Support updating existing installation?

[botandrose]

Hi @vifreefly , I've added experimental user-mode support on my own branch and I'm testing it out for a while before contributing it back.

One thing I've noticed that surprised me: procsd doesn't seem to support deploying changes to an existing procsd.yml file. In lib/procsd/cli.rb I see commands for create and destroy, but not update. Is this intentional?

Would you be willing to merge in a PR that adds this update functionality in some way?

[vifreefly]

Hey @botandrose , yes update command not supported yet, now you have to do procsd destroy and then procsd create in order to update. Some discussion about that here #1 (comment) .

Update command is useful, but at the moment of creation of this tool it was fine for me just to use procsd destroy && then procsd create.

Would you be willing to merge in a PR that adds this update functionality in some way?

sure

[botandrose]

@vifreefly Okay, great! I liked everything you said in your comment there, so I'll use that as a guide for preparing the update command PR.

The one place where I have different thoughts is that I don't believe we'll need a .lock file of any kind. I think when the update command runs on the server, it can inspect the current systemd tree, and compare that to the procsd.yml file, and use that to perform the "diff", no lockfile needed. I have a prototype of this working already, but maybe it has issues I'm not seeing.

Anyways, I'm glad that you're still accepting contributions to this gem! Thank you for your time!

Once the modernize PR is merged, I'll push a few more testing PRs, and then move onto adding the update command and user mode.

[vifreefly]

@botandrose thanks for your PRs, they were merged https://github.com/vifreefly/procsd/blob/master/CHANGELOG.md#060 and new version of gem 0.6.0 was released. I did some testing and everything seems to work fine, thanks to systemd API which stays the same over the years.

The one place where I have different thoughts is that I don't believe we'll need a .lock file of any kind. I think when the update command runs on the server, it can inspect the current systemd tree, and compare that to the procsd.yml file, and use that to perform the "diff", no lockfile needed. I have a prototype of this working already, but maybe it has issues I'm not seeing.

sounds good to me 👍