* The CD is now a true live CD: you can run Nix operations in it

thanks to unionfs.  For instance, nix-env and nixos-rebuild work.
  The tricky part was to build a Nix database (in the tmpfs/unionfs)
  which is now necessary to prevent store paths on the CD from being
  deleted right away because they otherwise wouldn't be valid.
  
* nixos-install: use the /etc/nixos/configuration.nix from the target
  file system (don't copy it anymore).  Since the user is supposed to
  mount the target file system on /mnt anyway, we may as well require
  that configuration.nix is placed in /mnt/etc/nixos.  This also makes
  upgrading / reinstalling much easier, since it will automatically
  use the right configuration.nix.

svn path=/nixos/trunk/; revision=10399

configuration/rescue-cd.nix

@@ -36,14 +36,18 @@ rec {
 
       extraJobs = [
         # Unpack the NixOS/Nixpkgs sources to /etc/nixos.
+        # !!! run this synchronously
         { name = "unpack-sources";
           job = "
             start on startup
             script
               export PATH=${pkgs.gnutar}/bin:${pkgs.bzip2}/bin:$PATH
+
+              ${system.nix}/bin/nix-store --load-db < /nix-path-registration
+
               mkdir -p /etc/nixos/nixos
-              tar xjf /nixos.tar.bz2 -C /etc/nixos/nixos
-              tar xjf /nixpkgs.tar.bz2 -C /etc/nixos
+              tar xjf /install/nixos.tar.bz2 -C /etc/nixos/nixos
+              tar xjf /install/nixpkgs.tar.bz2 -C /etc/nixos
               mv /etc/nixos/nixpkgs-* /etc/nixos/nixpkgs
               ln -sfn ../nixpkgs/pkgs /etc/nixos/nixos/pkgs
               chown -R root.root /etc/nixos
@@ -66,6 +70,7 @@ rec {
         { name = "rogue";
           job = "
             env HOME=/root
+            chdir /root
             start on udev
             stop on shutdown
             respawn ${pkgs.rogue}/bin/rogue < /dev/tty8 > /dev/tty8 2>&1
@@ -214,10 +219,10 @@ rec {
         target = "boot/background.xpm.gz";
       }
       { source = nixosTarball + "/" + nixosTarball.tarName;
-        target = "/" + nixosTarball.tarName;
+        target = "/install/" + nixosTarball.tarName;
       }
       { source = nixpkgsTarball;
-        target = "/nixpkgs.tar.bz2";
+        target = "/install/nixpkgs.tar.bz2";
       }
       { source = pkgs.writeText "label" "";
         target = "/${configuration.boot.rootLabel}";

etc/profile.sh

@@ -73,7 +73,7 @@ if test ! -e $HOME/.nix-defexpr -o -L $HOME/.nix-defexpr; then
     echo "creating $HOME/.nix-defexpr" >&2
     rm -f $HOME/.nix-defexpr
     mkdir $HOME/.nix-defexpr
-    ln -s /etc/nixos/install-source.nix $HOME/.nix-defexpr/nixpkgs_sys
+    ln -s /etc/nixos/nixpkgs $HOME/.nix-defexpr/nixpkgs_sys
     ln -s /etc/nixos/nixos $HOME/.nix-defexpr/nixos
     if test "$USER" != root; then
         ln -s /nix/var/nix/gcroots/per-user/root/channels $HOME/.nix-defexpr/channels_root

helpers/make-iso9660-image.sh

@@ -39,8 +39,8 @@ done
 
 
 # Also put a nix-pull manifest of the closures on the CD.
-printManifest=1 perl $pathsFromGraph closure-* > MANIFEST
-echo "MANIFEST=MANIFEST" >> pathlist
+printRegistration=1 perl $pathsFromGraph closure-* > nix-path-registration
+echo "nix-path-registration=nix-path-registration" >> pathlist
 
