--output examples --password -l 'foo'
where 'foo' is the name of the variable to set. It will prompt for the password to encrypt. The output will go to stdout, in 2 formats (all one line, multiline). Copy/paste whichever result format you prefer into `/etc/hiera/secrets.eyaml` or into your own `/etc/hiera/environments/<username>_secrets.eyaml`. Double-check your work before saving -- if this file can't be parsed as valid yaml, all puppet runs will fail. A python one line syntax checker is:
python -c "import yaml; f=open('secrets.eyaml','r'); yaml.load(f)" && echo "pass" || echo "FAIL"