git.delta.rocks / jrsonnet / refs/commits / cc4ecd613a27

--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1432,6 +1432,7 @@
 name = "nix-eval"
 version = "0.1.0"
 dependencies = [
+ "anyhow",
  "better-command",
  "futures",
  "itertools",

--- a/README.adoc
+++ b/README.adoc
@@ -24,44 +24,33 @@
       url = "github:CertainLach/fleet";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    flake-parts.url = "github:hercules-ci/flake-parts";
     lanzaboote = {
       url = "github:nix-community/lanzaboote/v0.3.0";
       inputs.nixpkgs.follows = "nixpkgs";
     };
   };
-  outputs = {
-    nixpkgs,
-    fleet,
-    lanzaboote,
-    ...
-  }: {
-    # TODO: This section of documentation needs to use flake-utils.
-    formatter.x86_64-linux = let
-      pkgs = import nixpkgs {system = "x86_64-linux";};
-    in
-      pkgs.alejandra;
+  outputs = inputs: flake-parts.lib.mkFlake { inherit inputs; } {
+    imports = [inputs.fleet.flakeModules.default];
 
-    devShell.x86_64-linux = let
-      pkgs = import nixpkgs {
-        system = "x86_64-linux";
-      };
-    in
-      pkgs.mkShell {
-        buildInputs = with pkgs; [
-          fleet.packages.x86_64-linux.fleet
+    perSystem = {pkgs, system, ...}: {
+      _module.args.pkgs = import nixpkgs { inherit system; };
+
+      formatter = pkgs.alejandra;
+      devShells.default = pkgs.mkShell {
+        packages = [
+          inputs.fleet.packages.${system}.fleet
         ];
       };
+    };
 
     # Single flake may contain multiple fleet configurations, default one is called... `default`
-    fleetConfigurations.default = fleet.lib.fleetConfiguration {
+    fleetConfigurations.default = {
       # nixpkgs used to build the systems
-      inherit nixpkgs;
-      # fleet wants to pass some data, like secrets, to do that - fleet writes all the encrypted secrets to fleet.nix
-      # treat the contents of this file as implementation detail
-      data = import ./fleet.nix;
+      nixpkgs.buildUsing = nixpkgs;
       
-      # nixosModules section of fleet config declares modules, which are used for all configured nixos hosts.
-      nixosModules = [
+      # nixos option section of fleet config declares module, which is used for all configured nixos hosts.
+      nixos.imports = [
         lanzaboote.nixosModules.lanzaboote
         {
           # Make `nix shell nixpkgs#thing` use the same nixpkgs, as used to build the system.
@@ -77,7 +66,7 @@
       # Is I.e wiring up the mesh VPN, or deploying kubernetes, or other things.
       #
       # Modules use the same semantics as standard nixos module system, they are just configuring all the hosts at once.
-      fleetModules = [
+      imports = [
         ./wireguard
         # Multi-instancible modules example
         (import ./kubernetes {hosts = ["a" "b"];})
@@ -89,7 +78,7 @@
         # Every host has some system, for which the system configuration needs to be built
         system = "x86_64-linux";
         # And nixos modules
-        nixosModules = [
+        nixos.imports = [
           ./controlplane-1/hardware-configuration.nix
           ./controlplane-1/configuration.nix
           # Configuration may also be specified inline, as in any nixos config.

--- a/cmds/fleet/src/cmds/build_systems.rs
+++ b/cmds/fleet/src/cmds/build_systems.rs
@@ -254,13 +254,8 @@
 	let host = config.host(&host).await?;
 	// let action = Action::from(self.subcommand.clone());
 	let fleet_config = &config.config_field;
-	let drv = nix_go!(
-		fleet_config.hosts[{ &host.name }]
-			.nixosSystem
-			.config
-			.system
-			.build[{ build_attr }]
-	);
+	let nixos = host.nixos_config().await?;
+	let drv = nix_go!(nixos.system.build[{ build_attr }]);
 	let outputs = drv.build().await.inspect_err(|_| {
 			if build_attr == "sdImage" {
 				info!("sd-image build failed");
@@ -335,6 +330,7 @@
 			let config = config.clone();
 			let span = info_span!("deploy", host = field::display(&host.name));
 			let hostname = host.name.clone();
+			let local_host = config.local_host();
 			// FIXME: Fix repl concurrency (see build-systems)
 			set.spawn_local(
 				(async move {
@@ -354,7 +350,10 @@
 							// at least for the first deployment, to provide trusted store key.
 							//
 							// It is much slower, yet doesn't require root on the deployer machine.
-							let mut sign = MyCommand::new("nix");
+							let Ok(mut sign) = local_host.cmd("nix").await else {
+								error!("failed to setup local");
+								return;
+							};
 							// Private key for host machine is registered in nix-sign.nix
 							sign.arg("store")
 								.arg("sign")
@@ -362,7 +361,7 @@
 								.arg("-r")
 								.arg(&built);
 							if let Err(e) = sign.sudo().run_nix().await {
-								warn!("Failed to sign store paths: {e}");
+								warn!("failed to sign store paths: {e}");
 							};
 						}
 						let mut tries = 0;

