nixos: systemd user services

[offlinehacker]

So systemd supports user services, and some/most of nixos modules would not need a lot of changing to work in user environemnts(ex. changing the state dir). @zefhemel used supervisor for that(https://github.com/zefhemel/nix-docker), but that's not necessary and i would like to implement this, but first i would also like to get comments from others and especially @edolstra how to properly implement this.

[shlevy]

I have some ideas for how to do this properly (and they would even work on non-nixos systems that use systemd), but they will need to wait until #1021 is fixed as systemd has changed how user services work since our systemd version.

[shlevy]

Essentially we'd use the module system to define units and use that config to ultimately create a symlink tree that contains a bunch of unit files, plus an activation script to update relevant symlinks in the user's HOME and reload any needed targets, then have a simple tool like nixos-rebuild (that nixos-rebuild can hook into) to rebuild the tree + activation script and run the script.

[offlinehacker]

+1

[edolstra]

In the interim, you can use service-runner.nix, see 2b0aea1.

[offlinehacker]

@edolstra thanks, exactly what i needed for now :)

[offlinehacker]

We should have someting like system.defaultStateDir option(by default pointing to /var), which would be reused where needed. Then you could use it like dataDir = "${config.system.defaultStateDir}/db/postgresql". Do you see any problems with that and where should i put this option?

[offlinehacker]

I am now working on something similar now (https://github.com/offlinehacker/nix-services). I use supervisor for managing processes(basically expression from @zefhemel for nix-docker), because systemd does not work on darwin.

[shlevy]

Note also that @proger is working on an abstraction around services that might be useful here. Seems like a lot of people are converging on this problem :)

[offlinehacker]

I already have working implementation, which uses supervisord for running
services, i'm also using in production:
https://github.com/kiberpipa/nix-rehash/tree/master/nix-services
On Apr 5, 2014 7:23 PM, "Shea Levy" [email protected] wrote:

Note also that @proger https://github.com/proger is working on an
abstraction around services that might be useful here. Seems like a lot of
people are converging on this problem :)

Reply to this email directly or view it on GitHubhttps://github.com//issues/1689#issuecomment-39644844
.

[shlevy]

Ah cool, I just asked for that in another PR :) I think after 14.04 we should start coordinating and seeing if we can't converge on a solution.

[shlevy]

I no longer expect to have the bandwidth to take this on.

[domenkozar]

duplicate of #1689

[cstrahan]

@iElectric you closed this on the basis of it being a duplicate of #1689, but this is #1689. Did you have another issue in mind, or should this be reopened?

[wmertens]

@iElectric did you mean #4493 or #4594 or something else?

[domenkozar]

@wmertens correct, sorry for wrong info.