Skip to content
Infrastructure and configuration management for creating a NTP Pool server
Ruby Shell
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.

Build Status



This repository can be used to quickly stand up NTP Pool servers. I recently wanted to contribute back to the NTP Pool but do not have have physical resources to donate back with. Using Cloudformation we can provision all of the needed infrastructure and then using Chef we can configure an EC2 instance to the NTP Pool specifications.


The Cloudformation template will create the following resources:

  • VPC
  • 3 subnets, 1 per AZ
  • ACL
    • inbound
      • UDP 123
    • outbound
      • TCP 80
      • TCP 443
      • UDP 123
      • TCP ephemeral ports (1024-65535)
  • Launch Configuration
  • Auto Scaling Group
  • EIP (only if EIP has not be passed into CloudFormation via the eip parameter)

AWS Architecture


I prefer to autogenerate my CloudFormation JSON so I use the cloudformation-ruby-dsl. This section will walk through how to get your environment setup to launch a CloudFormation stack


  • AWS credentials setup. Example using environment variables in ~/.bash_profile:
export AWS_ACCESS_KEY_ID="xxxxxxxx"
export AWS_SECRET_ACCESS_KEY="xxxxxxxx"
  • A sane Ruby environment setup on your workstation. My recommended approach would be to install the ChefDK


# Clone repo from GitHub
git clone
cd ntppool_deployment
bundle install

ntppool_deploument.rb usage message

cd cloudformation
$ bundle exec ntppool_deployment.rb
usage: cloudformation/ntppool_deployment.rb <expand|diff|validate|create|update|cancel-update|delete|describe|describe-resource|get-template>

Launching CloudFormation stack:

bundle exec cloudformation/ntppool_deployment.rb create --region us-west-2 --stack-name ntppool-$(date '+%s') --parameters "environment=production;;eip=;keyName=aboutte;instanceType=t2.micro" --disable-rollback

Validate CloudFormation Syntax:

bundle exec cloudformation/ntppool_deployment.rb validate --region us-west-2 --stack-name ntppool-$(date '+%s') --parameters "environment=production;;eip=;keyName=aboutte;instanceType=t2.micro" --disable-rollback



The following command can be used for testing locally:

cd chef/cookbooks/ntppool_deployment/
export AWS_PROFILE="p"; kitchen verify

Travis CI

Some of the Rake tasks require AWS credentials. I have created a travisci user in my NTP AWS account and provided the following inline IAM Policy:

    "Version": "2012-10-17",
    "Statement": [
            "Sid": "Stmt1489533261000",
            "Effect": "Allow",
            "Action": [
            "Resource": [
            "Sid": "Stmt1489533843000",
            "Effect": "Allow",
            "Action": [
            "Resource": [

Following the Travis CI documentation I encrypted my AWS Key and Secret:

gem install travis
travis encrypt AWS_ACCESS_KEY_ID="AK...EA" --add
travis encrypt AWS_SECRET_ACCESS_KEY="P1V...QDV" --add

which automatically updated my .travis.yml file with the secrets.


  • get Travis CI hooked up
  • updated version of chefdk in kitchen and cloudformation
  • integrate role-base
  • add cloudwatch alarms into deployment
  • remove all the unnecessary rubocop overrides
  • find API to automate the generation of NTP Server
  • write test to validate chef code
You can’t perform that action at this time.