--- a/cmds/fleet/src/cmds/info.rs
+++ b/cmds/fleet/src/cmds/info.rs
@@ -38,9 +38,9 @@
 			InfoCmd::ListHosts { ref tagged } => {
 				'host: for host in config.list_hosts().await? {
 					if !tagged.is_empty() {
-						let config = &config.config_unchecked_field;
+						let config = &config.config_field;
 						let tags: Vec<String> =
-							nix_go_json!(config.hosts[{ host.name }].nixosSystem.config.tags);
+							nix_go_json!(config.hosts[{ host.name }].tags);
 						for tag in tagged {
 							if !tags.contains(tag) {
 								continue 'host;

--- a/cmds/fleet/src/cmds/secrets/mod.rs
+++ b/cmds/fleet/src/cmds/secrets/mod.rs
@@ -598,7 +598,7 @@
 					return Ok(());
 				}
 
-				let config_field = &config.config_unchecked_field;
+				let config_field = &config.config_field;
 				let field = nix_go!(config_field.sharedSecrets[{ name }]);
 
 				let updated = update_owner_set(
@@ -623,7 +623,7 @@
 						.collect::<HashSet<_>>();
 					let shared_set = config.list_shared().into_iter().collect::<HashSet<_>>();
 					for missing in expected_shared_set.difference(&shared_set) {
-						let config_field = &config.config_unchecked_field;
+						let config_field = &config.config_field;
 						let secret = nix_go!(config_field.sharedSecrets[{ missing }]);
 						let expected_owners: Option<Vec<String>> =
 							nix_go_json!(secret.expectedOwners);
@@ -675,7 +675,7 @@
 				for name in &config.list_shared() {
 					info!("updating secret: {name}");
 					let data = config.shared_secret(name)?;
-					let config_field = &config.config_unchecked_field;
+					let config_field = &config.config_field;
 					let expected_owners: Vec<String> =
 						nix_go_json!(config_field.sharedSecrets[{ name }].expectedOwners);
 					if expected_owners.is_empty() {

--- a/cmds/fleet/src/command.rs
+++ b/cmds/fleet/src/command.rs
@@ -9,6 +9,8 @@
 use tokio_util::codec::{BytesCodec, FramedRead, LinesCodec};
 use tracing::debug;
 
