Setting Up a New Docker Swarm on DigitalOcean

As the name suggestions, this is a script for quickly creating a Docker Swarm on DigitalOcean. It enables you to configure the size of the Droplets, the number of managers and workers, and more. Droplets are based on DigitalOcean's One-Click Docker image.

The aim of this script is to be straightforward - a (relatively) simple, mostly automated way to get started setting up a Swarm. If you're looking for a more robust, configurable solution to infrastructure scripting, I recommend taking the time to learn Terraform.

Table of Contents

• Prerequisites
• Getting Started
• Options
• Questions
• Contributing

Prerequisites

While the aim is to keep this simple, there are a few requirements in order to use this script - they're listed here, along with links to the corresponding DigitalOcean guides:

• DigitalOcean account
  Shameless plug here: $100 promo with referral.
• SSH credentials added to your account (DO Guide)
  These provide access to the Droplets and are used by the script to init the Swarm, once the Droplets are created.
• Personal Access Token for the DigialOcean API (DO Guide).
  This is used by DigitalOcean's command-line client to create the Droplets and get information about your account
• Install DigitalOcean's official command-line client, doctl (DO Guide)
  This will do most of the heavily lifting. It's an invaluable tool if you have an account with DigitalOcean, and necessary for this script. Their full doctl tutorial is here.

Getting Started

After completing the prerequisites listed above, here are the steps for using this script:

1. Clone this repository, and navigate into it.

   git clone git@github.com:mjclemente/do-swarm-create.git
   cd do-swarm-create
   

2. Configure the options via environment variables. For example:

    export DO_ENABLE_BACKUPS=false
    export DO_REGION=sfo2
   

3. Run the create-hosts.sh script.

   ./create-hosts.sh
   

4. Confirm Swarm options. Enter yes to proceed or no to cancel.
5. Depending on the options you've set, Swarm creation could take some time. Information about what is being done will be logged in the console as it progresses.

Options

The options for this script are configured via environment variables. Here they are, with their default values:

• DO_DROPLET_NAME
  Default: swarm-node
  Name of the Droplets that are created, followed by incrementing numbers, i.e. swarm-node-2
• DO_SIZE
  Default: s-1vcpu-1gb ($5/mo)
  Size of the Droplets being created. You can get a list of available options by running doctl compute size list
• DO_ENABLE_BACKUPS
  Default: true
  Enables automatic weekly backups of the Droplets. This adds 20% to price. More about backups can be found here.
• DO_ENABLE_UFW
  Default: true
  The UFW firewall is automatically enabled and configured for Docker Swarm use. If you plan on using a DigitalOcean firewall, you'll likely want to set this option to false, so that you don't need to manage two firewalls.
• DO_REGION
  Default: nyc1
  Region in which the Droplet is created. Options can be seen by running doctl compute region list
• DO_TAGS
  Default: $DO_DROPLET_NAME,(master|worker)
  Custom labels for Droplets. Helpful for filtering in when using the DO API, or applying Firewall or Load Balancer rules. By default, the Droplet name variable is applied as a tag to all nodes in the Swarm, but you can override this. The master or worker tags are always included.
• DO_MANAGER_COUNT
  Default: 3
  Number of Swarm managers that should be created.
• DO_WORKER_COUNT
  Default: 0
  Number of Swarm workers that should be created.
• DO_SSH_IDS
  Default: All SSH IDs added to your DO account
  List of SSH keys that should be added to the Droplets, referenced either via their DigitalOcean resource Id, or their fingerprint. If you don't want all the SSH keys in your DO account included, use the command doctl compute ssh-key list to retrieve your SSH keys and selectively add them to this variable.

Questions

For questions that aren't about bugs, feel free to hit me up on Twitter: @mjclemente84. You'll likely get a much faster response than creating an issue here.

Contributing

👍🎉 First off, thanks for taking the time to contribute! 🎉👍

Before putting the work into creating a PR, I'd appreciate it if you opened an issue. That way we can discuss the best way to implement changes/features, before work is done.

Changes should be submitted as Pull Requests on the develop branch.