Flakeify home config

Use nix flakes instead of niv for pinning dependency channels.

First step towards merging my "nixos-system" and "nixos-home"
configs into a single trivially reproducible flake setup.

Apply home config via:

> nix build .#homeManagerConfigurations.common.activationPackage --impure
> ./result/activate

9 files changed, 161 insertions, 292 deletions

diff --git a/custom.nix b/custom.nix
index 918460a..38a0046 100644
--- a/custom.nix
+++ b/custom.nix
@@ -3,6 +3,7 @@
 let
   mkOption = pkgs.lib.mkOption;
   types = pkgs.lib.types;
+
 in {
   options.custom = {
     hidpi = mkOption {
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..bfd9fd9
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,96 @@
+{
+  "nodes": {
+    "emacs": {
+      "locked": {
+        "lastModified": 1629250486,
+        "narHash": "sha256-L9izjLJUC9wzANrWAEYB1srD7Mf10XXtm3nv2XJHTcM=",
+        "owner": "nix-community",
+        "repo": "emacs-overlay",
+        "rev": "203f890b687c2d981200130549bda4df65349789",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "ref": "master",
+        "repo": "emacs-overlay",
+        "type": "github"
+      }
+    },
+    "home-manager": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1627649712,
+        "narHash": "sha256-AJBasvMKpsyJmCLdjroBElCHY5AlalbVy+XY5vjbgXc=",
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "rev": "b39647e52ed3c0b989e9d5c965e598ae4c38d7ef",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "ref": "release-21.05",
+        "repo": "home-manager",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1629139728,
+        "narHash": "sha256-XuddZZNg61qSLsczyYGg/bugA+zR7I394Ev8A8SrdoY=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "94c989365d563238068841763ecc5f7f4b25b22c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-21.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-unstable": {
+      "locked": {
+        "lastModified": 1629169812,
+        "narHash": "sha256-krVVUNxRjSBJaFWKelNe0MWvxhklXSGKmisoJP4P5/Q=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "70dc433f2eb84cc7ed848a30feaa5aab5890d23c",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "personal": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-wQkw+oZMiSvWVVLWJ4AzsQk9uuqYmtWAElxhWGN6tPs=",
+        "type": "tarball",
+        "url": "https://pkgs.kummerlaender.eu/nixexprs.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://pkgs.kummerlaender.eu/nixexprs.tar.xz"
+      }
+    },
+    "root": {
+      "inputs": {
+        "emacs": "emacs",
+        "home-manager": "home-manager",
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-unstable": "nixpkgs-unstable",
+        "personal": "personal"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..7388919
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,49 @@
+{
+  description = "Computing environment of Adrian Kummerlaender";
+
+  inputs = {
+    nixpkgs.url = github:NixOS/nixpkgs/nixos-21.05;
+    nixpkgs-unstable.url = github:NixOS/nixpkgs/nixpkgs-unstable;
+    home-manager = {
+      url = github:nix-community/home-manager/release-21.05;
+      inputs = { nixpkgs.follows = "nixpkgs"; };
+    };
+    emacs.url = github:nix-community/emacs-overlay/master;
+    personal = {
+      url = https://pkgs.kummerlaender.eu/nixexprs.tar.xz;
+      flake = false;
+    };
+  };
+
+  outputs = { self, nixpkgs, nixpkgs-unstable, emacs, home-manager, personal, ... }: let
+    system = "x86_64-linux";
+
+    pkgs = import nixpkgs {
+      inherit system;
+      config = { allowUnfree = true; };
+    };
+
+  in {
+    homeManagerConfigurations = {
+      common = home-manager.lib.homeManagerConfiguration {
+        configuration = { pkgs, ... }: {
+          _module.args = {
+            pkgs-personal = import personal { };
+            pkgs-unstable = import nixpkgs-unstable {
+              inherit system;
+              config = { allowUnfree = true; };
+              overlays = [ emacs.overlay ];
+            };
+          };
+          imports = [ ./home.nix ];
+          nixpkgs = {
+            config = { allowUnfree = true; };
+          };
+        };
+        system = system;
+        homeDirectory = "/home/common";
+        username = "common";
+      };
+    };
+  };
+}
diff --git a/gui/emacs.nix b/gui/emacs.nix
index 6242cca..cec2bdf 100644
--- a/gui/emacs.nix
+++ b/gui/emacs.nix
@@ -1,11 +1,6 @@
-{ config, pkgs, sources, ... }:
+{ config, pkgs, pkgs-unstable, ... }:
 
