Merge pull request #68897 from edolstra/master

Flake support

flake.nix

@@ -0,0 +1,50 @@
+# Experimental flake interface to Nixpkgs.
+# See https://github.com/NixOS/rfcs/pull/49 for details.
+{
+  edition = 201909;
+
+  description = "A collection of packages for the Nix package manager";
+
+  outputs = { self }:
+    let
+
+      jobs = import ./pkgs/top-level/release.nix {
+        nixpkgs = self;
+      };
+
+      lib = import ./lib;
+
+      systems = [ "x86_64-linux" "i686-linux" "x86_64-darwin" "aarch64-linux" ];
+
+      forAllSystems = f: lib.genAttrs systems (system: f system);
+
+    in
+    {
+      lib = lib // {
+        nixosSystem = { modules, ... } @ args:
+          import ./nixos/lib/eval-config.nix (args // {
+            modules = modules ++
+              [ { system.nixos.versionSuffix =
+                    ".${lib.substring 0 8 self.lastModified}.${self.shortRev or "dirty"}";
+                  system.nixos.revision = lib.mkIf (self ? rev) self.rev;
+                }
+              ];
+          });
+      };
+
+      checks.x86_64-linux.tarball = jobs.tarball;
+
+      htmlDocs = {
+        nixpkgsManual = jobs.manual;
+        nixosManual = (import ./nixos/release-small.nix {
+          nixpkgs = self;
+        }).nixos.manual.x86_64-linux;
+      };
+
+      legacyPackages = forAllSystems (system: import ./. { inherit system; });
+
+      nixosModules = {
+        notDetected = import ./nixos/modules/installer/scan/not-detected.nix;
+      };
+    };
+}

lib/tests/misc.nix

@@ -148,7 +148,7 @@ runTests {
             "${builtins.storeDir}/d945ibfx9x185xf04b890y4f9g3cbb63-python-2.7.11";
       in {
         storePath = isStorePath goodPath;
-        storePathDerivation = isStorePath (import ../.. {}).hello;
+        storePathDerivation = isStorePath (import ../.. { system = "x86_64-linux"; }).hello;
         storePathAppendix = isStorePath
           "${goodPath}/bin/python";
         nonAbsolute = isStorePath (concatStrings (tail (stringToCharacters goodPath)));

lib/tests/release.nix

@@ -2,7 +2,7 @@
 
 pkgs.runCommandNoCC "nixpkgs-lib-tests" {
   buildInputs = [ pkgs.nix (import ./check-eval.nix) ];
-  NIX_PATH="nixpkgs=${pkgs.path}";
+  NIX_PATH = "nixpkgs=${toString pkgs.path}";
 } ''
     datadir="${pkgs.nix}/share"
     export TEST_ROOT=$(pwd)/test-tmp

nixos/doc/manual/man-nixos-rebuild.xml

@@ -77,7 +77,14 @@
     <option>--builders</option> <replaceable>builder-spec</replaceable>
    </arg>
 
+   <sbr/>
+
+   <arg>
+    <option>--flake</option> <replaceable>flake-uri</replaceable>
+   </arg>
+
    <sbr />
+
    <arg>
     <group choice='req'>
     <arg choice='plain'>
@@ -129,14 +136,17 @@
   <title>Description</title>
 
   <para>
-   This command updates the system so that it corresponds to the configuration
-   specified in <filename>/etc/nixos/configuration.nix</filename>. Thus, every
-   time you modify <filename>/etc/nixos/configuration.nix</filename> or any
-   NixOS module, you must run <command>nixos-rebuild</command> to make the
-   changes take effect. It builds the new system in
-   <filename>/nix/store</filename>, runs its activation script, and stop and
-   (re)starts any system services if needed. Please note that user services need
-   to be started manually as they aren't detected by the activation script at the moment.
+   This command updates the system so that it corresponds to the
+   configuration specified in
+   <filename>/etc/nixos/configuration.nix</filename> or
+   <filename>/etc/nixos/flake.nix</filename>. Thus, every time you
+   modify the configuration or any other NixOS module, you must run
+   <command>nixos-rebuild</command> to make the changes take
+   effect. It builds the new system in
+   <filename>/nix/store</filename>, runs its activation script, and
+   stop and (re)starts any system services if needed. Please note that
+   user services need to be started manually as they aren't detected
+   by the activation script at the moment.
   </para>
 
