Hi, On 30/03/15 14:45, Christian Theune wrote:
> last year I experimented with self-managing NixOS installations. One thing > that I stumbled upon was that regularly triggering nixos-rebuild would create > new generations even though the config hadn’t changed. > > Is there a way to suppress that or a reason why this can’t be suppressed in > general? The reason is to ensure that "nixos-rebuild switch; nixos-rebuild rollback" always rolls back to the configuration just before the switch, not to some earlier configuration. If "nixos-rebuild switch" is a logical no-op, then the rollback should do nothing, too. Note that generations are cheap (they're just symlinks), but we should probably filter redundant generations from the GRUB boot menu. > What I want is to create a simple cronjob that generates Nix OS configuration > from an upstream “source of truth”, like users, and not think about > convergence but just trigger nixos-rebuild after updating the config. If > nothing changed then no new generation should appear IMHO. We could add an option to suppress creating a new generation if nothing has changed. -- Eelco Dolstra | LogicBlox, Inc. | http://nixos.org/~eelco/ _______________________________________________ nix-dev mailing list nix-dev@lists.science.uu.nl http://lists.science.uu.nl/mailman/listinfo/nix-dev