+use crate::host::EscalationStrategy;
+
 fn escape_bash(input: &str, out: &mut String) {
 	const TO_ESCAPE: &str = "$ !\"#&'()*,;<>?[\\]^`{|}";
 	if input.chars().all(|c| !TO_ESCAPE.contains(c)) {
@@ -27,32 +29,51 @@
 fn ostoutf8(os: impl AsRef<OsStr>) -> String {
 	os.as_ref().to_str().expect("non-utf8 data").to_owned()
 }
-#[derive(Clone)]
+
+#[derive(Clone, Debug)]
 pub struct MyCommand {
 	command: String,
 	args: Vec<String>,
 	env: Vec<(String, String)>,
 	ssh_session: Option<Arc<Session>>,
+	escalation: EscalationStrategy,
+	escalate: bool,
 }
 impl MyCommand {
-	pub fn new_on(cmd: impl AsRef<OsStr>, session: Arc<Session>) -> Self {
+	pub fn new_on(
+		escalation: EscalationStrategy,
+		cmd: impl AsRef<OsStr>,
+		session: Arc<Session>,
+	) -> Self {
 		assert!(!cmd.as_ref().is_empty());
 		Self {
 			command: ostoutf8(cmd),
 			args: vec![],
 			env: vec![],
 			ssh_session: Some(session),
+			escalation,
+			escalate: false,
 		}
 	}
-	pub fn new(cmd: impl AsRef<OsStr>) -> Self {
+	pub fn new(escalation: EscalationStrategy, cmd: impl AsRef<OsStr>) -> Self {
 		assert!(!cmd.as_ref().is_empty());
 		Self {
 			command: ostoutf8(cmd),
 			args: vec![],
 			env: vec![],
 			ssh_session: None,
+			escalation,
+			escalate: false,
 		}
 	}
+	fn new_here(&self, cmd: impl AsRef<OsStr>) -> Self {
+		if let Some(ssh_session) = self.ssh_session.clone() {
+			Self::new_on(self.escalation, cmd, ssh_session)
+		} else {
+			Self::new(self.escalation, cmd)
+		}
+	}
+
 	fn into_args(self) -> Vec<String> {
 		let mut out = Vec::new();
 		if !self.env.is_empty() {
@@ -76,8 +97,7 @@
 		if self.env.is_empty() {
 			return self;
 		}
-		let mut out = Self::new("env");
-		out.ssh_session = self.ssh_session;
+		let mut out = self.new_here("env");
 		for (k, v) in self.env {
 			assert!(!k.contains('='));
 			out.arg(format!("{k}={v}"));
@@ -160,26 +180,46 @@
 		self
 	}
 	pub fn sudo(mut self) -> Self {
-		// TODO: Multiple escalation strategies.
-		// Maybe escalation should be moved to ConfigHost, to also support cases
-		// when there is no sudo on remote machine, but instead we can reconnect
-		// as root using ssh?
-		if std::env::var_os("NO_SUDO").is_some() {
-			let mut out = Self::new("su");
-			out.ssh_session = self.ssh_session.take();
-			out.arg("-c").arg(self.into_string());
-			out
-		} else {
-			let mut out = Self::new("sudo");
-			out.ssh_session = self.ssh_session.take();
-			out.args(self.into_args());
-			out
+		self.escalate = true;
+		self
+	}
+	fn wrap_sudo_if_needed(self) -> Self {
+		if !self.escalate {
+			return self;
+		}
+		match self.escalation {
+			EscalationStrategy::Su => {
+				let mut out = self.new_here("su");
+				out.arg("-c").arg(self.into_string());
+				out
+			}
+			EscalationStrategy::Sudo => {
+				let mut out = self.new_here("sudo");
+				out.args(self.into_args());
+				out
+			}
+			EscalationStrategy::Run0 => {
+				// run0 wants interactive authentication by default.
+				let mut run0 = self.new_here("run0");
+				let mut out = self.new_here("script");
+
+				// Red backgrounds messes with fleet formatting
+				run0.arg("--background=");
+				run0.args(self.into_args());
+
+				out.arg("-q");
+				out.arg("/dev/null");
+				out.arg("-c");
+				out.arg(run0.into_string());
+				dbg!(&out);
+				out
+			}
 		}
 	}
 
 	pub async fn run(self) -> Result<()> {
 		let str = self.clone().into_string();
-		let cmd = self.into_command_new()?;
+		let cmd = self.wrap_sudo_if_needed().into_command_new()?;
 		match cmd {
 			Either::Left(cmd) => run_nix_inner(str, cmd, &mut PlainHandler).await?,
 			Either::Right(cmd) => run_nix_inner_ssh(str, cmd, &mut PlainHandler).await?,
@@ -192,7 +232,7 @@
 	}
 	pub async fn run_bytes(self) -> Result<Vec<u8>> {
 		let str = self.clone().into_string();
-		let cmd = self.into_command_new()?;
+		let cmd = self.wrap_sudo_if_needed().into_command_new()?;
 		let v = match cmd {
 			Either::Left(cmd) => run_nix_inner_stdout(str, cmd, &mut PlainHandler).await?,
 			Either::Right(cmd) => run_nix_inner_stdout_ssh(str, cmd, &mut PlainHandler).await?,
@@ -200,17 +240,17 @@
 		Ok(v)
 	}
 
-	pub async fn run_nix_string(self) -> Result<String> {
+	pub async fn run_nix_string(mut self) -> Result<String> {
 		let str = self.clone().into_string();
-		let mut cmd = self.into_command();
-		cmd.arg("--log-format").arg("internal-json");
+		self.arg("--log-format").arg("internal-json");
+		let mut cmd = self.wrap_sudo_if_needed().into_command();
 		let bytes = run_nix_inner_stdout(str, cmd, &mut NixHandler::default()).await?;
 		Ok(String::from_utf8(bytes)?)
 	}
-	pub async fn run_nix(self) -> Result<()> {
+	pub async fn run_nix(mut self) -> Result<()> {
 		let str = self.clone().into_string();
-		let mut cmd = self.into_command();
-		cmd.arg("--log-format").arg("internal-json");
+		self.arg("--log-format").arg("internal-json");
+		let mut cmd = self.wrap_sudo_if_needed().into_command();
 		cmd.stdout(Stdio::inherit());
 		run_nix_inner(str, cmd, &mut NixHandler::default()).await
 	}

