Add some documentation for ansible provision mode

Signed-off-by: Anders F Björklund <anders.f.bjorklund@gmail.com>

Author: afbjorklund

examples/default.yaml

@@ -227,6 +227,12 @@ containerd:
 #     #!/bin/bash
 #     dnf config-manager --add-repo ...
 #     dnf install ...
+# # `ansible` is executed after other scripts are complete
+# # It requires `ansible-playbook` command to be installed.
+# # Environment variables such as ANSIBLE_CONFIG can be used, to control the behavior of the playbook execution.
+# # See ansible docs, and `ansible-config`, for more info https://docs.ansible.com/ansible/latest/playbook_guide/
+# - mode: ansible
+#   playbook: playbook.yaml
 
 # Probe scripts to check readiness.
 # 🟢 Builtin default: null

website/content/en/docs/dev/Internals/_index.md

@@ -37,6 +37,9 @@ Metadata:
 cloud-init:
 - `cidata.iso`: cloud-init ISO9660 image. See [`cidata.iso`](#cidataiso).
 
+Ansible:
+- `inventory.yaml`: the Ansible node inventory. See [ansible](#ansible).
+
 disk:
 - `basedisk`: the base image
 - `diffdisk`: the diff image (QCOW2)
@@ -137,6 +140,10 @@ The directory contains the following files:
 - `$QEMU_SYSTEM_ARM`: path of `qemu-system-arm`
   - Default: `qemu-system-arm` in `$PATH`
 
+## Ansible
+The instance directory contains an inventory file, that might be used with Ansible playbooks and commands.
+See [Building Ansible inventories](https://docs.ansible.com/ansible/latest/inventory_guide/) about dynamic inventories.
+
 ## `cidata.iso`
 `cidata.iso` contains the following files: