Add retries in meta spec and README

Signed-off-by: Leonidas Avdelas <avdelasleonidas@gmail.com>

README.md

@@ -95,6 +95,8 @@ $ git clone https://github.com/borgbase/ansible-role-borgbackup.git roles/ansibl
 - `borg_pip_packages`: Dependancy Packages (pip) to install `borg(backup)` and `borgmatic`.
 - `borg_remote_path`: Path to the borg executable on the remote. It will default to `borg`.
 - `borg_remote_rate_limit`: Remote network upload rate limit in kiBytes/second.
+- `borgmatic_retries`: Number of times to retry a failing backup before giving up. Defaults to 0 (i.e., does not attempt retry).
+- `borgmatic_retry_wait`: Wait time between retries (in seconds) to allow transient issues to pass. Increases after each retry as a form of backoff. Defaults to 0 (no wait).
 - `borg_retention_policy`: Retention policy for how many backups to keep in each category (daily, weekly, monthly, etc).
 - `borg_source_directories`: List of local folders to back up. Default is `/etc/hostname` to prevent an empty backup.
 - `borg_ssh_key_name`: Name of the SSH public and pivate key. Default `id_ed25519`

meta/argument_specs.yml

@@ -102,6 +102,18 @@ argument_specs:
         type: int
         required: false
         description: Remote network upload rate limit in kiBytes/second.
+      borgmatic_retries:
+        type: int
+        required: false
+        description: |
+          Number of times to retry a failing backup before giving up.
+          Defaults to 0 (i.e., does not attempt retry).
+      borgmatic_retry_wait:
+        type: int
+        required: false
+        description: |
+          Wait time between retries (in seconds) to allow transient issues to pass.
+          Increases after each retry as a form of backoff. Defaults to 0 (no wait).
       borg_ssh_key_file_path:
         type: str
         required: false