Update your Vultr firewall rules for your ingress SSH

vultr-ssh-updater.sh

#!/usr/bin/env bash
#
# Automatically updates the IP addresses for the ingress rules for SSH access on Vultr
#
# Requires: jq, curl, dig

main() {
  export VULTR_API_KEY="YOUR-VULTR-API-KEY"

  # Get existing rules at the Vultr firewall
  firewall_id=$(get_firewalls)
  rules=$(get_rules_by_firewall_id "$firewall_id")
  firewall_ips=$(echo "$rules" | jq -cr "[.[].subnet] | sort")

  # Get the current external IP addresses
  current_ips=$(get_current_ips)

  # If existing firewall whitelisted IPs are the same as current IPs, do nothing
  test "$firewall_ips" = "$current_ips" && return

  log "Updating firewall rules"
  for id in $(echo "$rules" | jq -cr ".[].id"); do
    log "Deleting firewall rule ID ${id}"
    call DELETE "firewalls/${firewall_id}/rules/${id}"
  done

  log "Creating new rules"
  call POST "firewalls/${firewall_id}/rules" "$(rule_create_payload "$current_ip1")" > /dev/null
  call POST "firewalls/${firewall_id}/rules" "$(rule_create_payload "$current_ip2")" > /dev/null
}

get_current_ips(){
  # Use your custom logic if you have more than one IP address, as long as you return
  # a JSON-encoded string with the IPs in an array.
  echo "[\"${(curl ifconfig.me)\"]" | jq -cr sort
}

rule_create_payload() {
  ip=$1

  echo "{
    \"ip_type\":\"v4\",
    \"protocol\": \"tcp\",
    \"port\": 22,
    \"subnet_size\": 32,
    \"notes\": \"[AUTO] Home network external IP\",
    \"subnet\": \"${ip}\"
  }"
}

log() {
  msg=$1
  date=$(date -u +'%Y-%m-%dT%H:%M:%S.%3NZ')

  echo "[$date] $msg"
}

get_firewalls() {
  call GET firewalls | jq -r '.firewall_groups[] | select(.description == "Home proxy") .id'
}

get_rules_by_firewall_id() {
  local firewall_id=$1
  call GET "firewalls/${firewall_id}/rules" | jq -r '[.firewall_rules[] | select(.notes | contains("[AUTO]"))]'
}

call() {
  local method=$1
  local url=$2
  local params=$3

  curl "https://api.vultr.com/v2/${url}" -X "${method}" \
    -H "Content-Type: application/json" \
    -H "Authorization: Bearer ${VULTR_API_KEY}" \
    --data "$params"
}

main