nixos: doc: move non-service parts of `service.nixosManual` to `documentation.nixos`

8 files changed, 126 insertions, 109 deletions

diff --git a/nixos/lib/build-vms.nix b/nixos/lib/build-vms.nix
index 48288cf5962..4f65501f89c 100644
--- a/nixos/lib/build-vms.nix
+++ b/nixos/lib/build-vms.nix
@@ -28,7 +28,7 @@ rec {
       modules = configurations ++
         [ ../modules/virtualisation/qemu-vm.nix
           ../modules/testing/test-instrumentation.nix # !!! should only get added for automated test runs
-          { key = "no-manual"; services.nixosManual.enable = false; }
+          { key = "no-manual"; documentation.nixos.enable = false; }
           { key = "qemu"; system.build.qemu = qemu; }
         ] ++ optional minimal ../modules/testing/minimal-kernel.nix;
       extraArgs = { inherit nodes; };
diff --git a/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix b/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix
index 7ec09acd591..90a5128c02a 100644
--- a/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix
+++ b/nixos/modules/installer/cd-dvd/system-tarball-sheevaplug.nix
@@ -137,7 +137,7 @@ in
   # Setting vesa, we don't get the nvidia driver, which can't work in arm.
   services.xserver.videoDrivers = [ "vesa" ];
 
-  services.nixosManual.enable = false;
+  documentation.nixos.enable = false;
 
   # Include the firmware for various wireless cards.
   networking.enableRalinkFirmware = true;
diff --git a/nixos/modules/misc/documentation.nix b/nixos/modules/misc/documentation.nix
index e6ccda5d7f4..6a7105e9cda 100644
--- a/nixos/modules/misc/documentation.nix
+++ b/nixos/modules/misc/documentation.nix
@@ -1,8 +1,72 @@
-{ config, lib, pkgs, ... }:
+{ config, lib, pkgs, baseModules, ... }:
 
 with lib;
 
-let cfg = config.documentation; in
+let
+
+  cfg = config.documentation;
+
+  /* For the purpose of generating docs, evaluate options with each derivation
+    in `pkgs` (recursively) replaced by a fake with path "\${pkgs.attribute.path}".
+    It isn't perfect, but it seems to cover a vast majority of use cases.
+    Caveat: even if the package is reached by a different means,
+    the path above will be shown and not e.g. `${config.services.foo.package}`. */
+  manual = import ../../doc/manual rec {
+    inherit pkgs config;
+    version = config.system.nixos.release;
+    revision = "release-${version}";
+    options =
+      let
+        scrubbedEval = evalModules {
+          modules = [ { nixpkgs.localSystem = config.nixpkgs.localSystem; } ] ++ baseModules;
+          args = (config._module.args) // { modules = [ ]; };
+          specialArgs = { pkgs = scrubDerivations "pkgs" pkgs; };
+        };
+        scrubDerivations = namePrefix: pkgSet: mapAttrs
+          (name: value:
+            let wholeName = "${namePrefix}.${name}"; in
+            if isAttrs value then
+              scrubDerivations wholeName value
+              // (optionalAttrs (isDerivation value) { outPath = "\${${wholeName}}"; })
+            else value
+          )
+          pkgSet;
+      in scrubbedEval.options;
+  };
+
+  helpScript = pkgs.writeScriptBin "nixos-help"
+    ''
+      #! ${pkgs.runtimeShell} -e
+      # Finds first executable browser in a colon-separated list.
+      # (see how xdg-open defines BROWSER)
+      browser="$(
+        IFS=: ; for b in $BROWSER; do
+          [ -n "$(type -P "$b" || true)" ] && echo "$b" && break
+        done
+      )"
+      if [ -z "$browser" ]; then
+        browser="$(type -P xdg-open || true)"
+        if [ -z "$browser" ]; then
+          browser="$(type -P w3m || true)"
+          if [ -z "$browser" ]; then
+            echo "$0: unable to start a web browser; please set \$BROWSER"
+            exit 1
+          fi
+        fi
+      fi
+      exec "$browser" ${manual.manualHTMLIndex}
+    '';
+
+  desktopItem = pkgs.makeDesktopItem {
+    name = "nixos-manual";
+    desktopName = "NixOS Manual";
+    genericName = "View NixOS documentation in a web browser";
+    icon = "nix-snowflake";
+    exec = "${helpScript}/bin/nixos-help";
+    categories = "System";
+  };
+
+in
 
 {
 
@@ -66,6 +130,22 @@ let cfg = config.documentation; in
         '';
       };
 
+      nixos.enable = mkOption {
+        type = types.bool;
+        default = true;
+        description = ''
+          Whether to install NixOS's own documentation.
+          <itemizedlist>
+          <listitem><para>This includes man pages like
+                    <citerefentry><refentrytitle>configuration.nix</refentrytitle>
+                    <manvolnum>5</manvolnum></citerefentry> if <option>man.enable</option> is
+                    set.</para></listitem>
+          <listitem><para>This includes the HTML manual and the <command>nixos-help</command> command if
+                    <option>doc.enable</option> is set.</para></listitem>
+          </itemizedlist>
+        '';
+      };
+
     };
 