--- a/cmds/fleet/src/main.rs
+++ b/cmds/fleet/src/main.rs
@@ -58,7 +58,7 @@
 				path.push("file://");
 				path.push(entry.path());
 
-				let mut status = MyCommand::new("nix");
+				let mut status = config.local_host().cmd("nix").await?;
 				status.args(&config.nix_args);
 				status.arg("store").arg("prefetch-file").arg(path);
 				status.run_nix_string().instrument(span).await?;

--- a/crates/nix-eval/Cargo.toml
+++ b/crates/nix-eval/Cargo.toml
@@ -5,6 +5,7 @@
 build = "build.rs"
 
 [dependencies]
+anyhow.workspace = true
 better-command.workspace = true
 futures = "0.3.30"
 itertools = "0.13.0"

--- a/crates/nix-eval/src/lib.rs
+++ b/crates/nix-eval/src/lib.rs
@@ -17,6 +17,7 @@
 // Contains macros helpers
 #[doc(hidden)]
 pub mod macros;
+pub mod util;
 // #[allow(non_upper_case_globals, non_camel_case_types, non_snake_case)]
 // mod nix_raw {
 // 	include!(concat!(env!("OUT_DIR"), "/bindings.rs"));

--- a/crates/nix-eval/src/value.rs
+++ b/crates/nix-eval/src/value.rs
@@ -44,14 +44,14 @@
 				let v = nixlike::format_identifier(k.as_str());
 				write!(f, ".{v}")
 			}
-			Index::Apply(o) => {
-				write!(f, "<apply>({o})")
+			Index::Apply(_) => {
+				write!(f, "<apply>(...)")
 			}
 			Index::Expr(e) => {
 				write!(f, "[{}]", e.out)
 			}
-			Index::ExprApply(e) => {
-				write!(f, "<apply>({})", e.out)
+			Index::ExprApply(_) => {
+				write!(f, "<apply>(...)")
 			}
 			Index::Pipe(e) => {
 				write!(f, "<map>({})", e.out)

--- a/flake.nix
+++ b/flake.nix
@@ -25,18 +25,23 @@
     flake-parts.lib.mkFlake {
       inherit inputs;
     } {
-      flake = let
-        inherit (inputs.nixpkgs.lib) mapAttrs;
-      in {
-        lib = import ./lib {
-          fleetPkgsForPkgs = pkgs:
-            import ./pkgs {
-              inherit (pkgs) callPackage;
-              craneLib = crane.mkLib pkgs;
-            };
-        };
+      flake = rec {
+        lib =
+          (import ./lib {
+            inherit (inputs.nixpkgs) lib;
+          })
+          // {
+            fleetConfiguration = throw "function-based interface is deprecated, use flake-parts syntax instead";
+          };
+        flakeModules.default = (import ./lib/flakePart.nix {
+          inherit crane;
+        });
+        flakeModule = flakeModules.default;
+
         # To be used with https://github.com/NixOS/nix/pull/8892
-        schemas = {
+        schemas = let
+          inherit (inputs.nixpkgs.lib) mapAttrs;
+        in {
           fleetConfigurations = {
             version = 1;
             doc = ''
@@ -69,7 +74,8 @@
         pkgs,
         ...
       }: let
-        inherit (lib) mapAttrs' elem;
+        inherit (lib.attrSets) mapAttrs';
+        inherit (lib.lists) elem;
         # Can also be built for darwin, through it is not usual to deploy nixos systems from macos machines.
         # I have no hardware for such testing, thus only adding machines I actually have and use.
         #
@@ -108,6 +114,7 @@
               pkg-config
               openssl
               bacon
+              nil
             ];
           };
         };

