancement, release-note/community, release-note/breaking-change, release-note/docs, release-note/infra, release-note/deprecation"
  • Did not see guidelines on labels in the contributing guide. I don't believe this change requires adding anything to the release notes. This may be worth noting as an enhancement.
• Accepted the DCO. Commits without the DCO will delay acceptance.
• Made sure tests are passing and test coverage is added if needed.
  • A cursory check through the tests directory indicates no tests make use of the install script.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed in website repository.
  • I do not believe the documentation would benefit from any addition here.

[codecov]

Codecov Report

Merging #19030 (9960f13) into main (db82d6e) will decrease coverage by 22.60%.
Report is 1 commits behind head on main.
The diff coverage is n/a.

@@             Coverage Diff             @@
##             main   #19030       +/-   ##
===========================================
- Coverage   67.43%   44.83%   -22.60%     
===========================================
  Files         992      244      -748     
  Lines      108727    13386    -95341     
  Branches     2747     2747               
===========================================
- Hits        73316     6002    -67314     
+ Misses      31479     7080    -24399     
+ Partials     3932      304     -3628     

Flag	Coverage Δ
unittests	44.83% <ø> (-22.60%)	⬇️

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see 754 files with indirect coverage changes

[wy65701436]

The installation script should not include the systemd service configuration. The purpose of the installation script is solely to handle the deployment of the Harbor service.

[dleske]

@wy65701436 I'm fine with the PR being rejected but the reasoning is unsound in my view. The install script's deployment is half-baked: it installs the service and starts it but does nothing to ensure it stays running. If I say I've deployed a service and it doesn't come back after a power outage or reboot, I haven't really deployed it.

Moreover, as the install script currently "deploys" the Harbor service, some of the containers are restarted on reboot, but fewer than half, leading to confusion and potentially a lack of trust in the software.

Finally, use of the unit file provided by Harbor is not documented as an installation step.