Ghost

Prereqs

• make
• Packer

Build Automation with Packer

Packer is a tool for creating images from a single source configuration. Using this Packer template reduces the entire process of creating, configuring, validating, and snapshotting a build Droplet to a single command:

make build

The Packer build command can also be run manually.

packer build ghost-image.json

Usage

To run the Packer build that this template uses by default, you'll need to install Packer and create a DigitalOcean personal access token and set it to the DIGITALOCEAN_API_TOKEN environment variable. Running packer build ghost-image.json without any other modifications will create a build Droplet configured with Ghost, clean and verify it, then power it down and snapshot it.

⚠️ The image validation script in scripts/999-img_check.sh is copied from the top-level scripts directory in this repository. The top-level location is the script's canonical source, so make sure you're using the latest version from there.

To start adapting this configuration for your own image, you can customize some variables in ghost-image.json:

• do_api_token defines the DO API Token used to create resources via DigitalOcean's API. By default it is set to the value of the DIGITALOCEAN_API_TOKEN environment variable.
• image_name defines the name of the resulting snapshot, which by default is ghost-snapshot- with a UNIX timestamp appended.
• node_version defines the apt repo to use to install Node JS (eg. node_16.x, node_18.x etc)

You can also modify these variables at runtime by using the -var flag.

Configuration Details

By using Packer's DigitalOcean Builder to integrate with the DigitalOcean API, this configuration fully automates Ghost image creation.

This configuration uses Packer's file provisioner to upload complete directories to the Droplet. The contents of files/var/ will be uploaded to /var/. Likewise, the contents of files/etc/ will be uploaded to /etc/. One important thing to note about the file provisioner, from Packer's docs:

The destination directory must already exist. If you need to create it, use a shell provisioner just prior to the file provisioner in order to create the directory. If the destination directory does not exist, the file provisioner may succeed, but it will have undefined results.

This configuration also uses Packer's shell provisioner to run scripts from the /scripts directory and update installed APT packages using an inline task.

After making changes to the configuration, packer validate command.

make validate

Learn more about using Packer in the official Packer documentation.

Copyright & License

Copyright (c) 2013-2023 Andrew Starr-Bochicchio & Ghost Foundation - Released under the MIT license. Ghost and the Ghost Logo are trademarks of Ghost Foundation Ltd. Please see our trademark policy for info on acceptable usage.