A workaround is to create a script adding the space needed at the beginning of each line.

```

!/bin/sh

the script read line by line adding two spaces when the line doesn't start with the value:

- vault_: for variables

- -----BEGIN: for certificates

while IFS= read -r line
do
if [[ "$line" == "vault_"* ]] || [[ "$line" == " -----BEGIN"* ]]
then
echo "$line" >> tmp.yml
else
echo " $line" >> tmp.yml
fi
done < "$1"

replace current content with the new YAML file formatted

mv tmp.yml $1
```