GitOps automation for SLATE instances

This repository provides a reference implementation of GitOps style automation for SLATE instances. This automation consists of:

-A GitHub Actions workflow for downloading our Python updater script, detecting changes, and running the Python updater

The workflow looks for files that match values.yaml and instance.yaml. When a file associated with an instance is modified the workflow will update that instance. If a file is added, it will be deployed as a new instance.

Setup

Place the Values file values.yaml into a directory that represents the instance for each instance you want to manage. The directory can have any name, and can be nested. The values file must be called exactly values.yaml. Files at the repository root will be ignored. You will also need an instance.yaml for each instance.

Example:

├── <instance-one>
│   ├── instance.yaml
│   ├── values.yaml
├── <instance-two>
│   ├── instance.yaml
│   ├── values.yaml
...
...

Notification Emails

Open ./.github/workflows/slate-deployment.yml and update mailgun_send_to with a comma-delimited list of email addresses for those you wish notified when changes are made.

SLATE Token

You will need to add your SLATE user token (obtained from the SLATE Portal) as a repository secret on your GitHub repository. To do this:

1. Navigate to Settings on the top bar of the GitHub repository interface
2. Choose Secrets --> Actions from the left-hand side bar menu
3. Click the button that says New repository secret upper right
4. Name the secret SLATE_API_TOKEN

Mailgun API Key

You will need to add your Mailgun API Key (optained from the SLATE team) as a repository secret in your GitHub repository. Use the steps described above for SLATE_API_TOKEN to create a new MAILGUN_API_KEY secret.

instance.yaml

For each instance, you must also have a file called instance.yaml that contains some details about the instance. For existing instances, only the instance field is needed to provide the ID. Info about the cluster, group, and app can be used to automatically deploy new instances too.

Optionally you can specify and update the version of the SLATE application with the version field in instance.yaml. If version is unspecified the latest version is the default.

New Instances

To deploy new instances you must include the cluster, group, and app. Version is optional.

cluster: uutah-prod
group: slate-dev
app: nginx
version: 1.2.0

Existing instances

To manage existing instances you only need to specify a SLATE instanceID.

instance: instance_BrX9HtpP1L0

Git force pushes

Force pushes rewrite history in git, and can corrupt the state of your instances. Force pushing should be avoided.

Git pre-commit hooks

This project uses pre-commit to lint all YAML files before allowing git commit to proceed.

Installation

1. Create and activate your preferred Python interpreter (conda, virtualenv, etc.)
2. Install the pre-commit Python package:

   pip install -r requirements.txt

3. Check that pre-commit is properly installed:

   $ pre-commit --version
   pre-commit 2.17.0

4. Install the git hook scripts:

   $ pre-commit install
   pre-commit installed at .git/hooks/pre-commit

Usage

1. Activate the Python interpreter for this project.
2. Develop normally and experience the pre-commit hook during git commit.

Other issues

• If instance deletion is desired, it must currently be performed manually.
• The automation will write back the instance ID for instances that get deployed, this should be refactored to happen on a branch.