 
 # Add symlinks to the top-level store objects.

helpers/paths-from-graph.pl

@@ -47,6 +47,20 @@ if ($ENV{"printManifest"} eq "1") {
     }
 }
 
+elsif ($ENV{"printRegistration"} eq "1") {
+    # This is the format used by `nix-store --register-validity
+    # --hash-given' / `nix-store --load-db'.
+    foreach my $storePath (sort (keys %storePaths)) {
+        print "$storePath\n";
+        print "0000000000000000000000000000000000000000000000000000000000000000\n"; # !!! fix
+        print "\n"; # don't care about preserving the deriver
+        print scalar(@{$refs{$storePath}}), "\n";
+        foreach my $ref (@{$refs{$storePath}}) {
+            print "$ref\n";
+        }
+    }
+}
+
 else {
     foreach my $storePath (sort (keys %storePaths)) {
         print "$storePath\n";

installer/nixos-checkout.sh

@@ -29,8 +29,7 @@ fi
 svn co https://svn.cs.uu.nl:12443/repos/trace/nixos/trunk nixos
 svn co https://svn.cs.uu.nl:12443/repos/trace/nixpkgs/trunk nixpkgs
 svn co https://svn.cs.uu.nl:12443/repos/trace/services/trunk services
-ln -sfn ../services nixos/services
 
-# A few symlink.
+# Add a few required symlink.
+ln -sfn ../services nixos/services
 ln -sfn ../nixpkgs/pkgs nixos/pkgs
-ln -sfn nixpkgs/pkgs/top-level/all-packages.nix install-source.nix

installer/nixos-install.sh

@@ -19,6 +19,7 @@ if test -z "$NIXOS"; then
     NIXOS=/etc/nixos/nixos
 fi
 
+# NIXOS_CONFIG is interpreted relative to $mountPoint.
 if test -z "$NIXOS_CONFIG"; then
     NIXOS_CONFIG=/etc/nixos/configuration.nix
 fi
@@ -38,14 +39,13 @@ if ! test -e "$NIXOS"; then
     exit 1
 fi
     
-if ! test -e "$NIXOS_CONFIG"; then
-    echo "configuration file $NIXOS_CONFIG doesn't exist"
+if ! test -e "$mountPoint/$NIXOS_CONFIG"; then
+    echo "configuration file $mountPoint/$NIXOS_CONFIG doesn't exist"
     exit 1
 fi
     
 
 NIXOS=$(readlink -f "$NIXOS")
-NIXOS_CONFIG=$(readlink -f "$NIXOS_CONFIG")
 
 
 # Mount some stuff in the target root directory.
@@ -142,22 +142,10 @@ echo "building the system configuration..."
 chroot $mountPoint @nix@/bin/nix-env \
     -p /nix/var/nix/profiles/system \
     -f "/mnt$NIXOS/system/system.nix" \
-    --arg configuration "import /mnt$NIXOS_CONFIG" \
+    --arg configuration "import $NIXOS_CONFIG" \
     --set -A system
 
 
-# Copy the configuration to /etc/nixos.
-backupTimestamp=$(date "+%Y%m%d%H%M%S")
-targetConfig=$mountPoint/etc/nixos/configuration.nix
-mkdir -p $(dirname $targetConfig)
-if test -e $targetConfig -o -L $targetConfig; then
-    cp -f $targetConfig $targetConfig.backup-$backupTimestamp
-fi
-if test "$NIXOS_CONFIG" != "$targetConfig"; then
-    cp -f $NIXOS_CONFIG $targetConfig
-fi
-
-
 # Make a backup of the old NixOS/Nixpkgs sources.
 echo "copying NixOS/Nixpkgs sources to /etc/nixos...."
 
@@ -177,7 +165,6 @@ cp -prd $NIXOS $targetNixos
 if test -e /etc/nixos/nixpkgs; then
     cp -prd /etc/nixos/nixpkgs $targetNixpkgs
 fi
-ln -sfn nixpkgs/pkgs/top-level/all-packages.nix $mountPoint/etc/nixos/install-source.nix
 
 
 # Grub needs a mtab.

system/activate-configuration.sh

@@ -155,7 +155,10 @@ fi
 
 
 # Make this configuration the current configuration.
-ln -sfn "$systemConfig" /var/run/current-system
+# The readlink is there to ensure that when $systemConfig = /system
+# (which is a symlink to the store), /var/run/current-system is still
+# used as a garbage collection root.
+ln -sfn "$(readlink -f "$systemConfig")" /var/run/current-system
 
 
 # Prevent the current configuration from being garbage-collected.