Each stack directory has two Ansible playbooks: one that calls Terraform and one that does not.
Each of the subdirectories under stacks/ contains an Ansible playbook called playbook.yml that runs the automation for a full stack build, including calling Terraform as a subtask within the Ansible execution.
As shown in the diagram below, this single Ansible playbook builds the machines and infrastructure for a stack using Terraform, and then runs against the machines to configure SAP. It is not necessary to create an Ansible inventory as it is created dynamically using the outputs received from Terraform.
The initial play of the playbook runs a Terraform module that builds all of the machines to be used for a given stack, and infrastructure such as load balancers if required. The Terraform module always provides an expected output that is used generate an inventory on the fly. After running Terraform and generating this inventory, an Ansible task waits for all of the hosts in the inventory to be accessible over ssh. Subsequent plays of the playbook connect to the machines in the inventory and configure them for SAP.
Running the playbook is done the same for each stack under the stacks/ directory. First create a file containing the variables for the stack, using stacks/<stack>/vars/deploy-vars.yml as a template. Then call ansible-wrapper from the root of the repository.
For example, to build a NetWeaver-HA stack where your variables file is called vars.yml, run:
./ansible-wrapper stacks/NetWeaver-HA/playbook.yml -e @vars.yml
In addition to playbook.yml, each of the subdirectories under stacks/ contains an Ansible playbook called playbook-notf.yml that runs only against machines to configure them for SAP. To use playbook-notf.yml, the infrastructure must already exist and an inventory must be provided. Each stack directory has example inventories provided in both INI and YAML format. Each of the READMEs under stacks also has instructions for defining the inventory needed for that particular stack.
Running playbook-notf.yml is done like playbook.yml, but you also need to supply the inventory file. In the following example, the file is called inventory.yml.
./ansible-wrapper -i inventory.yml stacks/NetWeaver-HA/playbook-notf.yml -e @vars.yml