1 package DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator;
4 # ABSTRACT: Manage your SQL and Perl migrations in nicely laid out directories
7 use Carp qw( carp croak );
8 use DBIx::Class::DeploymentHandler::LogImporter qw(:log :dlog);
14 require SQL::Translator::Diff;
16 require DBIx::Class::Storage; # loaded for type constraint
17 use DBIx::Class::DeploymentHandler::Types;
19 use File::Path 'mkpath';
20 use File::Spec::Functions;
22 with 'DBIx::Class::DeploymentHandler::HandlesDeploy';
30 has force_overwrite => (
42 isa => 'DBIx::Class::Storage',
49 my $s = $self->schema->storage;
50 $s->_determine_driver;
54 has sql_translator_args => (
57 default => sub { {} },
59 has script_directory => (
68 isa => 'DBIx::Class::DeploymentHandler::Databases',
70 default => sub { [qw( MySQL SQLite PostgreSQL )] },
79 has schema_version => (
85 # this will probably never get called as the DBICDH
86 # will be passing down a schema_version normally, which
87 # is built the same way, but we leave this in place
88 sub _build_schema_version {
90 $self->schema->schema_version
93 sub __ddl_consume_with_prefix {
94 my ($self, $type, $versions, $prefix) = @_;
95 my $base_dir = $self->script_directory;
97 my $main = catfile( $base_dir, $type );
99 catfile( $base_dir, '_common', $prefix, join q(-), @{$versions} );
102 catfile( $base_dir, '_common', $prefix, '_any' );
106 $dir = catfile($main, $prefix, join q(-), @{$versions})
108 if ($self->ignore_ddl) {
111 croak "$main does not exist; please write/generate some SQL"
114 my $dir_any = catfile($main, $prefix, '_any');
118 opendir my($dh), $dir;
120 map { $_ => "$dir/$_" }
121 grep { /\.(?:sql|pl|sql-\w+)$/ && -f "$dir/$_" }
125 die $_ unless $self->ignore_ddl;
127 for my $dirname (grep { -d $_ } $common, $common_any, $dir_any) {
128 opendir my($dh), $dirname;
129 for my $filename (grep { /\.(?:sql|pl)$/ && -f catfile($dirname,$_) } readdir $dh) {
130 unless ($files{$filename}) {
131 $files{$filename} = catfile($dirname,$filename);
137 return [@files{sort keys %files}]
140 sub _ddl_initialize_consume_filenames {
141 my ($self, $type, $version) = @_;
142 $self->__ddl_consume_with_prefix($type, [ $version ], 'initialize')
145 sub _ddl_schema_consume_filenames {
146 my ($self, $type, $version) = @_;
147 $self->__ddl_consume_with_prefix($type, [ $version ], 'deploy')
150 sub _ddl_protoschema_deploy_consume_filenames {
151 my ($self, $version) = @_;
152 my $base_dir = $self->script_directory;
154 my $dir = catfile( $base_dir, '_source', 'deploy', $version);
155 return [] unless -d $dir;
157 opendir my($dh), $dir;
158 my %files = map { $_ => "$dir/$_" } grep { /\.yml$/ && -f "$dir/$_" } readdir $dh;
161 return [@files{sort keys %files}]
164 sub _ddl_protoschema_upgrade_consume_filenames {
165 my ($self, $versions) = @_;
166 my $base_dir = $self->script_directory;
168 my $dir = catfile( $base_dir, '_preprocess_schema', 'upgrade', join q(-), @{$versions});
170 return [] unless -d $dir;
172 opendir my($dh), $dir;
173 my %files = map { $_ => "$dir/$_" } grep { /\.pl$/ && -f "$dir/$_" } readdir $dh;
176 return [@files{sort keys %files}]
179 sub _ddl_protoschema_downgrade_consume_filenames {
180 my ($self, $versions) = @_;
181 my $base_dir = $self->script_directory;
183 my $dir = catfile( $base_dir, '_preprocess_schema', 'downgrade', join q(-), @{$versions});
185 return [] unless -d $dir;
187 opendir my($dh), $dir;
188 my %files = map { $_ => "$dir/$_" } grep { /\.pl$/ && -f "$dir/$_" } readdir $dh;
191 return [@files{sort keys %files}]
194 sub _ddl_protoschema_produce_filename {
195 my ($self, $version) = @_;
196 my $dirname = catfile( $self->script_directory, '_source', 'deploy', $version );
