ops/machines.nix

# Top-level file aggregating all machines managed from hscloud.
#
# This allows to have a common attrset of machines that can be deployed
# in the same way.
#
# For information about building/deploying machines see //ops/README.md.

{ hscloud, pkgs, ... }:

let
  # nixpkgs for cluster machines (.hswaw.net). Currently pinned to an old
  # nixpkgs because NixOS modules for kubernetes changed enough that it's not
  # super easy to use them as is.
  #
  # TODO(q3k): fix this: use an old nixpkgs for Kube modules while using
  # hscloud nixpkgs for everything else.
  nixpkgsCluster = import (pkgs.fetchFromGitHub {
    owner = "nixos";
    repo = "nixpkgs-channels";
    rev = "44ad80ab1036c5cc83ada4bfa451dac9939f2a10";
    sha256 = "1b61nzvy0d46cspy07szkc0rggacxiqg9v1py27pkqpj7rvawfsk";
  }) {
    overlays = [
      (self: super: rec {
        # Use a newer version of Ceph (16, Pacific, EOL 2023-06-01) than in
        # this nixpkgs (15, Octopus, EOL 2022-06-01).
        #
        # This is to:
        #  1. Fix a bug in which ceph-volume lvm create fails due to a rocksdb
        #     mismatch (https://tracker.ceph.com/issues/49815)
        #  2. At the time of deployment not start out with an ancient version
        #     of Ceph.
        #
        # Once we unpin nixpkgsCluster past a version that contains this Ceph,
        # this can be unoverlayed.
        inherit (super.callPackages ./ceph {
          boost = super.boost17x.override { enablePython = true; python = super.python3; };
          lua = super.lua5_4;
        }) ceph ceph-client;
        ceph-lib = ceph.lib;
      })
    ];
  };

  # edge01 still lives on an old nixpkgs checkout.
  #
  # TODO(b/3): unpin and deploy.
  nixpkgsBgpwtf = import (pkgs.fetchFromGitHub {
    owner = "nixos";
    repo = "nixpkgs-channels";
    rev = "c59ea8b8a0e7f927e7291c14ea6cd1bd3a16ff38";
    sha256 = "1ak7jqx94fjhc68xh1lh35kh3w3ndbadprrb762qgvcfb8351x8v";
  }) {};

  # Stopgap measure to import //cluster/nix machine definitions into new
  # //ops/ infrastructure.
  #
  # TODO(q3k): inject defs-cluster-k0.nix / defs-machines.nix content via
  # nixos options instead of having module definitions loading it themselves,
  # deduplicate list of machines below with defs-machines.nix somehow.
  clusterMachineConfig = name: [({ config, pkgs, ...}: {
    # The hostname is used by //cluster/nix machinery to load the appropriate
    # config from defs-machines into defs-cluster-k0.
    networking.hostName = name;
    imports = [
      ../cluster/nix/modules/base.nix
      ../cluster/nix/modules/kubernetes.nix
      ../cluster/nix/modules/ceph.nix
    ];
  })];

  # mkMachine builds NixOS modules into a NixOS derivation.
  # It:
  #  1) injects passthru.hscloud.provision which deploys that configuration
  #     over SSH to a production machine.
  #  2) injects 'workspace' as a nixos module argument which points to the root
  #     of the hscloud readTree object. It will contain whatever nixpkgs
  #     checkout this file has been invoked with, ie. will not be 'mixed in'
  #     with the pkgs argument.
  mkMachine = pkgs: paths: pkgs.nixos ({ config, pkgs, ... }: {
    imports = paths;

    config = let
      name = config.networking.hostName;
      domain = if (config.networking ? domain) && config.networking.domain != null then config.networking.domain else "hswaw.net";
      fqdn = name + "." + domain;
      toplevel = config.system.build.toplevel;

      runProvision = ''
        #!/bin/sh
        set -eu
        remote=root@${fqdn}
        echo "Configuration for ${fqdn} is ${toplevel}"
        nix copy -s --to ssh://$remote ${toplevel}

        running="$(ssh $remote readlink -f /nix/var/nix/profiles/system)"
        if [ "$running" == "${toplevel}" ]; then
          echo "${fqdn} already running ${toplevel}."
        else
          echo "/etc/systemd/system diff:"
          ssh $remote diff -ur /var/run/current-system/etc/systemd/system ${toplevel}/etc/systemd/system || true
          echo ""
          echo ""
          echo "dry-activate diff:"
          ssh $remote ${toplevel}/bin/switch-to-configuration dry-activate
          read -p "Do you want to switch to this configuration? " -n 1 -r
          echo
          if ! [[ $REPLY =~ ^[Yy]$ ]]; then
            exit 1
          fi

          echo -ne "\n\nswitch-to-configuration test...\n"
          ssh $remote ${toplevel}/bin/switch-to-configuration test
        fi

        echo -ne "\n\n"
        read -p "Do you want to set this configuration as boot? " -n 1 -r
        echo
        if ! [[ $REPLY =~ ^[Yy]$ ]]; then
            exit 1
        fi

        echo -ne "\n\nsetting system profile...\n"
        ssh $remote nix-env -p /nix/var/nix/profiles/system --set ${toplevel}

        echo -ne "\n\nswitch-to-configuration boot...\n"
        ssh $remote ${toplevel}/bin/switch-to-configuration boot
      '';
    in {
      passthru.hscloud.provision = pkgs.writeScript "provision-${fqdn}" runProvision;

      # TODO(q3k): this should be named hscloud, but that seems to not work. Debug and rename.
      _module.args.workspace = hscloud;
    };
  });
in {
  "bc01n01.hswaw.net"  = mkMachine nixpkgsCluster (clusterMachineConfig "bc01n01");
  "bc01n02.hswaw.net"  = mkMachine nixpkgsCluster (clusterMachineConfig "bc01n02");
  "dcr01s22.hswaw.net" = mkMachine nixpkgsCluster (clusterMachineConfig "dcr01s22");
  "dcr01s24.hswaw.net" = mkMachine nixpkgsCluster (clusterMachineConfig "dcr01s24");

  "edge01.waw.bgp.wtf" = mkMachine nixpkgsBgpwtf [
    ../bgpwtf/machines/edge01.waw.bgp.wtf.nix
    ../bgpwtf/machines/edge01.waw.bgp.wtf-hardware.nix
  ];
}