--- a/lib/default.nix
+++ b/lib/default.nix
@@ -1,60 +1,121 @@
-{fleetPkgsForPkgs}: {
-  fleetConfiguration = {
-    # TODO: Provide by fleet, instead of requesting user to provide it.
-    # This is not good that user needs to provide it, as it becomes a flake data, and fleet arbitrarily rewriting it
-    # always dirnets the flake. Instead, fleetConfiguration should return function, parameters of which should be filled
-    # by fleet itself, which is possible since fleet moving to nix repl execution.
-    data,
-    nixpkgs,
-    overlays ? [],
-    hosts,
-    fleetModules,
-    nixosModules ? [],
-    extraFleetLib ? {},
-  }: let
-    hostNames = nixpkgs.lib.attrNames hosts;
-    fleetLib =
-      (import ./fleetLib.nix {
-        inherit nixpkgs hostNames;
-      })
-      // extraFleetLib;
-  in let
-    root = nixpkgs.lib.evalModules {
-      modules =
-        (import ../modules/fleet/_modules.nix)
-        ++ [
-          data
-          ({...}: {
-            inherit nixosModules hosts;
-            overlays = [(final: prev: (fleetPkgsForPkgs final))] ++ overlays;
-          })
-        ]
-        ++ fleetModules;
-      specialArgs = {
-        inherit nixpkgs fleetLib;
+# Shared functions for fleet configuration, available as `fleet` module argument
+{lib}: let
+  inherit (lib.trivial) isFunction;
+  inherit (lib.options) mkOption mergeOneOption;
+  inherit (lib.modules) mkOverride;
+  inherit (lib.types) listOf submodule attrsOf mkOptionType;
+  inherit (lib.strings) optionalString;
+in rec {
+  types = {
+    overlay = mkOptionType {
+      name = "nixpkgs-overlay";
+      description = "nixpkgs overlay";
+      check = isFunction;
+      merge = mergeOneOption;
+    };
+    listOfOverlay = listOf types.overlay;
+
+    mkHostsType = module: attrsOf (submodule module);
+  };
+
+  options = {
+    mkHostsOption = module:
+      mkOption {
+        type = types.mkHostsType module;
       };
-    };
-    failedAssertions = map (x: x.message) (nixpkgs.lib.filter (x: !x.assertion) root.config.assertions);
-    checkedRoot =
-      if failedAssertions != []
-      then throw "Fleet failed assertions:\n${nixpkgs.lib.concatStringsSep "\n" (map (x: "- ${x}") failedAssertions)}"
-      else nixpkgs.lib.showWarnings root.config.warnings root;
-    withData = {
-      root,
-      data,
-    }: {
-      config = root.config;
-    };
-    defaultData = withData {
-      inherit data;
-      root = checkedRoot;
-    };
-    uncheckedData = withData {inherit data root;};
-  in {
-    inherit nixpkgs overlays;
-    inherit (defaultData) config;
-    unchecked = {
-      inherit (uncheckedData) config;
-    };
   };
+
+  inherit (options) mkHostsOption;
+
+  modules = {
+    # mkDefault = mkOverride 1000
+    # For places, where fleet knows better than nixpkgs defaults.
+    mkFleetDefault = mkOverride 999;
+    # Some generators use mkDefault, but optionDefault is set by nixpkgs.
+    mkFleetGeneratorDefault = mkOverride 1001;
+  };
+
+  inherit (modules) mkFleetDefault mkFleetGeneratorDefault;
+
+  secrets = {
+    mkPassword = {size ? 32}: {
+      coreutils,
+      mkSecretGenerator,
+      ...
+    }:
+      mkSecretGenerator {
+        script = ''
+          mkdir $out
+          gh generate password -o $out/secret --size ${toString size}
+        '';
+      };
+
+    mkEd25519 = {
+      noEmbedPublic ? false,
+      encoding ? null,
+    }: {mkSecretGenerator, ...}:
+      mkSecretGenerator {
+        script = ''
+          mkdir $out
+          gh generate ed25519 -p $out/public -s $out/secret \
+            ${optionalString noEmbedPublic "--no-embed-public"} \
+            ${optionalString (encoding != null) "--encoding=${encoding}"}
+        '';
+      };
+
+    mkX25519 = {encoding ? null}: {mkSecretGenerator, ...}:
+      mkSecretGenerator {
+        script = ''
+          mkdir $out
+          gh generate x25519 -p $out/public -s $out/secret \
+            ${optionalString (encoding != null) "--encoding=${encoding}"}
+        '';
+      };
+
+    mkRsa = {size ? 4096}: {
+      openssl,
+      mkSecretGenerator,
+      ...
+    }:
+      mkSecretGenerator {
+        script = ''
+          mkdir $out
+
+          ${openssl}/bin/openssl genrsa -out rsa_private.key ${toString size}
+          ${openssl}/bin/openssl rsa -in rsa_private.key -pubout -out rsa_public.key
+
+          cat rsa_private.key | gh private -o $out/secret
+          cat rsa_public.key | gh public -o $out/public
+        '';
+      };
+
+    mkBytes = {
+      count ? 32,
+      encoding,
+      noNuls ? false,
+    }: {mkSecretGenerator, ...}:
+      mkSecretGenerator {
+        script = ''
+          mkdir $out
+          gh generate bytes --count=${toString count} --encoding=${encoding} -o $out/secret \
+            ${optionalString noNuls "--no-nuls"}
+        '';
+      };
+    mkHexBytes = {count ? 32}:
+      mkBytes {
+        inherit count;
+        encoding = "hex";
+      };
+    mkBase64Bytes = {count ? 32}:
+      mkBytes {
+        inherit count;
+        encoding = "base64";
+      };
+
+    # Wireguard
+    # mkWireguard = {}: mkX25519 {encoding = "base64";};
+    # mkWireguardPsk = {}: mkBase64Bytes {count = 32;};
+  };
+
+  inherit (secrets) mkPassword mkEd25519 mkX25519 mkRsa mkBytes mkHexBytes mkBase64Bytes;
 }

