nixos-config/lib/morph.nix
2021-12-21 10:06:06 -05:00

115 lines
3.8 KiB
Nix

{ self
, extraMorphModules ? [ ]
}:
# to use this library, add the following to "morph.nix" in your repo:
# (builtins.getFlake (toString ./.)).morph-entrypoint builtins.currentSystem
let
inherit (self.inputs) nixpkgs;
inherit (self) nixosConfigurations;
helpers = system:
let
pkgs = nixpkgs.legacyPackages.${system};
inherit (nixpkgs.lib) concatMapStrings;
sshKnownHostsTxt = pkgs.writeText "known_hosts" (concatMapStrings
(hostName:
let m = nixosConfigurations.${hostName}.config.sconfig.morph;
in concatMapStrings (key: "${m.deployment.targetHost} ${key}\n") m.sshPublicKeys
)
(builtins.attrNames nixosConfigurations)
);
hostSshConfigs = concatMapStrings
(hostName: ''
Host ${hostName}
HostName ${nixosConfigurations.${hostName}.config.sconfig.morph.deployment.targetHost}
'')
(builtins.attrNames nixosConfigurations);
sshConfig = pkgs.writeText "ssh_config" ''
StrictHostKeyChecking yes
GlobalKnownHostsFile ${sshKnownHostsTxt}
${hostSshConfigs}
Host *
User root
'';
jump = pkgs.writeShellScript "jump" ''
set -eu
echo ${self}
ip="$(nix eval --raw ".#nixosConfigurations.\"$1\".config.sconfig.morph.deployment.targetHost")"
NIX_SSHOPTS="-F${sshConfig}" nix copy --to ssh://root@$ip ${self}
exec ssh -oForwardAgent=yes -F"${sshConfig}" "root@$ip" -t "cd ${self}; nix develop"
'';
check-updates = pkgs.writeShellScript "check-updates" ''
set -eu
export SSH_CONFIG_FILE=${sshConfig}
res="$(morph build morph.nix)"
diff \
<(find $res -type l | xargs readlink | sort) \
<(morph exec morph.nix 'readlink /run/current-system' |& grep '^/nix/store/' | sort)
'';
livecd-deploy = pkgs.writeShellScript "livecd-deploy" ''
set -eux
config=".#nixosConfigurations.\"$1\".config"
ip="$(nix eval --raw "$config.sconfig.morph.deployment.targetHost")"
ssh-copy-id root@$ip
sys="$(nix eval --raw "$config.system.build.toplevel")"
nix build "$config.system.build.toplevel" --out-link "$(mktemp -d)/result"
nix copy --to ssh://root@$ip?remote-store=local?root=/mnt "$sys"
ssh root@$ip nix-env --store /mnt -p /mnt/nix/var/nix/profiles/system --set "$sys"
ssh root@$ip mkdir /mnt/etc
ssh root@$ip touch /mnt/etc/NIXOS
ssh root@$ip ln -sfn /proc/mounts /mnt/etc/mtab
ssh root@$ip NIXOS_INSTALL_BOOTLOADER=1 nixos-enter \
--root /mnt -- /run/current-system/bin/switch-to-configuration boot
'';
in
{ inherit check-updates jump livecd-deploy pkgs sshConfig; };
in
{
devShell = system: with helpers system;
pkgs.mkShell {
buildInputs = [ pkgs.morph ];
shellHook = ''
export SSH_CONFIG_FILE=${sshConfig}
alias ssh='ssh -F${sshConfig}'
alias jump=${jump}
alias check-updates=${check-updates}
alias livecd-deploy=${livecd-deploy}
'';
};
morph-entrypoint = system:
let
globalHealthChecks.cmd = [
{
cmd = [ "nixos-check-reboot" ];
description = "Check for pending reboot";
}
{
cmd = [ "systemctl is-system-running" ];
description = "Check services are running";
}
];
getConfig = name: value: { ... }: {
imports = extraMorphModules ++ nixosConfigurations.${name}.extraArgs.modules;
config = nixpkgs.lib.mkMerge [
{ inherit (value.config.sconfig.morph) deployment; }
{ deployment.healthChecks = globalHealthChecks; }
];
};
in
{ network.pkgs = nixpkgs.legacyPackages.${system}; } //
builtins.mapAttrs getConfig nixosConfigurations;
}