197 mkpath($dirname) unless -d $dirname;
199 return catfile( $dirname, '001-auto.yml' );
202 sub _ddl_schema_produce_filename {
203 my ($self, $type, $version) = @_;
204 my $dirname = catfile( $self->script_directory, $type, 'deploy', $version );
205 mkpath($dirname) unless -d $dirname;
207 return catfile( $dirname, '001-auto.sql' );
210 sub _ddl_schema_upgrade_consume_filenames {
211 my ($self, $type, $versions) = @_;
212 $self->__ddl_consume_with_prefix($type, $versions, 'upgrade')
215 sub _ddl_schema_downgrade_consume_filenames {
216 my ($self, $type, $versions) = @_;
217 $self->__ddl_consume_with_prefix($type, $versions, 'downgrade')
220 sub _ddl_schema_upgrade_produce_filename {
221 my ($self, $type, $versions) = @_;
222 my $dir = $self->script_directory;
224 my $dirname = catfile( $dir, $type, 'upgrade', join q(-), @{$versions});
225 mkpath($dirname) unless -d $dirname;
227 return catfile( $dirname, '001-auto.sql' );
230 sub _ddl_schema_downgrade_produce_filename {
231 my ($self, $type, $versions, $dir) = @_;
232 my $dirname = catfile( $dir, $type, 'downgrade', join q(-), @{$versions} );
233 mkpath($dirname) unless -d $dirname;
235 return catfile( $dirname, '001-auto.sql');
239 my ($self, $sql) = @_;
240 my $storage = $self->storage;
242 $sql = [ _split_sql_chunk( @$sql ) ];
244 Dlog_trace { "Running SQL $_" } $sql;
245 foreach my $line (@{$sql}) {
246 $storage->_query_start($line);
247 # the whole reason we do this is so that we can see the line that was run
249 $storage->dbh_do (sub { $_[1]->do($line) });
252 die "$_ (running line '$line')"
254 $storage->_query_end($line);
256 return join "\n", @$sql
259 # split a chunk o' SQL into statements
260 sub _split_sql_chunk {
261 my @sql = map { split /;\n/, $_ } @_;
265 s/^(?:BEGIN|BEGIN TRANSACTION|COMMIT).*//mgi;
284 my ($self, $filename) = @_;
285 log_debug { "Running SQL from $filename" };
286 return $self->_run_sql_array($self->_read_sql_file($filename));
292 my $_package = $_file;
293 $_package =~ s/([^A-Za-z0-9_])/sprintf("_%2x", ord($1))/eg;
295 my $fn = eval sprintf <<'END_EVAL', $_package;
296 package DBICDH::Sandbox::%s;
299 $app ||= require $_file;
300 if ( !$app && ( my $error = $@ || $! )) { die $error; }
307 croak "$_file should define an anonymous sub that takes a schema but it didn't!"
308 unless ref $fn && ref $fn eq 'CODE';
314 my ($self, $filename, $versions) = @_;
315 log_debug { "Running Perl from $filename" };
317 my $fn = _load_sandbox($filename);
319 Dlog_trace { "Running Perl $_" } $fn;
321 $fn->($self->schema, $versions)
325 my ( $self, $code ) = @_;
326 return $code->() unless $self->txn_wrap;
328 my $guard = $self->schema->txn_scope_guard;
330 return preserve_context { $code->() } after => sub { $guard->commit };
333 sub _run_sql_and_perl {
334 my ($self, $filenames, $sql_to_run, $versions) = @_;
335 my @files = @{$filenames};
337 $self->_run_sql_array($sql_to_run) if $self->ignore_ddl;
339 my $sql = ($sql_to_run)?join ";\n", @$sql_to_run:'';
341 for my $filename (@files) {
342 if ($self->ignore_ddl && $filename =~ /^[^_]*-auto.*\.sql$/) {
344 } elsif ($filename =~ /\.sql$/) {
345 $sql .= $self->_run_sql($filename)
346 } elsif ( $filename =~ /\.pl$/ ) {
347 $self->_run_perl($filename, $versions)
349 croak "A file ($filename) got to deploy that wasn't sql or perl!";
359 my $version = (shift @_ || {})->{version} || $self->schema_version;
360 log_info { "deploying version $version" };
361 my $sqlt_type = $self->storage->sqlt_type;
363 if ($self->ignore_ddl) {
364 $sql = $self->_sql_from_yaml({},
365 '_ddl_protoschema_deploy_consume_filenames', $sqlt_type
368 return $self->_run_sql_and_perl($self->_ddl_schema_consume_filenames(
371 ), $sql, [$version]);
