ssh_key_path and ssh_user now optional

tasks/main.yml

@@ -8,7 +8,14 @@
     backup_command: |-
       target_path="{{item.target_dir_path}}/$(date -u +'\%Y-\%m-\%dT\%H:\%M:\%SZ').sql"; previous_path="{{item.target_dir_path}}/$(ls --sort=time --format=single-column "{{item.target_dir_path}}" | head --lines 1)";
       {%- if item.source_host is defined %}
-       ssh -i {{item.ssh_key_path}} {{item.ssh_user}}@{{item.source_host}}
+       ssh
+      {%- if item.ssh_key_path is defined %}
+       -o IdentityFile='{{item.ssh_key_path}}'
+      {%- endif %}
+      {%- if item.ssh_user is defined %}
+       -o User={{item.ssh_user}}
+      {%- endif %}
+       {{item.source_host}}
       {%- endif %}
        /usr/bin/mysqldump --opt --order-by-primary --skip-dump-date {{item.database}} | sed 's$),($),\n($g' >"$target_path"; [ "$previous_path" ] && cmp --quiet "$previous_path" "$target_path" && rm "$target_path"
   with_items: '{{mysql_backups}}'