Bug 302876: Database Version-Checking needs to be more modular and more generic

Patch By Max Kanat-Alexander <mkanat@bugzilla.org> r=wicked, a=myk

5 files changed, 65 insertions, 66 deletions

diff --git a/Bugzilla/Constants.pm b/Bugzilla/Constants.pm
index aed574f67..0c451c8c3 100644
--- a/Bugzilla/Constants.pm
+++ b/Bugzilla/Constants.pm
@@ -101,6 +101,8 @@ use base qw(Exporter);
     FIELD_TYPE_FREETEXT
 
     BUG_STATE_OPEN
+
+    DB_MODULE
 );
 
 @Bugzilla::Constants::EXPORT_OK = qw(contenttypes);
@@ -277,3 +279,13 @@ use constant BUG_STATE_OPEN => ('NEW', 'REOPENED', 'ASSIGNED',
                                 'UNCONFIRMED');
 
 1;
+
+# Data about what we require for different databases.
+use constant DB_MODULE => {
+    'mysql' => {db => 'Bugzilla::DB::Mysql', db_version => '4.0.14',
+                dbd => 'DBD::mysql', dbd_version => '2.9003',
+                name => 'MySQL'},
+    'pg'    => {db => 'Bugzilla::DB::Pg', db_version => '8.00.0000',
+                dbd => 'DBD::Pg', dbd_version => '1.45',
+                name => 'PostgreSQL'},
+};
diff --git a/Bugzilla/DB.pm b/Bugzilla/DB.pm
index 127218843..4a0099db4 100644
--- a/Bugzilla/DB.pm
+++ b/Bugzilla/DB.pm
@@ -48,6 +48,7 @@ use base qw(Exporter DBI::db);
 Exporter::export_ok_tags('deprecated');
 
 use Bugzilla::Config qw(:DEFAULT :db);
+use Bugzilla::Constants;
 use Bugzilla::Util;
 use Bugzilla::Error;
 use Bugzilla::DB::Schema;
@@ -164,14 +165,11 @@ sub connect_main {
 sub _connect {
     my ($driver, $host, $dbname, $port, $sock, $user, $pass) = @_;
 
-    # DB specific module have the same name as DB driver, here we
-    # just make sure we are not case sensitive
-    (my $db_module = $driver) =~ s/(\w+)/\u\L$1/g;
-    my $pkg_module = "Bugzilla::DB::" . $db_module;
+    my $pkg_module = DB_MODULE->{lc($driver)}->{db};
 
     # do the actual import
     eval ("require $pkg_module")
-        || die ("'$db_module' is not a valid choice for \$db_driver in "
+        || die ("'$driver' is not a valid choice for \$db_driver in "
                 . " localconfig: " . $@);
 
     # instantiate the correct DB specific module
@@ -622,8 +620,9 @@ sub bz_rename_column {
 sub _bz_schema {
     my ($self) = @_;
     return $self->{private_bz_schema} if exists $self->{private_bz_schema};
-    $self->{private_bz_schema} = 
-        Bugzilla::DB::Schema->new($self->MODULE_NAME);
+    my @module_parts = split('::', ref $self);
+    my $module_name  = pop @module_parts;
+    $self->{private_bz_schema} = Bugzilla::DB::Schema->new($module_name);
     return $self->{private_bz_schema};
 }
 
@@ -989,28 +988,6 @@ constants are required to be subroutines or "use constant" variables.
 The C<\%attr> argument that must be passed to bind_param in order to 
 correctly escape a C<LONGBLOB> type.
 
-=item C<REQUIRED_VERSION>
-
-This is the minimum required version of the database server that the
-Bugzilla::DB subclass requires. It should be in a format suitable for
-passing to vers_cmp during installation.
-
-=item C<PROGRAM_NAME>
-
-The human-readable name of this database. For example, for MySQL, this
-would be 'MySQL.' You should not depend on this variable to know what
-type of database you are running on; this is intended merely for displaying
-to the admin to let them know what DB they're running.
-
-=item C<MODULE_NAME>
-
-The name of the Bugzilla::DB module that we are. For example, for the MySQL
-Bugzilla::DB module, this would be "Mysql." For PostgreSQL it would be "Pg."
-
-=item C<DBD_VERSION>
-
-The minimum version of the DBD module that we require for this database.
-
 =back
 
 
@@ -1559,4 +1536,6 @@ PopGlobalSQLState
 
 L<DBI>
 
+L<Bugzilla::Constants> - The C<DB_MODULE> constant.
+
 =cut
diff --git a/Bugzilla/DB/Mysql.pm b/Bugzilla/DB/Mysql.pm
index e03fbc910..9493fb099 100644
--- a/Bugzilla/DB/Mysql.pm
+++ b/Bugzilla/DB/Mysql.pm
@@ -49,11 +49,6 @@ use Bugzilla::Error;
 # This module extends the DB interface via inheritance
 use base qw(Bugzilla::DB);
 