   <para>
@@ -508,6 +518,24 @@
      </para>
     </listitem>
    </varlistentry>
+
+   <varlistentry>
+    <term>
+     <option>--flake</option> <replaceable>flake-uri</replaceable>[<replaceable>name</replaceable>]
+    </term>
+    <listitem>
+     <para>
+      Build the NixOS system from the specified flake. It defaults to
+      the directory containing the target of the symlink
+      <filename>/etc/nixos/flake.nix</filename>, if it exists. The
+      flake must contain an output named
+      <literal>nixosConfigurations.<replaceable>name</replaceable></literal>. If
+      <replaceable>name</replaceable> is omitted, it default to the
+      current host name.
+     </para>
+    </listitem>
+   </varlistentry>
+
   </variablelist>
 
   <para>
@@ -554,6 +582,21 @@
 
   <variablelist>
 
+   <varlistentry>
+    <term>
+     <filename>/etc/nixos/flake.nix</filename>
+    </term>
+    <listitem>
+     <para>
+      If this file exists, then <command>nixos-rebuild</command> will
+      use it as if the <option>--flake</option> option was given. This
+      file may be a symlink to a <filename>flake.nix</filename> in an
+      actual flake; thus <filename>/etc/nixos</filename> need not be a
+      flake.
+     </para>
+    </listitem>
+   </varlistentry>
+
    <varlistentry>
     <term>
      <filename>/run/current-system</filename>

nixos/doc/manual/man-nixos-version.xml

@@ -20,8 +20,14 @@
    <arg>
     <option>--revision</option>
    </arg>
+
+   <arg>
+    <option>--json</option>
+   </arg>
+
   </cmdsynopsis>
  </refsynopsisdiv>
+
  <refsection>
   <title>Description</title>
   <para>
@@ -84,12 +90,16 @@
    </variablelist>
   </para>
  </refsection>
+
  <refsection>
   <title>Options</title>
+
   <para>
    This command accepts the following options:
   </para>
+
   <variablelist>
+
    <varlistentry>
     <term>
      <option>--hash</option>
@@ -107,6 +117,21 @@
      </para>
     </listitem>
    </varlistentry>
+
+   <varlistentry>
+    <term>
+     <option>--json</option>
+    </term>
+    <listitem>
+     <para>
+      Print a JSON representation of the versions of NixOS and the
+      top-level configuration flake.
+     </para>
+    </listitem>
+   </varlistentry>
+
   </variablelist>
+
  </refsection>
+
 </refentry>

nixos/modules/installer/tools/nixos-rebuild.sh

@@ -3,6 +3,9 @@
 if [ -x "@shell@" ]; then export SHELL="@shell@"; fi;
 