377 my $version = $args->{version} || $self->schema_version;
378 log_info { "initializing version $version" };
379 my $storage_type = $args->{storage_type} || $self->storage->sqlt_type;
381 my @files = @{$self->_ddl_initialize_consume_filenames(
386 for my $filename (@files) {
387 # We ignore sql for now (till I figure out what to do with it)
388 if ( $filename =~ /^(.+)\.pl$/ ) {
389 my $filedata = do { local( @ARGV, $/ ) = $filename; <> };
391 no warnings 'redefine';
392 my $fn = eval "$filedata";
396 croak "$filename failed to compile: $@";
397 } elsif (ref $fn eq 'CODE') {
400 croak "$filename should define an anonymous sub but it didn't!";
403 croak "A file ($filename) got to initialize_scripts that wasn't sql or perl!";
408 sub _sqldiff_from_yaml {
409 my ($self, $from_version, $to_version, $db, $direction) = @_;
410 my $dir = $self->script_directory;
413 ignore_constraint_names => 1,
414 ignore_index_names => 1,
415 %{$self->sql_translator_args}
420 my $prefilename = $self->_ddl_protoschema_produce_filename($from_version, $dir);
422 # should probably be a croak
423 carp("No previous schema file found ($prefilename)")
424 unless -e $prefilename;
426 my $t = SQL::Translator->new({
430 parser => 'SQL::Translator::Parser::YAML',
433 my $out = $t->translate( $prefilename )
436 $source_schema = $t->schema;
438 $source_schema->name( $prefilename )
439 unless $source_schema->name;
444 my $filename = $self->_ddl_protoschema_produce_filename($to_version, $dir);
446 # should probably be a croak
447 carp("No next schema file found ($filename)")
450 my $t = SQL::Translator->new({
454 parser => 'SQL::Translator::Parser::YAML',
457 my $out = $t->translate( $filename )
460 $dest_schema = $t->schema;
462 $dest_schema->name( $filename )
463 unless $dest_schema->name;
466 my $transform_files_method = "_ddl_protoschema_${direction}_consume_filenames";
467 my $transforms = $self->_coderefs_per_files(
468 $self->$transform_files_method([$from_version, $to_version])
470 $_->($source_schema, $dest_schema) for @$transforms;
472 return [SQL::Translator::Diff::schema_diff(
480 my ($self, $sqltargs, $from_file, $db) = @_;
481 my $schema = $self->schema;
482 my $version = $self->schema_version;
486 my $actual_file = $self->$from_file($version);
487 for my $yaml_filename (@{
488 DlogS_trace { "generating SQL from Serialized SQL Files: $_" }
489 (ref $actual_file?$actual_file:[$actual_file])
491 my $sqlt = SQL::Translator->new({
493 parser => 'SQL::Translator::Parser::YAML',
498 push @sql, $sqlt->translate($yaml_filename);
500 carp("Failed to translate to $db, skipping. (" . $sqlt->error . ")");
507 sub _prepare_install {
509 my $sqltargs = { %{$self->sql_translator_args}, %{shift @_} };
510 my $from_file = shift;
512 my $dir = $self->script_directory;
513 my $databases = $self->databases;
514 my $version = $self->schema_version;
516 foreach my $db (@$databases) {
517 my $sql = $self->_sql_from_yaml($sqltargs, $from_file, $db ) or next;
519 my $filename = $self->$to_file($db, $version, $dir);
521 if ($self->force_overwrite) {
522 carp "Overwriting existing DDL file - $filename";
525 die "Cannot overwrite '$filename', either enable force_overwrite or delete it"
528 open my $file, q(>), $filename;
529 print {$file} join ";\n", @$sql;
534 sub _resultsource_install_filename {
535 my ($self, $source_name) = @_;
537 my ($self, $type, $version) = @_;
538 my $dirname = catfile( $self->script_directory, $type, 'deploy', $version );
539 mkpath($dirname) unless -d $dirname;
541 return catfile( $dirname, "001-auto-$source_name.sql" );
545 sub _resultsource_protoschema_filename {
546 my ($self, $source_name) = @_;
548 my ($self, $version) = @_;
549 my $dirname = catfile( $self->script_directory, '_source', 'deploy', $version );
