basic nix support, builds subkey and provides it to other packages

[dzmitry-lahoda]

Basic nix support.

• What does it do?

Builds subkey via nix

• What important points should reviewers know?

nix run .#subkey, ensure flakes enabled (zero to nix installer is default)

Is there something left for follow-up PRs?
no follow up, so may build other tools if there are later

other usage of nix can be seen here https://github.com/paritytech/zombienet for example

[ggwpez]

Nix usage in the past had the problem that is was got out-dated since there was no CI to check that it still builds.
Maybe a good follow-up would be to add that.

[dzmitry-lahoda]

@ggwpez as soon as repo will get rust-toolchain.toml will do:

rust-toolchain =
            pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml; # by the way, i bet parity breaks people and CI often because toolchain and its components are not in repo

to upgrade cpp deps (clang/protoc/openssl):

nix flake update

any nix run github:paritytech/substrate#subkey or deps via overlays will break as soon as it is outdated, sure I am adding one right now into one chain repo :) so it will be fixed, and that is IF. likely it will not.

likely you used nix before flake, and may be 3 years ago right? that is different these days. and really people use paritytech/substrate/<commit>#subkey inside their flakes, so they will not break as soon as they have it frozen for a while.

and likely subkey will not change its name. and hope will not start doing things like running wasm lightclient with network access:)

also as in PR - gitignore reused.

[dzmitry-lahoda]

@ggwpez

I use this in some random project CI. CI will break here.

i doubt modifying parity CI is possible goal now (that needs alignment from parity to them create cachix, etc)

but here it is

env:
  NIX_VERSION: nix-2.13.2
  NIXPKGS_CHANNEL: nixos-22.11
  CACHIX_NAME: paritytech

jobs:
  build-nix:
    name: "build-nix"
    runs-on:
      - ubuntu-latest
    concurrency:
      group: build-nix-${{ github.ref }}
      cancel-in-progress: true
    steps:
      - name: cachix-install-nix-action
        uses: cachix/install-nix-action@be4cef7b776998e97233d6e0b84c538eb8122d76
        with:
          install_url: https://releases.nixos.org/nix/${{ env.NIX_VERSION }}/install
          nix_path: nixpkgs=channel:${{ env.NIXPKGS_CHANNEL }}
          extra_nix_config: |
            sandbox = relaxed
            narinfo-cache-negative-ttl = 0      
            system-features = kvm
            http2 = true
      - name: cachix-cachix-action
        uses: cachix/cachix-action@298387a7aea14d6564aa5d6ead79272878339c8b
        with:
          authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
          name: ${{ env.CACHIX_NAME }}
      - name: nix-channel-env
        run: |  
          nix-channel --add https://nixos.org/channels/${{ env.NIXPKGS_CHANNEL }} nixpkgs
          nix-channel --update
          nix profile install nixpkgs#git
      - uses: actions/checkout@v3
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          persist-credentials: false
      - run: |          
          mkdir out
          nix build .#subkey --print-build-logs --show-trace --no-update-lock-file

also flakes allow to fully evaluate but not build to avoid nix rot, but that is for huge repos. so nix breaks much less these days.

[dzmitry-lahoda]

@ggwpez

Follow up likely would be replace in chains which nix substrate/polkadot/cumulus stuff to reuse env/lib/rust setup (hence adding something like pkgs.subnix overlay with it. Long term followup are zombienet networks nixified (sure polkadot/cumulus nodes to be nixified too - already in composable - just no PRed), but that is not where I need solutions now. Really need more smoldot.

[dzmitry-lahoda]

@ggwpez i am not agains CI PR sure, but that could be out of scope for Parity to merge it now? so nixified subkey tool is nice regardless imho. you can onliner it it on nixos ;)

[ggwpez]

@ggwpez i am not agains CI PR sure, but that could be out of scope for Parity to merge it now? so nixified subkey tool is nice regardless imho. you can onliner it it on nixos ;)

Yes sure it is out of scope.

I personally dont use nix/flake, so cant approve. But maybe @bkchr can 😄

[dzmitry-lahoda]

oh, there was some #13706 . imho nix should be in root to cover tools too ;)

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.

[dzmitry-lahoda]

I will fix it once per comments. Hope Parity will be able to review this time to 2 core devs (I start feeling bearish :( btw, not only this PR but some awesome otherrs ) . Cosmos and Ethereum already awesomly nixified. So unlike them, Substrate is of too high ABI/API fidelity, so cannot make it in outer repo without being all the time broken.

[andresilva]

Thanks for the PR and really sorry for this not getting merged sooner. I started making some suggestions but they became too much to add here, so here's a commit with all my proposed changes: b8c4f7c. Some are just style nits, but some other changes make the definition simpler (like using bindgenHook instead of manually setting up clang), feel free to include whatever you think makes sense.

[andresilva]

stable works as well, and we could even use the rust toolchain from nixpkgs directly (that's what I use to build subkey on my computer).

[andresilva]

@dzmitry-lahoda could you fix the conflicts so that this can be merged? I can't push to your branch.

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.