Invalid Relationship when using require param in class

agent-haproxy.yaml

# /etc/puppetlabs/puppet/node_data/agent-haproxy.yaml
---
agent-haproxy:
  classes:
    linux_postinstall:
      install_packages: tree
      upload_recursive: 'false'
    haproxy:
      require: Class[linux_postinstall]

notes.txt

These run fine without the without the require param.  Also, I am able to run this in a manifest with:

#/etc/puppetlabs/puppet/manifests/site.pp
node default {

  class { "linux_postinstall":
    install_packages => "httpd",
    upload_recursive => "false"
  }
  class { "haproxy" :
    require => Class["linux_postinstall"]
  }
}

puppet-run.out

[root@haproxy ~]# puppet agent -t
Info: Retrieving plugin
Info: Loading facts in /var/lib/puppet/lib/facter/staging_http_get.rb
Info: Loading facts in /var/lib/puppet/lib/facter/ip6tables_version.rb
Info: Loading facts in /var/lib/puppet/lib/facter/default_provider.rb
Info: Loading facts in /var/lib/puppet/lib/facter/os_maj_version.rb
Info: Loading facts in /var/lib/puppet/lib/facter/facter_dot_d.rb
Info: Loading facts in /var/lib/puppet/lib/facter/hyperv_install_status.rb
Info: Loading facts in /var/lib/puppet/lib/facter/rabbitmq_erlang_cookie.rb
Info: Loading facts in /var/lib/puppet/lib/facter/root_home.rb
Info: Loading facts in /var/lib/puppet/lib/facter/puppet_install_dir.rb
Info: Loading facts in /var/lib/puppet/lib/facter/puppet_vardir.rb
Info: Loading facts in /var/lib/puppet/lib/facter/pe_version.rb
Info: Loading facts in /var/lib/puppet/lib/facter/initiator_ports.rb
Info: Loading facts in /var/lib/puppet/lib/facter/iptables_persistent_version.rb
Info: Loading facts in /var/lib/puppet/lib/facter/haproxy_version.rb
Info: Loading facts in /var/lib/puppet/lib/facter/iptables_version.rb
Info: Loading facts in /var/lib/puppet/lib/facter/jboss_home.rb
Info: Loading facts in /var/lib/puppet/lib/facter/concat_basedir.rb
Info: Loading facts in /var/lib/puppet/lib/facter/win_common_desktop_directory.rb
Info: Loading facts in /var/lib/puppet/lib/facter/gemhome.rb
Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Invalid relationship: Class[Haproxy] { require => Class[linux_postinstall] }, because Class[linux_postinstall] doesn't seem to be in the catalog
Warning: Not using cache on failed catalog
Error: Could not retrieve catalog; skipping run

yaml_device.rb

# This is our node_terminus that we are using

require 'puppet/indirector/yaml'
require 'puppet/node'
require 'yaml'

class Puppet::Node::YamlDevice < Puppet::Indirector::Yaml
  desc <<-EOT

    This ENC can be used to specify what resources should be
    configured for a specific node. It can also specify parameters
    and classes like a typical ENC.

    It pulls this classification information from the file:

      $confdir/node_data/<certname>.yaml

    The default location of $confdir is /etc/puppet/ for root
    or ~/.puppet for a system user.

    The data for this file is of the form:

      certname1:
        resources:
          user:
            dan:
              ensure: present
      certname2:
        resources:
          user:
            bob:
              ensure: present


  EOT

  def find(request)
    node_name = request.key
    node = Puppet::Node.new(request.key)
    yaml_file = self.class.device_file(node.name)
    if File.exists?(yaml_file)
      device_hash = YAML.load_file(yaml_file)
      unless device_hash
        raise(Puppet::Error, "Yaml file #{yaml_file} was empty")
      end
      if device_info = device_hash[node_name]
        # TODO for now, I will not allow params or classes to be set here
        # but ,we will probably need it later
        node.parameters = (device_info['parameters'] || {})
        node.classes    = (device_info['classes'] || {})
        if resources = device_info['resources']
          if node.classes
            unless node.classes.class == Hash
              #
              # we have to pass in classes as a Hash b/c we have to set the resource
              # parameter in our class. I will fail if classes were specified as an array
              # b/c otherwise, I have to convert it into a hash which potentially effects
              # things if the user was expecting an array
              #
              raise(Puppet::Error, 'Cannot add resources if an array of classes was passed')
            end
          end
          node.classes.merge!(
            'asm::resource_wrapper' => {'resources' => resources}
          )
        end
      else
        Puppet.warning("Did not find node: #{node_name} in #{yaml_file}")
      end
    else
      Puppet.warning("Yaml file #{yaml_file} does not exist")
    end
    node.fact_merge
    node
  end

  def self.device_file(certname)
    File.expand_path(File.join(Puppet[:confdir], 'node_data', "#{certname}.yaml"))
  end

end

Try changing your yaml this way:

---
agent-haproxy:
  resources:
    class:
      linux_postinstall:
        install_packages: tree
        upload_recursive: 'false'
      haproxy:
        require: Class[linux_postinstall]

Yeah this works for me, it appears when using the standard yaml ENC setting classes doesnt really work too hot, but as we have the asm::resource_wrapper thing i use that here via the resources key to inject this data into a normal manifest where it works fine