-let
-  pkgs-unstable = import sources.nixpkgs-unstable {
-    overlays = [ (import sources.emacs-overlay) ];
-  };
-
-in {
+{
   programs.emacs = let
     akr-color-theme = pkgs.stdenv.mkDerivation {
       name = "emacs-color-theme-akr";
diff --git a/gui/email.nix b/gui/email.nix
index b1f3f0d..46d1731 100644
--- a/gui/email.nix
+++ b/gui/email.nix
@@ -1,15 +1,17 @@
 { pkgs, ... }:
 
 {
-  programs.mbsync.enable = true;
-  programs.msmtp.enable = true;
+  programs = {
+    mbsync.enable = true;
+    msmtp.enable = true;
+  };
 
   accounts.email = {
     maildirBasePath = "mail";
-    
+
     accounts.automatix = {
       primary = true;
-      
+
       realName = "Adrian Kummerländer";
       address  = "adrian@kummerlaender.eu";
 
diff --git a/home.nix b/home.nix
index 3f87e95..27a9bba 100644
--- a/home.nix
+++ b/home.nix
@@ -1,21 +1,14 @@
-{ config, pkgs, ... }:
+{ config, pkgs, pkgs-personal, ... }:
 
-let
-  sources = import ./nix/sources.nix;
-  pkgs = import sources.nixpkgs { };
-  pkgs-unstable = import sources.nixpkgs-unstable { };
-  pkgs-personal = import sources.mypkgs { };
-
-in {
-  _module.args.sources = sources;
-  _module.args.pkgs-unstable = pkgs-unstable;
-  _module.args.pkgs-personal = pkgs-personal;
-
-  imports = [
+{
+  imports = let
+  # impure access to system config
+    hostname = (import <nixpkgs/nixos> { }).config.networking.hostName;
+  in [
   # define options custom to this config
     ./custom.nix
   # load host specific stuff
-    ./host/current.nix
+    (./host + ("/" + hostname + ".nix"))
   # task shortcuts
     ./module/tasker.nix
     ./tasks/default.nix
diff --git a/nix/sources.json b/nix/sources.json
deleted file mode 100644
index b86348f..0000000
--- a/nix/sources.json
+++ /dev/null
@@ -1,75 +0,0 @@
-{
-    "emacs-overlay": {
-        "branch": "master",
-        "description": "Bleeding edge emacs overlay [maintainer=@adisbladis] ",
-        "homepage": "",
-        "owner": "nix-community",
-        "repo": "emacs-overlay",
-        "rev": "9da066d11fbedda841cae9d06c5391e1ebd65801",
-        "sha256": "16jc0653m1azaqbz5gbj92amqmj2kb44j1jvvmrlk45v9679fwfl",
-        "type": "tarball",
-        "url": "https://github.com/nix-community/emacs-overlay/archive/9da066d11fbedda841cae9d06c5391e1ebd65801.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "home-manager": {
-        "branch": "release-21.05",
-        "description": "Manage a user environment using Nix",
-        "homepage": "https://rycee.gitlab.io/home-manager/",
-        "owner": "rycee",
-        "repo": "home-manager",
-        "rev": "9c0abed5228d54aad120b4bc757b6f5935aeda1c",
-        "sha256": "05pfa26p9k1gpir9sniwg195cqqc9v6yp9b5f9hrjhlh3jm14bgq",
-        "type": "tarball",
-        "url": "https://github.com/rycee/home-manager/archive/9c0abed5228d54aad120b4bc757b6f5935aeda1c.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz",
-        "version": "20.03"
-    },
-    "mypkgs": {
-        "branch": "master",
-        "description": "Some custom Nix derivations",
-        "homepage": null,
-        "owner": "KnairdA",
-        "repo": "pkgs",
-        "rev": "122a6169f67f2b996b529ef2be6c4dbd74d4b166",
-        "sha256": "1yxlg9imhqaw2a0db6lqxax3s2di6f02gmjjapb2p2achvx302f1",
-        "type": "tarball",
-        "url": "https://github.com/KnairdA/pkgs/archive/122a6169f67f2b996b529ef2be6c4dbd74d4b166.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "niv": {
-        "branch": "master",
-        "description": "Easy dependency management for Nix projects",
-        "homepage": "https://github.com/nmattia/niv",
-        "owner": "nmattia",
-        "repo": "niv",
-        "rev": "e0ca65c81a2d7a4d82a189f1e23a48d59ad42070",
-        "sha256": "1pq9nh1d8nn3xvbdny8fafzw87mj7gsmp6pxkdl65w2g18rmcmzx",
-        "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/e0ca65c81a2d7a4d82a189f1e23a48d59ad42070.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs": {