   };
@@ -99,6 +179,21 @@ let cfg = config.documentation; in
       environment.extraOutputsToInstall = [ "doc" ] ++ optional cfg.dev.enable "devdoc";
     })
 
+    (mkIf cfg.nixos.enable {
+      system.build.manual = manual;
+
+      environment.systemPackages = []
+        ++ optional cfg.man.enable manual.manpages
+        ++ optionals cfg.doc.enable ([ manual.manualHTML helpScript ]
+           ++ optionals config.services.xserver.enable [ desktopItem pkgs.nixos-icons ]);
+
+      services.mingetty.helpLine = mkIf cfg.doc.enable (
+          "\nRun `nixos-help` "
+        + optionalString config.services.nixosManual.showManual "or press <Alt-F${toString config.services.nixosManual.ttyNumber}> "
+        + "for the NixOS manual."
+      );
+    })
+
   ]);
 
 }
diff --git a/nixos/modules/profiles/installation-device.nix b/nixos/modules/profiles/installation-device.nix
index ff4a23a18d0..22d1af42694 100644
--- a/nixos/modules/profiles/installation-device.nix
+++ b/nixos/modules/profiles/installation-device.nix
@@ -22,7 +22,7 @@ with lib;
   config = {
 
     # Enable in installer, even if the minimal profile disables it.
-    services.nixosManual.enable = mkForce true;
+    documentation.nixos.enable = mkForce true;
 
     # Show the manual.
     services.nixosManual.showManual = true;
diff --git a/nixos/modules/profiles/minimal.nix b/nixos/modules/profiles/minimal.nix
index ed04e46c77d..dd81e61460c 100644
--- a/nixos/modules/profiles/minimal.nix
+++ b/nixos/modules/profiles/minimal.nix
@@ -12,7 +12,7 @@ with lib;
   i18n.supportedLocales = [ (config.i18n.defaultLocale + "/UTF-8") ];
 
   documentation.enable = mkDefault false;
-  services.nixosManual.enable = mkDefault false;
+  documentation.nixos.enable = mkDefault false;
 
   sound.enable = mkDefault false;
 }
diff --git a/nixos/modules/rename.nix b/nixos/modules/rename.nix
index 4a6bdfe83dd..bc9ff9f63dd 100644
--- a/nixos/modules/rename.nix
+++ b/nixos/modules/rename.nix
@@ -276,6 +276,7 @@ with lib;
 
     (mkRenamedOptionModule [ "programs" "info" "enable" ] [ "documentation" "info" "enable" ])
     (mkRenamedOptionModule [ "programs" "man"  "enable" ] [ "documentation" "man"  "enable" ])
+    (mkRenamedOptionModule [ "services" "nixosManual" "enable" ] [ "documentation" "nixos" "enable" ])
 
   ] ++ (flip map [ "blackboxExporter" "collectdExporter" "fritzboxExporter"
                    "jsonExporter" "minioExporter" "nginxExporter" "nodeExporter"
diff --git a/nixos/modules/services/misc/nixos-manual.nix b/nixos/modules/services/misc/nixos-manual.nix
index 37705e2a889..023a933fd89 100644
--- a/nixos/modules/services/misc/nixos-manual.nix
+++ b/nixos/modules/services/misc/nixos-manual.nix
@@ -1,89 +1,18 @@
-# This module includes the NixOS man-pages in the system environment,
-# and optionally starts a browser that shows the NixOS manual on one
-# of the virtual consoles.  The latter is useful for the installation
+# This module optionally starts a browser that shows the NixOS manual
+# on one of the virtual consoles which is useful for the installation
 # CD.
 
-{ config, lib, pkgs, baseModules, ... }:
+{ config, lib, pkgs, ... }:
 
 with lib;
 
