add borgmatic role

roles/borgmatic/tasks/handle-ssh-keys.yml

@@ -0,0 +1,25 @@
+---
+- name: "Ensure the path for SSH keys exists"
+  ansible.builtin.file:
+    path: "{{ ssh_key_path | dirname }}"
+    state: directory
+    owner: root
+    group: root
+    mode: "0700"
+
+- name: "Generate an ed25519 SSH key pair with 100 KDF rounds"
+  register: ssh_key_pair
+  community.crypto.openssh_keypair:
+    type: ed25519
+    path: "{{ ssh_key_path }}"
+    comment: "Generated by Ansible for Borgmatic"
+    force: false
+    mode: '0600'
+
+- name: "Push the SSH key pair to the Borg repo host"
+  when: push_pubkey
+  delegate_to: "{{ repo_server_inventory_hostname }}"
+  ansible.posix.authorized_key:
+    user: "{{ repo_server_user }}"
+    key: "{{ ssh_key_pair.public_key }}"
+    state: present