auto-join for Beszel agents

beszel.sh

#!/bin/sh
MON_ENDPOINT="https://monitoring.beszel.hub"

case "${1}" in
--help)
  echo "Usage: ${0} <command> <args>"
  echo
  echo "Commands:"
  echo "  login <username> <password>"
  echo "  exists <token> <name> <ip> <port>"
  echo "  join <token> <name> <ip> <port> <user-id>"
  echo "  leave <token> <id>"
  echo "  install <port> <public-key>"
  exit 0
  ;;
login)
  login "${2}" "${3}"
  ;;
exists)
  exists "${2}" "${3}" "${4}" "${5}"
  ;;
join)
  join "${2}" "${3}" "${4}" "${5}" "${6}"
  ;;
leave)
  leave "${2}" "${3}"
  ;;
install)
  install "${2}" "${3}"
  ;;
*)
  echo "Unknown command: ${0} ${1}"
  exit 1
  ;;
esac

# login <username> <password>
login() {
  curl \
    --silent \
    -X POST \
    -H "Content-Type: application/json" \
    --data "{\"identity\":\"${1}\",\"password\":\"${2}\"}" \
    "${MON_ENDPOINT}/api/collections/users/auth-with-password" |
    sed -n 's/.*"token":"\([^"]*\)".*/\1/p'
}

# exists <token> <name> <ip> <port>
exists() {
  response=$(
    curl \
      --silent \
      --get \
      -H "Content-Type: application/json" \
      -H "Authorization: Bearer ${1}" \
      --data-urlencode "filter=name=\"${2}\" && host=\"${3}\" && port=\"${4}\"" \
      "${MON_ENDPOINT}/api/collections/systems/records" |
      sed -n 's/.*"totalItems":\([^,]*\).*/\1/p'
  )

  test "${response}" != "0"
}

# join <token> <name> <ip> <port> <user-id>
join() {
  curl \
    --silent \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer ${1}" \
    --data "{\"name\":\"${2}\",\"host\":\"${3}\",\"port\":${4},\"users\":[\"${5}\"]}" \
    "${MON_ENDPOINT}/api/collections/systems/records" |
    sed -n 's/.*"id":\([^,]*\).*/\1/p'
}

# leave <token> <id>
leave() {
  curl \
    --silent \
    -X DELETE \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer ${1}" \
    "${MON_ENDPOINT}/api/collections/systems/records/${2}"
}

# install <port> <public-key>
install() {
  curl \
    --silent \
    -L https://get.beszel.dev \
    -o /tmp/install-agent.sh

  chmod +x /tmp/install-agent.sh
  /tmp/install-agent.sh -p "${1}" -k "${2}" --auto-update
}