--- a/modules/fleet/_modules.nix
+++ b/modules/fleet/_modules.nix
@@ -1,5 +1,9 @@
 [
   ./assertions.nix
+  ./fleetLib.nix
+  ./hosts.nix
   ./meta.nix
+  ./nixos.nix
+  ./nixpkgs.nix
   ./secrets.nix
 ]

--- a/modules/fleet/assertions.nix
+++ b/modules/fleet/assertions.nix
@@ -1,6 +1,11 @@
-{lib, ...}: let
-  inherit (lib) mkOption;
+{
+  lib,
+  config,
+  ...
+}: let
+  inherit (lib.options) mkOption;
   inherit (lib.types) listOf unspecified str;
+  inherit (lib.lists) map filter;
 in {
   options = {
     assertions = mkOption {
@@ -30,6 +35,15 @@
         the evaluation of the system configuration.
       '';
     };
+    errors = mkOption {
+      type = listOf str;
+      internal = true;
+      description = ''
+        Similar to warnings, however build will fail if any error exists.
+      '';
+    };
   };
-  # impl of assertions is in <fleet/lib/default.nix>
+  config.errors =
+    map (v: v.message)
+    (filter (v: !v.assertion) config.assertions);
 }

--- a/modules/fleet/meta.nix
+++ b/modules/fleet/meta.nix
@@ -1,89 +1,8 @@
-{
-  lib,
-  fleetLib,
-  config,
-  nixpkgs,
-  ...
-}: let
-  inherit (fleetLib) hostsToAttrs mkFleetGeneratorDefault;
-  inherit (fleetLib.types) listOfAnyModule;
-  inherit (lib) mkOption mkOptionType;
-  inherit (lib.types) str unspecified attrsOf listOf submodule;
-  hostModule = {...} @ hostConfig: let
-    hostName = hostConfig.config._module.args.name;
-  in {
-    options = {
-      nixosModules = mkOption {
-        # Not too strict, but nixos module system will fix everything.
-        type =
-          listOfAnyModule;
-
-        description = "List of nixos modules";
-        default = [];
-      };
-      system = mkOption {
-        type = str;
-        description = "Type of system";
-      };
-      encryptionKey = mkOption {
-        type = str;
-        description = "Encryption key";
-      };
-      nixosSystem = mkOption {
-        type = unspecified;
-        description = "Nixos configuration";
-      };
-      nixpkgs = mkOption {
-        type = unspecified;
-        description = "Nixpkgs override";
-        default = nixpkgs;
-      };
-    };
-    config = {
-      nixosSystem = hostConfig.config.nixpkgs.lib.nixosSystem {
-        inherit (hostConfig.config) system;
-        modules = hostConfig.config.nixosModules;
-        specialArgs = {
-          inherit fleetLib;
-          fleet = hostsToAttrs (host: config.hosts.${host}.nixosSystem.config);
-        };
-      };
-      nixosModules.networking.hostName = mkFleetGeneratorDefault hostName;
-    };
-  };
-  overlayType = mkOptionType {
-    name = "nixpkgs-overlay";
-    description = "nixpkgs overlay";
-    check = lib.isFunction;
-    merge = lib.mergeOneOption;
-  };
+{lib, ...}: let
+  inherit (lib.modules) mkRemovedOptionModule;
 in {
-  options = {
-    hosts = mkOption {
-      type = attrsOf (submodule hostModule);
-      default = {};
-      description = "Configurations of individual hosts";
-    };
-    nixosModules = mkOption {
-      type = listOfAnyModule;
-      description = "Modules, which should be added to every system";
-      default = [];
-    };
-    overlays = mkOption {
-      default = [];
-      type = listOf overlayType;
-    };
-  };
-  config = {
-    hosts = hostsToAttrs (host: {
-      nixosModules =
-        config.nixosModules
-        ++ [
-          {
-            nixpkgs.overlays = config.overlays;
-          }
-        ];
-    });
-    nixosModules = import ../../nixos/modules/module-list.nix;
-  };
+  imports = [
+    (mkRemovedOptionModule ["fleetModules"] "replaced with imports.")
+    (mkRemovedOptionModule ["data"] "data is now provided by fleet itself, you can remove your import.")
+  ];
 }

