* $HYDRA_DATA environment variable.

src/Hydra/lib/Hydra.pm

@@ -2,6 +2,7 @@ package Hydra;
 
 use strict;
 use warnings;
+use Hydra::Helper::Nix;
 
 use Catalyst::Runtime '5.70';
 
@@ -20,8 +21,11 @@ our $VERSION = '0.01';
 
 __PACKAGE__->config(
     name => 'Hydra',
-    default_view => "TT"
-    );
+    default_view => "TT",
+    session => {
+        storage => getHydraPath . "/session_data"
+    }
+);
 
 __PACKAGE__->setup();
 

src/Hydra/lib/Hydra/Controller/Root.pm

@@ -751,7 +751,7 @@ sub closure :Local {
 
     return error($c, "Product is not a Nix build.") if $product->type ne "nix-build";
 
-    return error($c, "Path " . $product->path . " is no longer available.") unless Hydra::Helper::Nix::isValidPath($product->path);
+    return error($c, "Path " . $product->path . " is no longer available.") unless isValidPath($product->path);
 
     $c->stash->{current_view} = 'Hydra::View::NixClosure';
     $c->stash->{storePath} = $product->path;

src/Hydra/lib/Hydra/Helper/Nix.pm

@@ -1,14 +1,39 @@
 package Hydra::Helper::Nix;
 
 use strict;
+use Exporter;
+
+our @ISA = qw(Exporter);
+our @EXPORT = qw(isValidPath getHydraPath getHydraDBPath openHydraDB);
 
 
 sub isValidPath {
     my $path = shift;
     $SIG{CHLD} = 'DEFAULT'; # !!! work around system() failing if SIGCHLD is ignored
-    return system("nix-store --check-validity $path") == 0;
+    return system("nix-store --check-validity $path 2> /dev/null") == 0;
+}
+
+
+sub getHydraPath {
+    my $dir = $ENV{HYDRA_DATA};
+    die "The HYDRA_DATA environment variable is not set!\n" unless defined $dir;
+    die "The HYDRA_DATA directory does not exist!\n" unless -d $dir;
+    return $dir;
+}
+
+
+sub getHydraDBPath {
+    my $path = getHydraPath . '/hydra.sqlite';
+    die "The Hydra database ($path) not exist!\n" unless -f $path;
+    return "dbi:SQLite:$path";
+}
+
+
+sub openHydraDB {
+    my $db = Hydra::Schema->connect(getHydraDBPath, "", "", {});
+    $db->storage->dbh->do("PRAGMA synchronous = OFF;");
+    return $db;
 }
 
 
 1;
-

src/Hydra/lib/Hydra/Model/DB.pm

@@ -2,13 +2,11 @@ package Hydra::Model::DB;
 
 use strict;
 use base 'Catalyst::Model::DBIC::Schema';
+use Hydra::Helper::Nix;
 
 __PACKAGE__->config(
     schema_class => 'Hydra::Schema',
-    connect_info => [
-        'dbi:SQLite:../hydra.sqlite',
-        
-    ],
+    connect_info => [getHydraDBPath],
 );
 
 =head1 NAME