NAME

       Rex::Transaction - Transaction support

DESCRIPTION

       With this module you can define transactions and rollback scenarios on failure.

SYNOPSIS

        use Rex::Transaction;

        task 'do-something', 'server01', sub {
          transaction {
            on_rollback {
              rmdir '/tmp/mydata';
            };

            mkdir '/tmp/mydata';
            upload 'files/myapp.tar.gz', '/tmp/mydata';
            run 'tar xzf myapp.tar.gz -C /tmp/mydata';
            if ( $? != 0 ) { die('Error extracting myapp.tar.gz'); }
          };
        };

EXPORTED FUNCTIONS

   transaction($codeRef)
       Start a transaction for $codeRef. If $codeRef dies, Rex will run the on_rollback
       <https://metacpan.org/pod/Rex::Transaction#on_rollback> code to roll back the transaction.

        task 'deploy', group => 'frontend', sub {
          on_rollback {
            rmdir '...';
          };

          deploy 'myapp.tar.gz';
        };

        task 'restart_server', group => 'frontend', sub {
          service apache2 => 'restart';
        };

        task 'all', group => 'frontend', sub {
          transaction {
            do_task [qw/deploy restart_server/];
          };
        };

   on_rollback($codeRef)
       This will execute $codeRef if a step in the transaction
       <https://metacpan.org/pod/Rex::Transaction#transaction> fails.