-let
-
-  cfg = config.services.nixosManual;
-
-  /* For the purpose of generating docs, evaluate options with each derivation
-    in `pkgs` (recursively) replaced by a fake with path "\${pkgs.attribute.path}".
-    It isn't perfect, but it seems to cover a vast majority of use cases.
-    Caveat: even if the package is reached by a different means,
-    the path above will be shown and not e.g. `${config.services.foo.package}`. */
-  manual = import ../../../doc/manual rec {
-    inherit pkgs config;
-    version = config.system.nixos.release;
-    revision = "release-${version}";
-    options =
-      let
-        scrubbedEval = evalModules {
-          modules = [ { nixpkgs.localSystem = config.nixpkgs.localSystem; } ] ++ baseModules;
-          args = (config._module.args) // { modules = [ ]; };
-          specialArgs = { pkgs = scrubDerivations "pkgs" pkgs; };
-        };
-        scrubDerivations = namePrefix: pkgSet: mapAttrs
-          (name: value:
-            let wholeName = "${namePrefix}.${name}"; in
-            if isAttrs value then
-              scrubDerivations wholeName value
-              // (optionalAttrs (isDerivation value) { outPath = "\${${wholeName}}"; })
-            else value
-          )
-          pkgSet;
-      in scrubbedEval.options;
-  };
-
-  helpScript = pkgs.writeScriptBin "nixos-help"
-    ''
-      #! ${pkgs.runtimeShell} -e
-      # Finds first executable browser in a colon-separated list.
-      # (see how xdg-open defines BROWSER)
-      browser="$(
-        IFS=: ; for b in $BROWSER; do
-          [ -n "$(type -P "$b" || true)" ] && echo "$b" && break
-        done
-      )"
-      if [ -z "$browser" ]; then
-        browser="$(type -P xdg-open || true)"
-        if [ -z "$browser" ]; then
-          browser="$(type -P w3m || true)"
-          if [ -z "$browser" ]; then
-            echo "$0: unable to start a web browser; please set \$BROWSER"
-            exit 1
-          fi
-        fi
-      fi
-      exec "$browser" ${manual.manualHTMLIndex}
-    '';
-
-  desktopItem = pkgs.makeDesktopItem {
-    name = "nixos-manual";
-    desktopName = "NixOS Manual";
-    genericName = "View NixOS documentation in a web browser";
-    icon = "nix-snowflake";
-    exec = "${helpScript}/bin/nixos-help";
-    categories = "System";
-  };
-in
+let cfg = config.services.nixosManual; in
 
 {
 
   options = {
 
-    services.nixosManual.enable = mkOption {
-      type = types.bool;
-      default = true;
-      description = ''
-        Whether to build the NixOS manual pages.
-      '';
-    };
-
+    # TODO(@oxij): rename this to `.enable` eventually.
     services.nixosManual.showManual = mkOption {
       type = types.bool;
       default = false;
@@ -112,36 +41,28 @@ in
   };
 
 
-  config = mkIf cfg.enable {
-
-    system.build.manual = manual;
+  config = mkIf cfg.showManual {
 
-    environment.systemPackages = []
-      ++ optionals config.services.xserver.enable [ desktopItem pkgs.nixos-icons ]
-      ++ optional  config.documentation.man.enable manual.manpages
-      ++ optionals config.documentation.doc.enable [ manual.manualHTML helpScript ];
+    assertions = [{
+      assertion = config.documentation.nixos.enable;
+      message   = "Can't enable `service.nixosManual.showManual` without `documentation.nixos.enable`";
+    }];
 
-    boot.extraTTYs = mkIf cfg.showManual ["tty${toString cfg.ttyNumber}"];
+    boot.extraTTYs = [ "tty${toString cfg.ttyNumber}" ];
 
-    systemd.services = optionalAttrs cfg.showManual
-      { "nixos-manual" =
-        { description = "NixOS Manual";
-          wantedBy = [ "multi-user.target" ];
-          serviceConfig =
-            { ExecStart = "${cfg.browser} ${manual.manualHTMLIndex}";
-              StandardInput = "tty";
-              StandardOutput = "tty";
-              TTYPath = "/dev/tty${toString cfg.ttyNumber}";
-              TTYReset = true;
-              TTYVTDisallocate = true;
-              Restart = "always";
-            };
-        };
+    systemd.services."nixos-manual" = {
+      description = "NixOS Manual";
+      wantedBy = [ "multi-user.target" ];
+      serviceConfig = {
+        ExecStart = "${cfg.browser} ${config.system.build.manual.manualHTMLIndex}";
+        StandardInput = "tty";
+        StandardOutput = "tty";
+        TTYPath = "/dev/tty${toString cfg.ttyNumber}";
+        TTYReset = true;
+        TTYVTDisallocate = true;
+        Restart = "always";
       };
-
-      services.mingetty.helpLine = "\nRun `nixos-help` "
-        + lib.optionalString cfg.showManual "or press <Alt-F${toString cfg.ttyNumber}> "
-        + "for the NixOS manual.";
+    };
 
   };
 
diff --git a/nixos/tests/misc.nix b/nixos/tests/misc.nix
index b0bc1d083b1..6d72ac997f8 100644
--- a/nixos/tests/misc.nix
+++ b/nixos/tests/misc.nix
@@ -14,7 +14,7 @@ import ./make-test.nix ({ pkgs, ...} : rec {
     { swapDevices = mkOverride 0
         [ { device = "/root/swapfile"; size = 128; } ];
       environment.variables.EDITOR = mkOverride 0 "emacs";
-      services.nixosManual.enable = mkOverride 0 true;
+      documentation.nixos.enable = mkOverride 0 true;
       systemd.tmpfiles.rules = [ "d /tmp 1777 root root 10d" ];
       fileSystems = mkVMOverride { "/tmp2" =
         { fsType = "tmpfs";