550 mkpath($dirname) unless -d $dirname;
552 return catfile( $dirname, "001-auto-$source_name.yml" );
556 sub install_resultsource {
557 my ($self, $args) = @_;
558 my $source = $args->{result_source}
559 or die 'result_source must be passed to install_resultsource';
560 my $version = $args->{version}
561 or die 'version must be passed to install_resultsource';
562 log_info { 'installing_resultsource ' . $source->source_name . ", version $version" };
563 my $rs_install_file =
564 $self->_resultsource_install_filename($source->source_name);
567 $self->$rs_install_file(
568 $self->storage->sqlt_type,
572 $self->_run_sql_and_perl($files, '', [$version]);
575 sub prepare_resultsource_install {
577 my $source = (shift @_)->{result_source};
578 log_info { 'preparing install for resultsource ' . $source->source_name };
580 my $install_filename = $self->_resultsource_install_filename($source->source_name);
581 my $proto_filename = $self->_resultsource_protoschema_filename($source->source_name);
582 $self->prepare_protoschema({
583 parser_args => { sources => [$source->source_name], }
585 $self->_prepare_install({}, $proto_filename, $install_filename);
589 log_info { 'preparing deploy' };
591 $self->prepare_protoschema({
592 # Exclude __VERSION so that it gets installed separately
593 parser_args => { sources => [grep { $_ ne '__VERSION' } $self->schema->sources], }
594 }, '_ddl_protoschema_produce_filename');
595 $self->_prepare_install({}, '_ddl_protoschema_produce_filename', '_ddl_schema_produce_filename');
598 sub prepare_upgrade {
599 my ($self, $args) = @_;
601 "preparing upgrade from $args->{from_version} to $args->{to_version}"
603 $self->_prepare_changegrade(
604 $args->{from_version}, $args->{to_version}, $args->{version_set}, 'upgrade'
608 sub prepare_downgrade {
609 my ($self, $args) = @_;
611 "preparing downgrade from $args->{from_version} to $args->{to_version}"
613 $self->_prepare_changegrade(
614 $args->{from_version}, $args->{to_version}, $args->{version_set}, 'downgrade'
618 sub _coderefs_per_files {
619 my ($self, $files) = @_;
620 no warnings 'redefine';
621 [map eval do { local( @ARGV, $/ ) = $_; <> }, @$files]
624 sub _prepare_changegrade {
625 my ($self, $from_version, $to_version, $version_set, $direction) = @_;
626 my $schema = $self->schema;
627 my $databases = $self->databases;
628 my $dir = $self->script_directory;
630 my $schema_version = $self->schema_version;
631 my $diff_file_method = "_ddl_schema_${direction}_produce_filename";
632 foreach my $db (@$databases) {
633 my $diff_file = $self->$diff_file_method($db, $version_set, $dir );
635 if ($self->force_overwrite) {
636 carp("Overwriting existing $direction-diff file - $diff_file");
639 die "Cannot overwrite '$diff_file', either enable force_overwrite or delete it"
643 open my $file, q(>), $diff_file;
644 print {$file} join ";\n", @{$self->_sqldiff_from_yaml($from_version, $to_version, $db, $direction)};
650 my ($self, $file) = @_;
653 local $/ = undef; #sluuuuuurp
655 open my $fh, '<', $file;
656 return [ _split_sql_chunk( <$fh> ) ];
659 sub downgrade_single_step {
661 my $version_set = (shift @_)->{version_set};
662 Dlog_info { "downgrade_single_step'ing $_" } $version_set;
664 my $sqlt_type = $self->storage->sqlt_type;
666 if ($self->ignore_ddl) {
667 $sql_to_run = $self->_sqldiff_from_yaml(
668 $version_set->[0], $version_set->[1], $sqlt_type, 'downgrade',
671 my $sql = $self->_run_sql_and_perl($self->_ddl_schema_downgrade_consume_filenames(
674 ), $sql_to_run, $version_set);
679 sub upgrade_single_step {
681 my $version_set = (shift @_)->{version_set};
682 Dlog_info { "upgrade_single_step'ing $_" } $version_set;
