type ssh key

structure.yml

@@ -11,12 +11,18 @@ vps:  # vps target server system variables
 
   ssh_key:
     description: vps ssh private key
+    help: |-
+      - The ssh key path must be accessible (the file must be present)
+      - It is possible not to declare (if the ssh key is your default key)
     examples:
       - ./sshkeys/myssh_privatekey
     type: unix_filename
+    mandatory: false
     params:
       types:
         - file
+      test_existence: true
+      allow_relative: true
 
 nginx:
   description: pedagogic html static file server