-use constant REQUIRED_VERSION => '4.0.14';
-use constant PROGRAM_NAME => 'MySQL';
-use constant MODULE_NAME  => 'Mysql';
-use constant DBD_VERSION  => '2.9003';
-
 sub new {
     my ($class, $user, $pass, $host, $dbname, $port, $sock) = @_;
 
diff --git a/Bugzilla/DB/Pg.pm b/Bugzilla/DB/Pg.pm
index 5162466c5..7bf64ab9d 100644
--- a/Bugzilla/DB/Pg.pm
+++ b/Bugzilla/DB/Pg.pm
@@ -50,10 +50,6 @@ use DBD::Pg;
 use base qw(Bugzilla::DB);
 
 use constant BLOB_TYPE => { pg_type => DBD::Pg::PG_BYTEA };
-use constant REQUIRED_VERSION => '8.00.0000';
-use constant PROGRAM_NAME => 'PostgreSQL';
-use constant MODULE_NAME  => 'Pg';
-use constant DBD_VERSION  => '1.45';
 
 sub new {
     my ($class, $user, $pass, $host, $dbname, $port) = @_;
diff --git a/checksetup.pl b/checksetup.pl
index a2564f0a6..cde8b4945 100755
--- a/checksetup.pl
+++ b/checksetup.pl
@@ -376,6 +376,17 @@ foreach my $module (@{$modules}) {
     }
 }
 
+print ("\nYou need one of the following DBD modules installed, depending on\n"
+      . "which database you are using with Bugzilla:\n") unless $silent;
+
+my $have_one_dbd = 0;
+my $db_modules = DB_MODULE;
+foreach my $db (keys %$db_modules) {
+    if (have_vers($db_modules->{$db}->{dbd}, $db_modules->{$db}->{dbd_version})) {
+        $have_one_dbd = 1;
+    }
+}
+
 print "\nThe following Perl modules are optional:\n" unless $silent;
 my $gd          = have_vers("GD","1.20");
 my $chartbase   = have_vers("Chart::Base","1.0");
@@ -433,8 +444,23 @@ if (!$patchreader && !$silent) {
     print "PatchReader: " . install_command("PatchReader") . "\n";
 }
 
-if (%missing) {
+if (!$have_one_dbd) {
     print "\n\n";
+    print "Bugzilla requires that at least one DBD module be installed in\n",
+          "order to access a database. You can install the correct one by\n",
+          "picking the command listed below for your database:\n";
+
+    foreach my $db (keys %$db_modules) {
+        print "   " . $db_modules->{$db}->{name} . ": "
+              . install_command($db_modules->{$db}->{dbd}) . "\n";
+        print "   Minimum version required: " 
+              . $db_modules->{$db}->{dbd_version} . "\n";
+    }
+    print "\n";
+}
+
+if (%missing) {
+    print "\n";
     print "Bugzilla requires some Perl modules which are either missing from\n",
           "your system, or the version on your system is too old.\n",
           "They can be installed by running (as $::root) the following:\n";
@@ -445,9 +471,10 @@ if (%missing) {
         }
     }
     print "\n";
-    exit;
 }
 
+exit if (%missing || !$have_one_dbd);
+
 }
 }
 
@@ -1487,37 +1514,27 @@ $::ENV{'PATH'} = $origPath;
 # Check if we have access to the --DATABASE--
 #
 
-# No need to "use" this here.  It should already be loaded from the
-# version-checking routines above, and this file won't even compile if
-# DBI isn't installed so the user gets nasty errors instead of our
-# pretty one saying they need to install it. -- justdave@syndicomm.com
-#use DBI;
-
 if ($my_db_check) {
-    # Do we have the database itself?
-
-    # Unfortunately, $my_db_driver doesn't map perfectly between DBD
-    # and Bugzilla::DB. We need to fix the case a bit.
-    (my $dbd_name = trim($my_db_driver)) =~ s/(\w+)/\u\L$1/g;
-    # And MySQL is special, because it's all lowercase in DBD.
-    $dbd_name = 'mysql' if $dbd_name eq 'Mysql';
-
-    my $dbd = "DBD::$dbd_name";
-    unless (eval("require $dbd")) {
-        print "Bugzilla requires that perl's $dbd be installed.\n"
-              . "To install this module, you can do:\n "
-              . "   " . install_command($dbd) . "\n";
-        exit;
+    # Only certain values are allowed for $db_driver.
+    if (!exists DB_MODULE->{lc($my_db_driver)}) {
+        die "$my_db_driver is not a valid choice for \$db_driver in",
+            " localconfig";
     }
 
-    my $dbh = Bugzilla::DB::connect_main("no database connection");
-    my $sql_want = $dbh->REQUIRED_VERSION;
-    my $sql_server = $dbh->PROGRAM_NAME;
-    my $dbd_ver = $dbh->DBD_VERSION;
-    unless (have_vers($dbd, $dbd_ver)) {
-        die "Bugzilla requires at least version $dbd_ver of $dbd.";
+    # Check the existence and version of the DBD that we need.
+    my $actual_dbd     = DB_MODULE->{lc($my_db_driver)}->{dbd};
+    my $actual_dbd_ver = DB_MODULE->{lc($my_db_driver)}->{dbd_version};
+    my $sql_server     = DB_MODULE->{lc($my_db_driver)}->{name};
+    my $sql_want       = DB_MODULE->{lc($my_db_driver)}->{db_version};
+    unless (have_vers($actual_dbd, $actual_dbd_ver)) {
+        print "For $sql_server, Bugzilla requires that perl's"
+              . " $actual_dbd be installed.\nTo install this module,"
+              . " you can do:\n   " . install_command($actual_dbd) . "\n";
+        exit;
     }
 
+    # And now check the version of the database server itself.
+    my $dbh = Bugzilla::DB::connect_main("no database connection");
     printf("Checking for %15s %-9s ", $sql_server, "(v$sql_want)") unless $silent;
     my $sql_vers = $dbh->bz_server_version;