Gantry

Note: Gantry binaries are not yet published. The project is currently in development.

Gantry is a tool designed to simplify Kubernetes deployments by abstracting away the intricacies and challenges often associated with Kubernetes and Helm charts.

Overview

Helm and Helmfile are amazing tools, and they are required for Gantry to work. However, development teams using these tools often struggle with:

• Steep learning curve for team members not familiar with Kubernetes and Helm
• Enforcing common configuration across charts, e.g. making sure every deployment contains a pod disruption budget
• Creation, maintenance and storage of Helm charts

Example Usage

create a gantry.yaml file for your application, here's an example one for nginx:

name: nginx

image:
  repository: nginx
  tag: latest

ports:
  - name: http
    containerPort: 80 # the port the container listens on
    servicePort: 80 # if specified, creates a corresponding Service resource so that the pod is accessible via the service port

Then run gantry helm install to generate a Helm chart and install it into your cluster. You do not need to publish the Helm chart to a remote repository.

This creates a Helm release named nginx, and then you can use standard Helm commands to interact with the release, such as helm uninstall or helm rollback.

Development

Prerequisites

For local development and testing, we use the following tools:

1. Devbox: A command-line tool that lets you easily create isolated shells for development. It's used to manage project dependencies and provide a consistent development environment.

   To get started with Devbox:

   curl -fsSL https://get.jetpack.io/devbox | bash
   devbox shell
   # optionally install direnv to automatically initialize devbox - https://direnv.net/#basic-installation
   direnv allow
   

2. Just: A handy command runner that serves as a modern alternative to make. It's used to define and run project-specific commands.

   To run a command defined in the Justfile:

   just <command-name>
   

   Commands:

   • build: Compile the project
   • clean: Clean build artifacts
   • up: Start Kind cluster for local testing
   • down: Remove local Kind cluster
   • install-chart: Install Helm chart
   • uninstall-chart: Uninstall Helm chart
   • reinstall-chart: Reinstall Helm chart
   • build-chart: Generate Helm chart to generated-chart directory

3. SBT (Scala Build Tool): The de facto build tool for Scala projects. It's used to compile, test, and run the Scala code.

   To start an SBT session:

   ./sbt
   

4. Docker: Used for containerizing the application and running it locally.

   Make sure you have Docker installed and running on your machine.

TODO

• Basic deployment configuration
• Service and port configuration
• Use HOCON instead of Yaml to configure Gantry
• Publish binaries
• Publish doc site
• Resource and number of replicas configuration
• Liveness/Readiness probes
• Reference/include other configuration files, e.g. to share between applications
• Deployment strategy configuration
• Pod Disruption Budget configuration
• Secret configuration
• Config configuration
• Write tests
• Pre-stop wait to improve networking
• Sidecar support
• Cronjob support
• Option to replace deployment on service major version change
• Configurable entrypoint and command
• Add "Gantry Compose" to deploy multipe services
• GitHub action to install Gantry CLI