 set -e
+set -o pipefail
+
+export PATH=@path@:$PATH
 
 showSyntax() {
     exec man nixos-rebuild
@@ -13,6 +16,7 @@ showSyntax() {
 # Parse the command line.
 origArgs=("$@")
 extraBuildFlags=()
+lockFlags=()
 action=
 buildNix=1
 fast=
@@ -58,7 +62,7 @@ while [ "$#" -gt 0 ]; do
         j="$1"; shift 1
         extraBuildFlags+=("$i" "$j")
         ;;
-      --show-trace|--keep-failed|-K|--keep-going|-k|--verbose|-v|-vv|-vvv|-vvvv|-vvvvv|--fallback|--repair|--no-build-output|-Q|-j*)
+      --show-trace|--keep-failed|-K|--keep-going|-k|--verbose|-v|-vv|-vvv|-vvvv|-vvvvv|--fallback|--repair|--no-build-output|-Q|-j*|-L|--refresh|--no-net)
         extraBuildFlags+=("$i")
         ;;
       --option)
@@ -93,6 +97,22 @@ while [ "$#" -gt 0 ]; do
       --use-remote-sudo)
         maybeSudo=(sudo --)
         ;;
+      --flake)
+        flake="$1"
+        shift 1
+        ;;
+      --recreate-lock-file|--no-update-lock-file|--no-write-lock-file|--no-registries|--commit-lock-file)
+        lockFlags+=("$i")
+        ;;
+      --update-input)
+        j="$1"; shift 1
+        lockFlags+=("$i" "$j")
+        ;;
+      --override-input)
+        j="$1"; shift 1
+        k="$1"; shift 1
+        lockFlags+=("$i" "$j" "$k")
+        ;;
       *)
         echo "$0: unknown option \`$i'"
         exit 1
@@ -202,7 +222,7 @@ fi
 
 
 # If ‘--upgrade’ is given, run ‘nix-channel --update nixos’.
-if [ -n "$upgrade" -a -z "$_NIXOS_REBUILD_REEXEC" ]; then
+if [[ -n $upgrade && -z $_NIXOS_REBUILD_REEXEC && -z $flake ]]; then
     nix-channel --update nixos
 
     # If there are other channels that contain a file called
@@ -225,8 +245,15 @@ if [ -z "$_NIXOS_REBUILD_REEXEC" ]; then
     export PATH=@nix@/bin:$PATH
 fi
 
+# Use /etc/nixos/flake.nix if it exists. It can be a symlink to the
+# actual flake.
+if [[ -z $flake && -e /etc/nixos/flake.nix ]]; then
+    flake="$(dirname "$(readlink -f /etc/nixos/flake.nix)")"
+fi
+
 # Re-execute nixos-rebuild from the Nixpkgs tree.
-if [ -z "$_NIXOS_REBUILD_REEXEC" -a -n "$canRun" -a -z "$fast" ]; then
+# FIXME: get nixos-rebuild from $flake.
+if [[ -z $_NIXOS_REBUILD_REEXEC && -n $canRun && -z $fast && -z $flake ]]; then
     if p=$(nix-build --no-out-link --expr 'with import <nixpkgs/nixos> {}; config.system.build.nixos-rebuild' "${extraBuildFlags[@]}"); then
         export _NIXOS_REBUILD_REEXEC=1
         exec $p/bin/nixos-rebuild "${origArgs[@]}"
@@ -234,10 +261,37 @@ if [ -z "$_NIXOS_REBUILD_REEXEC" -a -n "$canRun" -a -z "$fast" ]; then
     fi
 fi
 
+# For convenience, use the hostname as the default configuration to
+# build from the flake.
+if [[ -n $flake ]]; then
+    if [[ $flake =~ ^(.*)\#([^\#\"]*)$ ]]; then
+       flake="${BASH_REMATCH[1]}"
+       flakeAttr="${BASH_REMATCH[2]}"
+    fi
+    if [[ -z $flakeAttr ]]; then
+        read -r hostname < /proc/sys/kernel/hostname
+        if [[ -z $hostname ]]; then
+            hostname=default
+        fi
+        flakeAttr="nixosConfigurations.\"$hostname\""
+    else
+        flakeAttr="nixosConfigurations.\"$flakeAttr\""
+    fi
+fi
+
+# Resolve the flake.
+if [[ -n $flake ]]; then
+    flake=$(nix flake info --json "${extraBuildFlags[@]}" "${lockFlags[@]}" -- "$flake" | jq -r .url)
+fi
+
 # Find configuration.nix and open editor instead of building.
 if [ "$action" = edit ]; then
+    if [[ -z $flake ]]; then
         NIXOS_CONFIG=${NIXOS_CONFIG:-$(nix-instantiate --find-file nixos-config)}
         exec "${EDITOR:-nano}" "$NIXOS_CONFIG"
+    else
+        exec nix edit "${lockFlags[@]}" -- "$flake#$flakeAttr"
+    fi
     exit 1
 fi
 
