quick script to parse vault pki issue responses into tls.pem file

vault-cert-parse.rb

#!/usr/bin/env ruby
#
# Usage:
#
#   vault write pki/issue/role common_name=foo ttl=1h | ruby vault-cert-parse.rb
#
# Creates the file tls.pem containing private-key, cert, and issuing-ca
#
# Can also be used with curl for living on the edge:
#
#   vault write pki/issue/role common_name=foo ttl=1h | curl -sL https://gist.githubusercontent.com/joemiller/dbf79451517c6aefde239431c537b624/raw/vault-cert-parse.rb | ruby

require 'json'

payload = JSON.parse(ARGF.read)

File.open('tls.pem', 'w') do |f|
  f.write(payload['data']['private_key'])
  f.write("\n")
  f.write(payload['data']['certificate'])
  f.write("\n")
  f.write(payload['data']['issuing_ca'])
  f.write("\n")
end