--- a/modules/fleet/secrets.nix
+++ b/modules/fleet/secrets.nix
@@ -4,9 +4,12 @@
   config,
   ...
 }: let
-  inherit (fleetLib) hostsToAttrs;
-  inherit (lib) mkOption mapAttrsToList mapAttrs filterAttrs concatStringsSep;
+  inherit (fleetLib.options) mkHostsOption;
+  inherit (lib.options) mkOption;
   inherit (lib.types) lazyAttrsOf unspecified nullOr listOf str bool attrsOf submodule;
+  inherit (lib.lists) sort elem;
+  inherit (lib.attrsets) mapAttrsToList mapAttrs filterAttrs;
+  inherit (lib.strings) toJSON concatStringsSep;
 
   sharedSecret = {config, ...}: {
     freeformType = lazyAttrsOf unspecified;
@@ -82,11 +85,11 @@
       };
     };
   };
+  inherit (config) hostSecrets sharedSecrets;
 in {
   options = {
     version = mkOption {
       type = str;
-      default = "";
       internal = true;
     };
     sharedSecrets = mkOption {
@@ -100,36 +103,34 @@
       description = "Host secrets. Imported from fleet.nix";
       internal = true;
     };
+    hosts = mkHostsOption ({config, ...}: {
+      nixos = {
+        secrets = let
+          host = config._module.args.name;
+          processSecret = v:
+            (removeAttrs v ["createdAt" "expiresAt" "expectedOwners" "owners" "regenerateOnOwnerAdded" "regenerateOnOwnerRemoved"])
+            // {
+              shared = true;
+            };
+        in
+          (
+            mapAttrs (_: processSecret)
+            (filterAttrs (_: v: elem host v.owners) sharedSecrets)
+          )
+          // (mapAttrs (_: processSecret) (hostSecrets.${host} or {}));
+        _file = ./secrets.nix;
+      };
+    });
   };
   config = {
     assertions =
       mapAttrsToList
       (name: secret: {
-        assertion = secret.expectedOwners == null || builtins.sort (a: b: a < b) secret.owners == builtins.sort (a: b: a < b) secret.expectedOwners;
-        message = "Shared secret ${name} is expected to be encrypted for ${builtins.toJSON secret.expectedOwners}, but it is encrypted for ${builtins.toJSON secret.owners}. Run fleet secrets regenerate to fix";
+        assertion = secret.expectedOwners == null || sort (a: b: a < b) secret.owners == sort (a: b: a < b) secret.expectedOwners;
+        message = "Shared secret ${name} is expected to be encrypted for ${toJSON secret.expectedOwners}, but it is encrypted for ${toJSON secret.owners}. Run fleet secrets regenerate to fix";
       })
       config.sharedSecrets;
-    hosts = hostsToAttrs (host: {
-      nixosModules = let
-        # processPart
-        processSecret = v:
-          (removeAttrs v ["createdAt" "expiresAt" "expectedOwners" "owners" "regenerateOnOwnerAdded" "regenerateOnOwnerRemoved"])
-          // {
-            shared = true;
-          };
-      in [
-        {
-          secrets =
-            (
-              mapAttrs (_: processSecret)
-              (filterAttrs (_: v: builtins.elem host v.owners) config.sharedSecrets)
-            )
-            // (mapAttrs (_: processSecret) (config.hostSecrets.${host} or {}));
-        }
-      ];
-    });
-    # TODO: Should this attribute be moved to `nixpkgs.overlays`?
-    overlays = [
+    nixpkgs.overlays = [
       (final: prev: {
         mkSecretGenerators = {recipients}: rec {
           # TODO: Merge both generators to one with consistent options syntax?

--- a/nixos/meta.nix
+++ b/nixos/meta.nix
@@ -3,18 +3,16 @@
   pkgs,
   ...
 }: let
-  inherit (lib) mkOption;
+  inherit (lib.options) mkOption;
   inherit (lib.types) listOf str submodule;
+  inherit (lib.modules) mkRemovedOptionModule;
 in {
   options = {
-    nixpkgs.resolvedPkgs = mkOption {
+    # TODO: Give a real name.
+    # Previously it was nixpkgs.resolvedPkgs, which was erroreously merged with nixpkgs override attribute.
+    _resolvedPkgs = mkOption {
       type = lib.types.pkgs // {description = "nixpkgs.pkgs";};
       description = "Value of pkgs";
-    };
-    tags = mkOption {
-      type = listOf str;
-      description = "Host tags";
-      default = [];
     };
     network = mkOption {
       type = submodule {
@@ -34,9 +32,11 @@
       description = "Network definition of host";
     };
   };
+  imports = [
+    (mkRemovedOptionModule ["tags"] "tags are now defined at the host level, not the nixos system level for fast filtering without evaluating unnecessary hosts.")
+  ];
   config = {
-    tags = ["all"];
     network = {};
-    nixpkgs.resolvedPkgs = pkgs;
+    _resolvedPkgs = pkgs;
   };
 }