@@ -296,7 +350,7 @@ prebuiltNix() {
 
 remotePATH=
 
-if [ -n "$buildNix" ]; then
+if [[ -n $buildNix && -z $flake ]]; then
     echo "building Nix..." >&2
     nixDrv=
     if ! nixDrv="$(nix-instantiate '<nixpkgs/nixos>' --add-root $tmpDir/nix.drv --indirect -A config.nix.package.out "${extraBuildFlags[@]}")"; then
@@ -337,7 +391,7 @@ fi
 
 # Update the version suffix if we're building from Git (so that
 # nixos-version shows something useful).
-if [ -n "$canRun" ]; then
+if [[ -n $canRun && -z $flake ]]; then
     if nixpkgs=$(nix-instantiate --find-file nixpkgs "${extraBuildFlags[@]}"); then
         suffix=$($SHELL $nixpkgs/nixos/modules/installer/tools/get-version-suffix "${extraBuildFlags[@]}" || true)
         if [ -n "$suffix" ]; then
@@ -358,15 +412,37 @@ fi
 if [ -z "$rollback" ]; then
     echo "building the system configuration..." >&2
     if [ "$action" = switch -o "$action" = boot ]; then
+        if [[ -z $flake ]]; then
             pathToConfig="$(nixBuild '<nixpkgs/nixos>' --no-out-link -A system "${extraBuildFlags[@]}")"
+        else
+            outLink=$tmpDir/result
+            nix build "$flake#$flakeAttr.config.system.build.toplevel" \
+              "${extraBuildFlags[@]}" "${lockFlags[@]}" --out-link $outLink
+            pathToConfig="$(readlink -f $outLink)"
+        fi
         copyToTarget "$pathToConfig"
         targetHostCmd nix-env -p "$profile" --set "$pathToConfig"
     elif [ "$action" = test -o "$action" = build -o "$action" = dry-build -o "$action" = dry-activate ]; then
+        if [[ -z $flake ]]; then
             pathToConfig="$(nixBuild '<nixpkgs/nixos>' -A system -k "${extraBuildFlags[@]}")"
+        else
+            nix build "$flake#$flakeAttr.config.system.build.toplevel" "${extraBuildFlags[@]}" "${lockFlags[@]}"
+            pathToConfig="$(readlink -f ./result)"
+        fi
     elif [ "$action" = build-vm ]; then
+        if [[ -z $flake ]]; then
             pathToConfig="$(nixBuild '<nixpkgs/nixos>' -A vm -k "${extraBuildFlags[@]}")"
+        else
+            echo "$0: 'build-vm' is not supported with '--flake'" >&2
+            exit 1
+        fi
     elif [ "$action" = build-vm-with-bootloader ]; then
+        if [[ -z $flake ]]; then
             pathToConfig="$(nixBuild '<nixpkgs/nixos>' -A vmWithBootLoader -k "${extraBuildFlags[@]}")"
+        else
+            echo "$0: 'build-vm-with-bootloader' is not supported with '--flake'" >&2
+            exit 1
+        fi
     else
         showSyntax
     fi

nixos/modules/installer/tools/nixos-version.sh

@@ -6,8 +6,17 @@ case "$1" in
     exit 1
     ;;
   --hash|--revision)
+    if ! [[ @revision@ =~ ^[0-9a-f]+$ ]]; then
+      echo "$0: Nixpkgs commit hash is unknown"
+      exit 1
+    fi
     echo "@revision@"
     ;;
+  --json)
+    cat <<EOF
+@json@
+EOF
+    ;;
   *)
     echo "@version@ (@codeName@)"
     ;;