684 my $sqlt_type = $self->storage->sqlt_type;
686 if ($self->ignore_ddl) {
687 $sql_to_run = $self->_sqldiff_from_yaml(
688 $version_set->[0], $version_set->[1], $sqlt_type, 'upgrade',
691 my $sql = $self->_run_sql_and_perl($self->_ddl_schema_upgrade_consume_filenames(
694 ), $sql_to_run, $version_set);
698 sub prepare_protoschema {
700 my $sqltargs = { %{$self->sql_translator_args}, %{shift @_} };
703 = $self->$to_file($self->schema_version);
705 # we do this because the code that uses this sets parser args,
706 # so we just need to merge in the package
707 $sqltargs->{parser_args}{package} = $self->schema;
708 my $sqlt = SQL::Translator->new({
709 parser => 'SQL::Translator::Parser::DBIx::Class',
710 producer => 'SQL::Translator::Producer::YAML',
714 my $yml = $sqlt->translate;
716 croak("Failed to translate to YAML: " . $sqlt->error)
720 if ($self->force_overwrite) {
721 carp "Overwriting existing DDL-YML file - $filename";
724 die "Cannot overwrite '$filename', either enable force_overwrite or delete it"
728 open my $file, q(>), $filename;
733 __PACKAGE__->meta->make_immutable;
737 # vim: ts=2 sw=2 expandtab
743 This class is the meat of L<DBIx::Class::DeploymentHandler>. It takes care
744 of generating serialized schemata as well as sql files to move from one
745 version of a schema to the rest. One of the hallmark features of this class
746 is that it allows for multiple sql files for deploy and upgrade, allowing
747 developers to fine tune deployment. In addition it also allows for perl
748 files to be run at any stage of the process.
750 For basic usage see L<DBIx::Class::DeploymentHandler::HandlesDeploy>. What's
751 documented here is extra fun stuff or private methods.
753 =head1 DIRECTORY LAYOUT
755 Arguably this is the best feature of L<DBIx::Class::DeploymentHandler>.
756 It's spiritually based upon L<DBIx::Migration::Directories>, but has a
757 lot of extensions and modifications, so even if you are familiar with it,
758 please read this. I feel like the best way to describe the layout is with
759 the following example:
785 | | `- 002-remove-customers.pl
788 | | `- 002-generate-customers.pl
790 | `- 999-bump-action.pl
797 | |- 001-create_database.pl
798 | `- 002-create_users_and_permissions.pl
806 So basically, the code
810 on an C<SQLite> database that would simply run
811 C<$sql_migration_dir/SQLite/deploy/1/001-auto.sql>. Next,
813 $dm->upgrade_single_step([1,2])
815 would run C<$sql_migration_dir/SQLite/upgrade/1-2/001-auto.sql> followed by
816 C<$sql_migration_dir/_common/upgrade/1-2/002-generate-customers.pl>, and
817 finally punctuated by
818 C<$sql_migration_dir/_common/upgrade/_any/999-bump-action.pl>.
820 C<.pl> files don't have to be in the C<_common> directory, but most of the time
821 they should be, because perl scripts are generally database independent.
823 Note that unlike most steps in the process, C<initialize> will not run SQL, as
824 there may not even be an database at initialize time. It will run perl scripts
825 just like the other steps in the process, but nothing is passed to them.
826 Until people have used this more it will remain freeform, but a recommended use
827 of initialize is to have it prompt for username and password, and then call the
828 appropriate C<< CREATE DATABASE >> commands etc.
830 =head2 Directory Specification
832 The following subdirectories are recognized by this DeployMethod:
836 =item C<_source> This directory can contain the following directories:
840 =item C<deploy> This directory merely contains directories named after schema
841 versions, which in turn contain C<yaml> files that are serialized versions
842 of the schema at that version. These files are not for editing by hand.
