App Store API

Backend API for managing Helm chart installations on a K3s cluster, simulating an app store experience.

Table of Contents

• Prerequisites
• Project Structure
• Configuration
• Getting Started
  • Local Development
• Building
• Docker
• API Endpoints
• Kubernetes Deployment
• Contributing

Prerequisites

• Go (version specified in go.mod, e.g., 1.24)
• Docker
• kubectl
• Helm CLI (v3+)
• A running Kubernetes cluster (e.g., K3s, Minikube, Docker Desktop K8s)
• Access to charts.yaml (local or via ConfigMap)

Project Structure

• cmd/appstore/main.go: Main application entry point.
• pkg/: Contains core packages:
  • api/: HTTP handlers, routes, middleware.
  • appcatalog/: Logic for managing the chart catalog.
  • config/: Application configuration management.
  • helm/: Helm and Kubernetes client interaction logic.
• charts.yaml: Defines the list of available Helm charts for the store.
• Dockerfile: For building the application Docker image.
• k8s/: Kubernetes manifest files for deployment.

Configuration

The application is configured via environment variables. See pkg/config/config.go for details. Key variables:

• APP_PORT: Port the API listens on (default: 8080).
• GIN_MODE: Gin framework mode (debug or release, default: debug).
• APP_INSTALL_NAMESPACE: Kubernetes namespace where charts will be installed (default: app-store-apps).
• KUBECONFIG: Path to the kubeconfig file (tries in-cluster config first, then default path).
• HELM_DRIVER: Helm storage driver (default: secret).
• HELM_TIMEOUT_SECONDS: Timeout for Helm operations (default: 300).
• CHART_CONFIG_PATH: Path to the chart catalog definition file (default: charts.yaml).

The charts.yaml file at the root (or specified by CHART_CONFIG_PATH) defines the applications available in the store.

Getting Started

Local Development

1. Clone the repository:

   git clone https://github.com/YOUR_USERNAME/app-store-api.git
   cd app-store-api

2. Ensure KUBECONFIG is set: Make sure your KUBECONFIG environment variable points to a valid Kubernetes cluster, or that ~/.kube/config is set up. The API needs to interact with a K8s cluster.

3. Install dependencies:

   go mod tidy

4. Run the application:

   go run ./cmd/appstore/main.go

   The API will start, typically on port 8080. Check logs for the exact address and any initialization errors.

   For local development, you might want to set GIN_MODE=debug.

Building

To build the binary:

go build -o app-store-api ./cmd/appstore/main.go

Docker

To build the Docker image:

docker build -t app-store-api:latest .

To run the Docker image (example, assuming KUBECONFIG is mounted and network configured):

docker run -p 8080:8080 \
-v ~/.kube/config:/root/.kube/config:ro \
--env APP_INSTALL_NAMESPACE=my-apps \
app-store-api:latest

Note: For running locally with Docker, ensure the Kubernetes context in the mounted kubeconfig points to a reachable cluster from the Docker container's perspective (e.g., host.docker.internal or an external IP).

API Endpoints

(Refer to pkg/api/routes.go for detailed routes)

• GET /health: Health check.
• GET /api/charts: List available charts.
• POST /api/charts/:chartName/install: Install a chart.
  • Body (JSON, optional): {"release_name": "custom-name", "values": {"key": "value"}}
• GET /api/releases: List installed releases.
• GET /api/releases/:releaseName/status: Get status of a specific release.
• DELETE /api/releases/:releaseName: Uninstall a release.

Kubernetes Deployment

Manifests for deploying the API to Kubernetes are located in the k8s/ directory.

1. Build and push the Docker image to a registry accessible by your K8s cluster (e.g., GHCR, Docker Hub). Example for GHCR: ghcr.io/YOUR_USERNAME/app-store-api:tag
2. Update the image field in k8s/02-deployment.yaml to point to your pushed image.
3. Apply the manifests:

kubectl apply -f k8s/00-namespaces.yaml
kubectl apply -f k8s/01-rbac.yaml
# If using charts.yaml via ConfigMap:
# kubectl create configmap chart-config --from-file=charts.yaml -n app-store-api
kubectl apply -f k8s/02-deployment.yaml
kubectl apply -f k8s/03-service.yaml

Contributing

Please follow Conventional Commits specification for commit messages to enable automated versioning and changelog generation.