nixos/modules/installer/tools/tools.nix

@@ -31,6 +31,7 @@ let
       nix = config.nix.package.out;
       nix_x86_64_linux = fallback.x86_64-linux;
       nix_i686_linux = fallback.i686-linux;
+      path = makeBinPath [ pkgs.jq ];
     };
 
   nixos-generate-config = makeProg {
@@ -47,6 +48,14 @@ let
     name = "nixos-version";
     src = ./nixos-version.sh;
     inherit (config.system.nixos) version codeName revision;
+    inherit (config.system) configurationRevision;
+    json = builtins.toJSON ({
+      nixosVersion = config.system.nixos.version;
+    } // optionalAttrs (config.system.nixos.revision != null) {
+      nixpkgsRevision = config.system.nixos.revision;
+    } // optionalAttrs (config.system.configurationRevision != null) {
+      configurationRevision = config.system.configurationRevision;
+    });
   };
 
   nixos-enter = makeProg {

nixos/modules/misc/version.nix

@@ -42,8 +42,8 @@ in
 
     nixos.revision = mkOption {
       internal = true;
-      type = types.str;
-      default = trivial.revisionWithDefault "master";
+      type = types.nullOr types.str;
+      default = trivial.revisionWithDefault null;
       description = "The Git revision from which this NixOS configuration was built.";
     };
 
@@ -84,6 +84,12 @@ in
       description = "Default NixOS channel to which the root user is subscribed.";
     };
 
+    configurationRevision = mkOption {
+      type = types.nullOr types.str;
+      default = null;
+      description = "The Git revision of the top-level flake from which this configuration was built.";
+    };
+
   };
 
   config = {

pkgs/tools/virtualization/nixos-container/nixos-container.pl

@@ -22,13 +22,27 @@ $ENV{"NIXOS_CONFIG"} = "";
 sub showHelp {
     print <<EOF;
 Usage: nixos-container list
-       nixos-container create <container-name> [--nixos-path <path>] [--system-path <path>] [--config-file <path>] [--config <string>] [--ensure-unique-name] [--auto-start] [--bridge <iface>] [--port <port>] [--host-address <string>] [--local-address <string>]
+       nixos-container create <container-name>
+         [--nixos-path <path>]
+         [--system-path <path>]
+         [--config <string>]
+         [--config-file <path>]
+         [--flake <flakeref>]
+         [--ensure-unique-name]
+         [--auto-start]
+         [--bridge <iface>]
+         [--port <port>]
+         [--host-address <string>]
+         [--local-address <string>]
        nixos-container destroy <container-name>
        nixos-container start <container-name>
        nixos-container stop <container-name>
        nixos-container terminate <container-name>
        nixos-container status <container-name>
-       nixos-container update <container-name> [--config <string>] [--config-file <path>]
+       nixos-container update <container-name>
+         [--config <string>]
+         [--config-file <path>]
+         [--flake <flakeref>]
        nixos-container login <container-name>
        nixos-container root-login <container-name>
        nixos-container run <container-name> -- args...
@@ -49,6 +63,8 @@ my $signal;
 my $configFile;
 my $hostAddress;
 my $localAddress;
+my $flake;
+my $flakeAttr = "container";
 
 GetOptions(
     "help" => sub { showHelp() },
@@ -63,6 +79,7 @@ GetOptions(
     "config-file=s" => \$configFile,
     "host-address=s" => \$hostAddress,
     "local-address=s" => \$localAddress,
+    "flake=s" => \$flake,
     ) or exit 1;
 
 if (defined $hostAddress and !defined $localAddress or defined $localAddress and !defined $hostAddress) {
@@ -76,6 +93,11 @@ if (defined $configFile and defined $extraConfig) {
         "Please define on or the other, but not both";
 }
 
+if (defined $flake && $flake =~ /^(.*)#([^#"]+)$/) {
+    $flake = $1;
+    $flakeAttr = $2;
+}
+
 # Execute the selected action.
 
 mkpath("/etc/containers", 0, 0755);
@@ -97,8 +119,6 @@ sub writeNixOSConfig {
 
     my $localExtraConfig = "";
 
