Run `apt-get update` before installing other packages with Puppet

I'm trying to create puppet module which automates installation of zend server CE, this is not important here, but steps are as following

1. update /etc/apt/source.list
2. download repos key via wget
3. do apt-get update
4. do apt-get install zend-server-ce-5.2

I have init.pp file

class zendserverce {

# https://github.com/puppetlabs/puppetlabs-stdlib
file_line { 'debian_package':
    path => '/etc/apt/sources.list',
    line => 'deb http://repos.zend.com/zend-server/deb server non-free'
}

exec { "wget http://repos.zend.com/zend.key -O- |apt-key add -":
    path => ["/usr/bin", "/usr/sbin"]
}

exec { "apt-get update":
    command => "/usr/bin/apt-get update",
    onlyif  => "/bin/sh -c '[ ! -f /var/cache/apt/pkgcache.bin ] || /usr/bin/find /etc/apt/* -cnewer /var/cache/apt/pkgcache.bin | /bin/grep . > /dev/null'",
}

package { "zend-server-ce-php-5.2":
    ensure => "latest"
}

}

Seems that puppet runs commands in different order then I need. Is there any way how to for tell him to run in my desired order?

The output of such snippet is

  [0;36mnotice: /Stage[main]/Mc/Package[mc]/ensure: ensure changed 'purged' to 'latest'[0m
  [1;35merr: /Stage[main]/Zendserverce/Package[zend-server-ce-php-5.2]/ensure: change from purged to latest failed: Could not update: Execution of '/usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install zend-server-ce-php-5.2' returned 100: Reading package lists...
  Building dependency tree...
  Reading state information...
  E: Couldn't find package zend-server-ce-php-5.2 at /tmp/vagrant-puppet/modules 0/zendserverce/manifests/init.pp:28[0m
  [0;36mnotice: /Stage[main]/Zendserverce/Exec[wget http://repos.zend.com/zend.key -O- |apt-key add -]/returns: executed successfully[0m
  [0;36mnotice: /Stage[main]/Zendserverce/File_line[debian_package]/ensure: created[0m
  [0;36mnotice: Finished catalog run in 6.75 seconds[0m

So it says: Couldn't find package zend-server-ce-php-5.2

Can anyone guide me what is wrong?

You need to specify the dependency relationships. The easiest/cleanest approach is to use the require parameter which is available for all resource types.

package { "zend-server-ce-php-5.2":
  ensure  => latest,
  require  => Exec['apt-get update'],
}

etc..