[hosts] switch to yaml format

hosts.yaml

@@ -0,0 +1,28 @@
+multi:
+  vars:
+    ansible_host: "127.0.0.1"
+    ansible_ssh_user: "vagrant"
+    ansible_ssh_private_key_file: "/home/bronsen/.local/share/vagrant/insecure_private_keys/vagrant.key.rsa"
+    ansible_ssh_host_key_checking: false
+    ansible_ssh_common_args: "-o DSAAuthentication=yes -o IdentitiesOnly=yes -o PubkeyAcceptedKeyTypes=+ssh-rsa -o HostKeyAlgorithms=+ssh-rsa"
+
+    # hide all warnings regarding the discovered python interpreters on the remote side
+    # https://docs.ansible.com/ansible-core/2.18/reference_appendices/interpreter_discovery.html
+    ansible_python_interpreter: "auto_silent"
+
+  children:
+    application_servers:
+    database_servers:
+
+application_servers:
+  hosts:
+    app1:
+      ansible_ssh_port: 2222
+    app2:
+      ansible_ssh_port: 2200
+database_servers:
+  hosts:
+    db:
+      ansible_ssh_port: 2201
+      ansible_become_user: "postgres"
+