Update Cloudflare with bash

% cat update_cloudflare.sh
#!/bin/bash
# Last modified: 4 May, 2020
# Written by: Me
# This script makes a call to whatismyipaddress and then updates Cloudflare
# with the external IP addresses.

# Cloudflare API is pretty extensive. Documentation is here:
# https://api.cloudflare.com/#dns-records-for-a-zone-update-dns-record

# WhatIsMyIPAddress documentation is here:
# https://whatismyipaddress.com/api
# Note that whatismyipaddress does not want requests more frequent than once
# every 5 minutes.

#Notes
# All requests must include both X-AUTH-KEY and X-AUTH-EMAIL headers.
# Requests that use X-AUTH-USER-SERVICE-KEY can use that instead.

#Global
api_key='redacted'
service_key='redacted'
base_url='https://api.cloudflare.com/client/v4'
email='[email protected]'
my_zoneid='redacted'
my_accountid='redacted'

# These tokens are only viewable once! Don't delete them!
# ... But I'm not sure what they're used for.
token1='redacted'
token2='redacted'

# These functions are working cURL calls that demonstrate usage.
test_tokens () {
  echo "Testing first token, ${token1}"
  curl -X GET "${base_url}/user/tokens/verify" \
       -H "Authorization: Bearer ${token1}" \
       -H "Content-Type:application/json"
  echo ""
  echo "Testing second token, ${token2}"
  curl -X GET "${base_url}/user/tokens/verify" \
       -H "Authorization: Bearer ${token2}" \
       -H "Content-Type:application/json"
}

get_zone_id () {
  curl -X GET "${base_url}/zones" \
       -H "X-Auth-Email: ${email}" \
       -H "X-Auth-Key: ${api_key}" \
       -H "Content-Type: application/json"
}

get_zone_details () {
  curl -X GET "${base_url}/zones/${my_zoneid}" \
       -H "X-Auth-Email: ${email}" \
       -H "X-Auth-Key: ${api_key}" \
       -H "Content-Type: application/json"
}

# This is a useful function since record id's are only available via the API.
get_zone_records () {
  curl -X GET "${base_url}/zones/${my_zoneid}/dns_records" \
       -H "X-Auth-Email: ${email}" \
       -H "X-Auth-Key: ${api_key}" \
       -H "Content-Type: application/json"
}

update_records () {
  # See the output of get_zone_records to find the ids of the individual records.
  local main='redacted'
  local secondary='redacted'
  curl -s -S -X PUT "${base_url}/zones/${my_zoneid}/dns_records/${main}" \
       -H "X-Auth-Email: ${email}" \
       -H "X-Auth-Key: ${api_key}" \
       -H "Content-Type: application/json" \
       --data "{\"type\":\"A\",\"name\":\"mydomain.com\",\"content\":\"${external_ip}\",\"ttl\":1}" > /dev/null
  curl -s -S -X PUT "${base_url}/zones/${my_zoneid}/dns_records/${secondary}" \
       -H "X-Auth-Email: ${email}" \
       -H "X-Auth-Key: ${api_key}" \
       -H "Content-Type: application/json" \
       --data "{\"type\":\"A\",\"name\":\"subdomain.mydomain.com\",\"content\":\"${external_ip}\",\"ttl\":1}" > /dev/null
}

external_ip=`curl -s -S -H "User-Agent: ${my_email}" https://ipv4bot.whatismyipaddress.com`
update_records

exit