$> cat <<EOF > simple_file.sls
/etc/hadoop/placeholder.txt:
   file:
   - managed
   - source: salt://placeholder.txt
   - user: root
   - group: root
   - made: 644

EOF
$> cat <<EOF > placeholder.txt
serial no: 1
EOF
$> salt '*' state.sls simple_file
$> cat /etc/hadoop/placeholder.txt
serial no: 1
$> cat <<EOF > placeholder.txt
serial no: 2
EOF
$> salt '*' state.sls simple_file
$> cat /etc/hadoop/placeholder.txt
serial no: 1
$>