function emit_document() {
  if (document != "" && !is_secret) {
    printf "%s", document
  }
}

$0 == "---" {
  emit_document()
  document = "---\n"
  is_secret = 0
  next
}

{
  document = document $0 "\n"
  if ($0 ~ /^kind:[[:space:]]*Secret[[:space:]]*$/) {
    is_secret = 1
  }
}

END {
  emit_document()
}