-        "branch": "nixos-21.05",
-        "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
-        "homepage": "https://github.com/NixOS/nixpkgs",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "973910f5c31b9ba6c171c33a8bd7199990b14c72",
-        "sha256": "1n1kibmn1fcjazaxp8lydwdx646lknqksv5b2fm33fdq2dvafvj7",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/973910f5c31b9ba6c171c33a8bd7199990b14c72.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs-unstable": {
-        "branch": "nixpkgs-unstable",
-        "description": "Nix Packages collection",
-        "homepage": null,
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "ecaf3da9340231e5493eccc3db87604a3705da42",
-        "sha256": "049dcpzklpjj0c7g172njfcqb9xvxkpyf7qjiwvaf8klgd5cippa",
-        "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/ecaf3da9340231e5493eccc3db87604a3705da42.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    }
-}
diff --git a/nix/sources.nix b/nix/sources.nix
deleted file mode 100644
index 1938409..0000000
--- a/nix/sources.nix
+++ /dev/null
@@ -1,174 +0,0 @@
-# This file has been generated by Niv.
-
-let
-
-  #
-  # The fetchers. fetch_<type> fetches specs of type <type>.
-  #
-
-  fetch_file = pkgs: name: spec:
-    let
-      name' = sanitizeName name + "-src";
-    in
-      if spec.builtin or true then
-        builtins_fetchurl { inherit (spec) url sha256; name = name'; }
-      else
-        pkgs.fetchurl { inherit (spec) url sha256; name = name'; };
-
-  fetch_tarball = pkgs: name: spec:
-    let
-      name' = sanitizeName name + "-src";
-    in
-      if spec.builtin or true then
-        builtins_fetchTarball { name = name'; inherit (spec) url sha256; }
-      else
-        pkgs.fetchzip { name = name'; inherit (spec) url sha256; };
-
-  fetch_git = name: spec:
-    let
-      ref =
-        if spec ? ref then spec.ref else
-          if spec ? branch then "refs/heads/${spec.branch}" else
-            if spec ? tag then "refs/tags/${spec.tag}" else
-              abort "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
-    in
-      builtins.fetchGit { url = spec.repo; inherit (spec) rev; inherit ref; };
-
-  fetch_local = spec: spec.path;
-
-  fetch_builtin-tarball = name: throw
-    ''[${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.
-        $ niv modify ${name} -a type=tarball -a builtin=true'';
-
-  fetch_builtin-url = name: throw
-    ''[${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.
-        $ niv modify ${name} -a type=file -a builtin=true'';
-
-  #
-  # Various helpers
-  #
-
-  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
-  sanitizeName = name:
-    (
-      concatMapStrings (s: if builtins.isList s then "-" else s)
-        (
-          builtins.split "[^[:alnum:]+._?=-]+"
-            ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)
-        )
-    );
-
-  # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources: system:
-    let
-      sourcesNixpkgs =
-        import (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) { inherit system; };
-      hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
-      hasThisAsNixpkgsPath = <nixpkgs> == ./.;
-    in
-      if builtins.hasAttr "nixpkgs" sources
-      then sourcesNixpkgs
-      else if hasNixpkgsPath && ! hasThisAsNixpkgsPath then
-        import <nixpkgs> {}
-      else
-        abort
-          ''
-            Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
-            add a package called "nixpkgs" to your sources.json.
-          '';
-
-  # The actual fetching function.
-  fetch = pkgs: name: spec:
-
-    if ! builtins.hasAttr "type" spec then
-      abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then fetch_file pkgs name spec
-    else if spec.type == "tarball" then fetch_tarball pkgs name spec