-
-
     if ($extraConfig) {
         $localExtraConfig = $extraConfig
     } elsif ($configFile) {
@@ -121,6 +141,14 @@ EOF
     write_file($nixosConfigFile, $nixosConfig);
 }
 
+sub buildFlake {
+    system("nix", "build", "-o", "$systemPath.tmp", "--",
+           "$flake#nixosConfigurations.\"$flakeAttr\".config.system.build.toplevel") == 0
+        or die "$0: failed to build container from flake '$flake'\n";
+    $systemPath = readlink("$systemPath.tmp") or die;
+    unlink("$systemPath.tmp");
+}
+
 if ($action eq "create") {
     # Acquire an exclusive lock to prevent races with other
     # invocations of ‘nixos-container create’.
@@ -176,6 +204,7 @@ if ($action eq "create") {
     push @conf, "HOST_BRIDGE=$bridge\n";
     push @conf, "HOST_PORT=$port\n";
     push @conf, "AUTO_START=$autoStart\n";
+    push @conf, "FLAKE=$flake\n" if defined $flake;
     write_file($confFile, \@conf);
 
     close($lock);
@@ -191,6 +220,10 @@ if ($action eq "create") {
     mkpath($profileDir, 0, 0755);
 
     # Build/set the initial configuration.
+    if (defined $flake) {
+        buildFlake();
+    }
+
     if (defined $systemPath) {
         system("nix-env", "-p", "$profileDir/system", "--set", $systemPath) == 0
             or die "$0: failed to set initial container configuration\n";
@@ -326,6 +359,21 @@ elsif ($action eq "status") {
 }
 
 elsif ($action eq "update") {
+
+    # Unless overriden on the command line, rebuild the flake recorded
+    # in the container config file. FIXME: read the container config
+    # in a more sensible way.
+    if (!defined $flake && !defined $configFile && !defined $extraConfig) {
+        my $s = read_file($confFile);
+        $s =~ /^FLAKE=(.*)$/m;
+        $flake = $1;
+    }
+
+    if (defined $flake) {
+        buildFlake();
+        system("nix-env", "-p", "$profileDir/system", "--set", $systemPath) == 0
+            or die "$0: failed to set container configuration\n";
+    } else {
         my $nixosConfigFile = "$root/etc/nixos/configuration.nix";
 
         # FIXME: may want to be more careful about clobbering the existing
@@ -339,6 +387,7 @@ elsif ($action eq "update") {
                "-I", "nixos-config=$nixosConfigFile", "-f", "<nixpkgs/nixos>",
                "--set", "-A", "system") == 0
             or die "$0: failed to build container configuration\n";
+    }
 
     if (isContainerRunning) {
         print STDERR "reloading container...\n";

pkgs/top-level/make-tarball.nix

@@ -17,7 +17,10 @@ releaseTools.sourceTarball {
 
   inherit officialRelease;
   version = pkgs.lib.fileContents ../../.version;
-  versionSuffix = "pre${toString nixpkgs.revCount}.${nixpkgs.shortRev}";
+  versionSuffix = "pre${
+    if nixpkgs ? lastModified
+    then builtins.substring 0 8 nixpkgs.lastModified
+    else toString nixpkgs.revCount}.${nixpkgs.shortRev or "dirty"}";
 
   buildInputs = [ nix.out jq lib-tests ];
 
@@ -25,7 +28,7 @@ releaseTools.sourceTarball {
     eval "$preConfigure"
     releaseName=nixpkgs-$VERSION$VERSION_SUFFIX
     echo -n $VERSION_SUFFIX > .version-suffix
-    echo -n ${nixpkgs.rev or nixpkgs.shortRev} > .git-revision
+    echo -n ${nixpkgs.rev or nixpkgs.shortRev or "dirty"} > .git-revision
     echo "release name is $releaseName"
     echo "git-revision is $(cat .git-revision)"
   '';