--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -1,4 +1,5 @@
 [
+  ../assertions.nix
   ../meta.nix
   ../secrets.nix
   ../rollback.nix

--- a/nixos/nix-sign.nix
+++ b/nixos/nix-sign.nix
@@ -1,7 +1,12 @@
 # Required for nix copy in build_systems.rs
-{config, ...}: {
+{lib, config, ...}:
+let
+  inherit (lib.modules) mkIf;
+  hasPersistentHostname = config.networking.hostName != "";
+in
+{
   # https://github.com/NixOS/nix/issues/3023
-  systemd.services.generate-nix-cache-key = {
+  systemd.services.generate-nix-cache-key = mkIf hasPersistentHostname {
     wantedBy = ["multi-user.target"];
     serviceConfig.Type = "oneshot";
     path = [config.nix.package];
@@ -10,5 +15,5 @@
       nix-store --generate-binary-cache-key ${config.networking.hostName}-1 /etc/nix/private-key /etc/nix/public-key
     '';
   };
-  nix.settings.secret-key-files = "/etc/nix/private-key";
+  nix.settings.secret-key-files = mkIf hasPersistentHostname "/etc/nix/private-key";
 }

--- a/nixos/secrets.nix
+++ b/nixos/secrets.nix
@@ -5,7 +5,11 @@
   ...
 }: let
   inherit (lib.strings) hasPrefix removePrefix;
-  inherit (lib) mkOption mkOptionDefault mapAttrs stringAfter;
+  inherit (lib.stringsWithDeps) stringAfter;
+  inherit (lib.options) mkOption;
+  inherit (lib.lists) optional;
+  inherit (lib.attrsets) mapAttrs;
+  inherit (lib.modules) mkOptionDefault mkIf;
   inherit (lib.types) submodule str attrsOf nullOr unspecified lazyAttrsOf;
   plaintextPrefix = "<PLAINTEXT>";
   plaintextNewlinePrefix = "<PLAINTEXT-NL>";
@@ -110,6 +114,7 @@
       builtins.toJSON (mapAttrs (_: processSecret)
         config.secrets);
   };
+  useSysusers = (config.systemd ? sysusers && config.systemd.sysusers.enable) || (config ? userborn && config.userborn.enable);
 in {
   options = {
     secrets = mkOption {
@@ -120,21 +125,44 @@
   };
   config = {
     environment.systemPackages = [pkgs.fleet-install-secrets];
+
+    systemd.services.fleet-install-secrets = mkIf useSysusers {
+      wantedBy = ["sysinit.target"];
+      after = ["systemd-sysusers.service"];
+      restartTriggers = [
+        secretsFile
+      ];
+      aliases = [
+        "sops-install-secrets"
+        "agenix-install-secrets"
+      ];
+
+      unitConfig.DefaultDependencies = false;
+
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        ExecStart = "${pkgs.fleet-install-secrets}/bin/fleet-install-secrets install ${secretsFile}";
+      };
+    };
     system.activationScripts.decryptSecrets =
-      stringAfter (
-        [
-          # secrets are owned by user/group, thus we need to refer to those
-          "users"
-          "groups"
-          "specialfs"
-        ]
-        # nixos-impermanence compatibility: secrets are encrypted by host-key,
-        # but with impermanence we expect that the host-key is installed by
-        # persist-file activation script.
-        ++ (lib.optional (config.system.activationScripts ? "persist-files") "persist-files")
-      ) ''
-        1>&2 echo "setting up secrets"
-        ${pkgs.fleet-install-secrets}/bin/fleet-install-secrets install ${secretsFile}
-      '';
+      mkIf (!useSysusers)
+      (
+        stringAfter (
+          [
+            # secrets are owned by user/group, thus we need to refer to those
+            "users"
+            "groups"
+            "specialfs"
+          ]
+          # nixos-impermanence compatibility: secrets are encrypted by host-key,
+          # but with impermanence we expect that the host-key is installed by
+          # persist-file activation script.
+          ++ (optional (config.system.activationScripts ? "persist-files") "persist-files")
+        ) ''
+          1>&2 echo "setting up secrets"
+          ${pkgs.fleet-install-secrets}/bin/fleet-install-secrets install ${secretsFile}
+        ''
+      );
   };
 }