-    else if spec.type == "git" then fetch_git name spec
-    else if spec.type == "local" then fetch_local spec
-    else if spec.type == "builtin-tarball" then fetch_builtin-tarball name
-    else if spec.type == "builtin-url" then fetch_builtin-url name
-    else
-      abort "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";
-
-  # If the environment variable NIV_OVERRIDE_${name} is set, then use
-  # the path directly as opposed to the fetched source.
-  replace = name: drv:
-    let
-      saneName = stringAsChars (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
-      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
-    in
-      if ersatz == "" then drv else
-        # this turns the string into an actual Nix path (for both absolute and
-        # relative paths)
-        if builtins.substring 0 1 ersatz == "/" then /. + ersatz else /. + builtins.getEnv "PWD" + "/${ersatz}";
-
-  # Ports of functions for older nix versions
-
-  # a Nix version of mapAttrs if the built-in doesn't exist
-  mapAttrs = builtins.mapAttrs or (
-    f: set: with builtins;
-    listToAttrs (map (attr: { name = attr; value = f attr set.${attr}; }) (attrNames set))
-  );
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
-  range = first: last: if first > last then [] else builtins.genList (n: first + n) (last - first + 1);
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
-  stringToCharacters = s: map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
-  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
-  concatMapStrings = f: list: concatStrings (map f list);
-  concatStrings = builtins.concatStringsSep "";
-
-  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
-  optionalAttrs = cond: as: if cond then as else {};
-
-  # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
-    let
-      inherit (builtins) lessThan nixVersion fetchTarball;
-    in
-      if lessThan nixVersion "1.12" then
-        fetchTarball ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-      else
-        fetchTarball attrs;
-
-  # fetchurl version that is compatible between all the versions of Nix
-  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
-    let
-      inherit (builtins) lessThan nixVersion fetchurl;
-    in
-      if lessThan nixVersion "1.12" then
-        fetchurl ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-      else
-        fetchurl attrs;
-
-  # Create the final "sources" from the config
-  mkSources = config:
-    mapAttrs (
-      name: spec:
-        if builtins.hasAttr "outPath" spec
-        then abort
-          "The values in sources.json should not have an 'outPath' attribute"
-        else
-          spec // { outPath = replace name (fetch config.pkgs name spec); }
-    ) config.sources;
-
-  # The "config" used by the fetchers
-  mkConfig =
-    { sourcesFile ? if builtins.pathExists ./sources.json then ./sources.json else null
-    , sources ? if isNull sourcesFile then {} else builtins.fromJSON (builtins.readFile sourcesFile)
-    , system ? builtins.currentSystem
-    , pkgs ? mkPkgs sources system
-    }: rec {
-      # The sources, i.e. the attribute set of spec name to spec
-      inherit sources;
-
-      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
-      inherit pkgs;
-    };
-
-in
-mkSources (mkConfig {}) // { __functor = _: settings: mkSources (mkConfig settings); }
diff --git a/shell.nix b/shell.nix
deleted file mode 100644
index 1e28dc1..0000000
--- a/shell.nix
+++ /dev/null
@@ -1,18 +0,0 @@
-let
-  sources = import ./nix/sources.nix;
-  pkgs = import sources.nixpkgs { };
-
-in pkgs.mkShell rec {
-  name = "home-manager";
-
-  buildInputs = [
-    pkgs.niv
-    (import sources.home-manager { inherit pkgs; }).home-manager
-  ];
-
-  shellHook = ''
-    export NIX_SHELL_NAME="${name}"
-    export NIX_PATH="nixpkgs=${sources.nixpkgs}:home-manager=${sources.home-manager}"
-  '';
-
-}