Terraforming Minecraft

This is an example of how to write Terraform code and use a Git workflow to manage resources.

In this example we use the Minecraft Terraform provider to give a visual representation of what Terraform does in the background.

Prerequisites

• shipyard
• ngrok
• docker

Demo setup

Route external traffic to GitLab and Minecraft

Start ngrok in order to forward traffic to GitLab. In a new terminal window, run:

make ngrok

Create environment

Create a Minecraft server and GitLab instance and configure them.

make shipyard

Configure Terraform Cloud VCS provider

Now that both GitLab and Minecraft are running, we need to configure Terraform Cloud to use GitLab to drive our Terraform runs. Navigate to Settings > Version control > Providers > Add VCS provider and fill out the forms using the gitlab url that was output by Shipyard as the HTTPS url (even if it is HTTP), and the gitlab url followed by /api/v4 for the API url.

Then following the steps provided by the wizard, log in to GitLab using the credentials for the root user (root / password by default). Then navigate to User Profile > Preferences > Applications and fill out the form using the details provided by Terraform Cloud, and in the final steps fill out the information provided by GitLab into the form in Terraform Cloud. Now that we have the VCS provider set up, we can setup the workspace to use this provider.

Configure Terraform Cloud workspace

Navigate to your workspace and Settings > Version Control, select Gitlab CE as the source and select the repository. Then set the branch to main.

Clone git repository

We are now ready to clone the demo/minecraft git repository and write Terraform code.

eval $(shipyard env)
git clone $gitlab/demo/minecraft.git

Revert commit

An easy way to revert to a previous commit:

git revert --no-commit <commit>..HEAD
git commit -m "Revert back to <commit> because ..."

The safest way to revert to a previous commit, even when there have been merges in between:

git branch backup_main
git reset --hard <commit>
git reset --soft backup_main
git commit -m "Revert back to <commit> because ..."
git branch -d backup_main