846 =item C<_preprocess_schema> This directory can contain the following
851 =item C<downgrade> This directory merely contains directories named after
852 migrations, which are of the form C<$from_version-$to_version>. Inside of
853 these directories you may put Perl scripts which are to return a subref
854 that takes the arguments C<< $from_schema, $to_schema >>, which are
855 L<SQL::Translator::Schema> objects.
857 =item C<upgrade> This directory merely contains directories named after
858 migrations, which are of the form C<$from_version-$to_version>. Inside of
859 these directories you may put Perl scripts which are to return a subref
860 that takes the arguments C<< $from_schema, $to_schema >>, which are
861 L<SQL::Translator::Schema> objects.
865 =item C<$storage_type> This is a set of scripts that gets run depending on what
866 your storage type is. If you are not sure what your storage type is, take a
867 look at the producers listed for L<SQL::Translator>. Also note, C<_common>
868 is a special case. C<_common> will get merged into whatever other files you
869 already have. This directory can contain the following directories itself:
873 =item C<initialize> Gets run before the C<deploy> is C<deploy>ed. Has the
874 same structure as the C<deploy> subdirectory as well; that is, it has a
875 directory for each schema version. Unlike C<deploy>, C<upgrade>, and C<downgrade>
876 though, it can only run C<.pl> files, and the coderef in the perl files get
877 no arguments passed to them.
879 =item C<deploy> Gets run when the schema is C<deploy>ed. Structure is a
880 directory per schema version, and then files are merged with C<_common> and run
881 in filename order. C<.sql> files are merely run, as expected. C<.pl> files are
882 run according to L</PERL SCRIPTS>.
884 =item C<upgrade> Gets run when the schema is C<upgrade>d. Structure is a directory
885 per upgrade step, (for example, C<1-2> for upgrading from version 1 to version
886 2,) and then files are merged with C<_common> and run in filename order.
887 C<.sql> files are merely run, as expected. C<.pl> files are run according
890 =item C<downgrade> Gets run when the schema is C<downgrade>d. Structure is a directory
891 per downgrade step, (for example, C<2-1> for downgrading from version 2 to version
892 1,) and then files are merged with C<_common> and run in filename order.
893 C<.sql> files are merely run, as expected. C<.pl> files are run according
901 Note that there can be an C<_any> in the place of any of the versions (like
902 C<1-2> or C<1>), which means those scripts will be run B<every> time. So if
903 you have an C<_any> in C<_common/upgrade>, that script will get run for every
908 A perl script for this tool is very simple. It merely needs to contain an
909 anonymous sub that takes a L<DBIx::Class::Schema> and the version set as it's
912 A very basic perl script might look like:
919 use DBIx::Class::DeploymentHandler::DeployMethod::SQL::Translator::ScriptHelpers
920 'schema_from_schema_loader';
922 schema_from_schema_loader({ naming => 'v4' }, sub {
925 # [1] for deploy, [1,2] for upgrade or downgrade, probably used with _any
926 my $versions = shift;
928 $schema->resultset('Users')->create({
934 Note that the above uses
935 L<DBIx::Class::DeploymentHanlder::DeployMethod::SQL::Translator::ScriptHelpers/schema_from_schema_loader>.
936 Using a raw coderef is strongly discouraged as it is likely to break as you
941 This attribute will, when set to true (default is false), cause the DM to use
942 L<SQL::Translator> to use the C<_source>'s serialized SQL::Translator::Schema
943 instead of any pregenerated SQL. If you have a development server this is
944 probably the best plan of action as you will not be putting as many generated
945 files in your version control. Goes well with with C<databases> of C<[]>.
947 =attr force_overwrite
949 When this attribute is true generated files will be overwritten when the
950 methods which create such files are run again. The default is false, in which
951 case the program will die with a message saying which file needs to be deleted.
955 The L<DBIx::Class::Schema> (B<required>) that is used to talk to the database
956 and generate the DDL.
960 The L<DBIx::Class::Storage> that is I<actually> used to talk to the database
961 and generate the DDL. This is automatically created with L</_build_storage>.
963 =attr sql_translator_args
965 The arguments that get passed to L<SQL::Translator> when it's used.
967 =attr script_directory
969 The directory (default C<'sql'>) that scripts are stored in
973 The types of databases (default C<< [qw( MySQL SQLite PostgreSQL )] >>) to
978 Set to true (which is the default) to wrap all upgrades and deploys in a single
983 The version the schema on your harddrive is at. Defaults to
984 C<< $self->schema->schema_version >>.
988 This class is an implementation of
989 L<DBIx::Class::DeploymentHandler::HandlesDeploy>. Pretty much all the
990 documentation is there.