To provide new capabilities, we'll need to grab the puppetlabs-haproxy module and the puppetlabs/app_modeling module from the Forge. If you're using a Puppetfile, simply add them to the Puppetfile. In the following example, I am manually installing these dependencies on an existing master:

[root@pe-puppet-master myapp]# puppet module install puppetlabs-haproxy
Notice: Preparing to install into /etc/puppetlabs/code/environments/production/modules ...
Notice: Downloading from https://forgeapi.puppet.com ...
Notice: Installing -- do not interrupt ...
/etc/puppetlabs/code/environments/production/modules
└─┬ puppetlabs-haproxy (v2.1.0)
  ├── puppetlabs-concat (v4.2.1)
  └── puppetlabs-stdlib (v4.25.1)
[root@pe-puppet-master myapp]# puppet module install puppetlabs/app_modeling
Notice: Preparing to install into /etc/puppetlabs/code/environments/production/modules ...
Notice: Downloading from https://forgeapi.puppet.com ...
Notice: Installing -- do not interrupt ...
/etc/puppetlabs/code/environments/production/modules
└─┬ puppetlabs-app_modeling (v0.2.0)
 └── puppetlabs-stdlib (v4.25.1)

We now have the capability to build haproxy nodes and new app orchestration features via app_modeling.