Feature parity with nixos-rebuild

[viperML]

If we strive for mass adoption of nh, feature parity is something to consider

• nixos-rebuild
  • switch
  • boot
  • test
  • build
  • dry-build
  • dry-activate
  • edit
  • build-vm (Add build-vm subcommand to nh os build to build a VM start script. #208)
  • build-vm-with-bootloader (Add build-vm subcommand to nh os build to build a VM start script. #208)
  • --upgrade (flakes)
  • --upgrade (channels)
  • --install-bootloader
  • --no-build-nix, --fast (only this is supported)
  • --rollback nixos: implement rollbacks #265
  • --builders (via passthrough of options)
  • --profile-name
  • --build-host, --target-host nixos: add --target-host and --build-host options #276
    • --use-substitutes, --use-remote-sudo (nh as a deployment tool)
  • --flake
  • -I nixos-config=...

[NotAShelf]

I'll take a look at rollback tonight.

[cramt]

having the --target-host option would be really awesome, i might look into implementing when i have some time

[cdo256]

Note that we already have --dry which covers dry-build, and from looking at the source of nixos-rebuild, it seems that dry-activate does pretty much the same thing as build, so I can't really see a use case for it.
edit just looks up NIX_CONFIG (failing that does a search in your NIX_PATH for nixos-config) and opens ./default.nix in that directory. I don't think very many people have a ./default.nix in their NixOS config, so this command seems broken by design, and I vote we don't bother including it.
build-vm and build-vm-with-bootloader are in pull 208, and should be nearly ready to merge.

--install-bootloader apparently reinstalls the bootloader and can be achieved by simly setting NIXOS_INSTALL_BOOTLOADER=1 before running switch-to-configuraiton, so that's an easy one.
--no-build-nix, --fast both stop nix being updated and nixos-rebuild being run a second time. That's not done in nh to my knowledge, so these aren't neccessary.
--rollback has been merged.

There's a few more passthrough args: (from nixos-rebuild.sh). Should be fairly low-hanging.

      -I|--builders)
        j="$1"; shift 1
        extraBuildFlags+=("$i" "$j")
        ;;
      --max-jobs|-j|--cores|--log-format)
        j="$1"; shift 1
        extraBuildFlags+=("$i" "$j")
        copyFlags+=("$i" "$j")
        ;;
      --accept-flake-config|-j*|--quiet|--print-build-logs|-L|--no-build-output|-Q|--show-trace|--refresh|--impure|--offline|--no-net)
        extraBuildFlags+=("$i")
        ;;
      --keep-going|-k|--keep-failed|-K|--fallback|--repair)
        extraBuildFlags+=("$i")
        copyFlags+=("$i")
        ;;
      --verbose|-v|-vv|-vvv|-vvvv|-vvvvv)
        verboseScript="true"
        extraBuildFlags+=("$i")
        copyFlags+=("$i")
        ;;
      --option)
        j="$1"; shift 1
        k="$1"; shift 1
        extraBuildFlags+=("$i" "$j" "$k")
        copyFlags+=("$i" "$j" "$k")
        ;;

--profile-name can be parameterized, it has needs to be propagated to work with rollback and info, but shouldn't be too hard.

The remote deployment I have no idea about, at a guess probably the most work of those yet to be done.

-I - isn't this just the number of builders?

[NotAShelf]

for nh {os,home,darwin} edit I was thinking $EDITOR $NH_FLAKE and not much else. Open to debate whether this is worth the... 5 lines of code to handle it.

[viperML]

That could suport easily -f as an installable, and for --expr just bail out.

[NotAShelf]

I really don't want to think about non-flake setups, to be perfectly honest. I don't use non-flakes and over 80% of our users use flakes. Though I think the code will be mildly easier to manage after #281, hopefully.

[kalyanoliveira]

Any comments on future support for --file?

[viperML]

NH has supported --file since v4

[Henry-Hiles]

Remote sudo isn't working for me, I get this: sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper

[cdo256]

Remote sudo isn't working for me, I get this: sudo: a terminal is required to read the password; either use the -S option to read from standard input or configure an askpass helper

Please could you raise a PR please with the command you're running, the environment you're running in and the messages printed when running when -v --no-nom is appended to your command.

[cdo256]

I've made a PR adding rebuild passthrough arguments: #311

I've included all of them there that seemed relevant, but we probably don't want to support all of them, so leave feedback on that PR as to what you think could be dropped.