# Context

Project Name: byop-engine (Bring Your Own Platform Engine)

Core Purpose & Vision: byop-engine is a sophisticated "meta-SaaS" platform. Its fundamental goal is to empower other businesses (the "clients" of byop-engine) to effortlessly launch, manage, and scale their own SaaS applications. It aims to abstract away the complexities of infrastructure setup, deployment, and ongoing maintenance, allowing these businesses to concentrate on their core product and customer value. byop-engine automates significant portions of the SaaS operational lifecycle.

Key Features & Value Proposition:

Automated SaaS Deployment Lifecycle:

Application Onboarding: Clients can register their applications with byop-engine, providing details like source code location (e.g., Git repositories), technology stack, and basic configuration needs.
Dockerfile & Docker Compose Generation: A core feature currently under development. byop-engine will intelligently generate Dockerfile and docker-compose.yml files tailored to the client's application, promoting consistency and best practices.
Centralized, Automated Builds: Client application code will be built into Docker images on a dedicated build infrastructure (not on end-user VPS instances). This ensures efficient and reliable builds.
Image Management: Built Docker images will be stored in a self-hosted Docker registry, managed by the byop-engine ecosystem.
VPS Provisioning & Configuration: byop-engine integrates with multiple cloud providers (AWS, DigitalOcean, OVH are currently targeted) to automatically provision new Virtual Private Servers (VPS) for each of its client's end-customers. These VPS instances are intended to be pre-configured with Docker, Docker Compose, and Traefik (as a reverse proxy and for SSL management).
Application Deployment: The system deploys the client's containerized application (using the pre-built image from the self-hosted registry and the generated docker-compose.yml) onto the provisioned VPS. Traefik handles ingress, routing, and SSL termination.
Infrastructure Management & Monitoring:

The system will manage the lifecycle of the provisioned VPS instances.
Future capabilities likely include infrastructure monitoring to ensure the health and availability of client deployments.
Client & Application Management:

Provides a Go-based API (using the Gin framework) for managing byop-engine's clients, their applications, application components, and deployments.
All metadata and state are stored persistently in an SQLite database (byop.db).
Preview & Testing Environment:

An existing previewService allows byop-engine clients to test their application builds in an isolated environment before committing to a full production-style deployment for their end-users.
Support & Operations (Implied):

The codebase includes structures related to "tickets," suggesting a built-in or planned ticketing/support management system, potentially for byop-engine's clients to manage their own end-user support.
High-Level Architecture:

Backend: Written in Go.
API Layer: Exposes a RESTful API (handlers in handlers) using the Gin web framework.
Service Layer (services): Contains the core business logic (e.g., GenerationService, PreviewService, and planned BuildOrchestrationService, DeploymentService).
Data Persistence (dbstore): Uses SQLite (byop.db) for storing all operational data.
Cloud Abstraction (cloud): Provides a common interface to interact with different cloud VPS providers.
Authentication (auth): Manages authentication for byop-engine's clients, likely using JWT.
Configuration (config): Manages application settings.
Dockerized Core: byop-engine itself is designed to be run as a Docker container (as defined by its root Dockerfile).
Current Development Focus (as of June 2025):

The immediate focus is on implementing the GenerationService. This service is responsible for taking application specifications and using Go templates to generate:
Dockerfiles for various stacks (initially Go and Node.js).
docker-compose.yml files that define how client applications will run on the provisioned VPS, including image references (to the self-hosted registry) and Traefik integration for routing and SSL.
Unit tests for the GenerationService are being developed and refined.
The next steps involve creating the BuildOrchestrationService (to manage the build pipeline on a dedicated machine and push to the self-hosted registry) and the DeploymentService (to deploy the generated docker-compose.yml and run the application on the target VPS).
Overall Deployment Strategy for Client Applications:

The chosen strategy emphasizes efficiency and isolation:

Client application code is built into a Docker image on a dedicated build machine.
This image is pushed to a self-hosted Docker registry.
For each end-customer of a byop-engine client, a new, isolated VPS is provisioned.
This VPS runs Traefik for ingress and SSL.
The DeploymentService transfers a generated docker-compose.yml to the VPS. This file references the image in the self-hosted registry.
The application is started on the VPS using docker-compose up -d (after a docker-compose pull).
This "meta-SaaS" approach aims to provide a powerful, automated, yet cost-effective platform for businesses to offer their own SaaS products.

# TODO

Okay, based on our discussion and the goal of implementing the Dockerfile/Compose generation and deployment strategy, here's a potential development plan for byop-engine:

**Phase 1: Core Generation and Build Orchestration**

1.  **Template System Implementation:** ----> DONE
    *   **Action:** Create a new directory, e.g., `templates/`.
    *   **Sub-directories:**
        *   `templates/dockerfile/`: Store `Dockerfile.tmpl` for different stacks (e.g., `nodejs.Dockerfile.tmpl`, `python.Dockerfile.tmpl`, `golang.Dockerfile.tmpl`). Initially, focus on one or two common stacks.
        *   `templates/compose/`: Store `docker-compose.yml.tmpl`. This template will be crucial and needs to include placeholders for:
            *   Service name (e.g., app)
            *   Image name from your self-hosted registry (e.g., `{{ .RegistryURL }}/{{ .AppName }}:{{ .ImageTag }}`)
            *   Ports
            *   Environment variables
            *   Volume mounts (if applicable)
            *   Traefik labels (dynamic based on client's domain, app port, etc.)
    *   **Files:**
        *   `templates/compose/base.docker-compose.yml.tmpl`
        *   `templates/dockerfile/generic.Dockerfile.tmpl` (as a starting point)

2.  **`GenerationService` Implementation:** ----> DONE
    *   **Action:** Create `services/generation_service.go`.
    *   **Responsibilities:**
        *   Define structs to hold data needed for templates (e.g., `DockerfileData`, `ComposeData`).
        *   Functions to parse `.tmpl` files from the `templates/` directory.
        *   Functions to execute templates with provided data and return the generated file content as strings.
        *   Logic to select the correct Dockerfile template based on application type/stack.
    *   **Integration:** This service will be used by other services that need to generate these files.

3.  **`BuildOrchestrationService` Implementation (Conceptual Design & Core Logic):** ----> DONE
    *   **Action:** Create `services/build_orchestration_service.go`.
    *   **Responsibilities (as discussed):**
        *   Define `BuildRequest` and `BuildJob` models (consider adding to models).
        *   Interface for interacting with the dedicated build machine (e.g., via SSH or a small agent on the build machine).
        *   Logic to:
            *   Queue build jobs (initially, an in-memory queue might suffice; consider a persistent queue like Redis/RabbitMQ for future robustness).
            *   Trigger code fetching (Git clone/pull) on the build machine.
            *   Trigger `docker build` on the build machine.
            *   Trigger `docker push` to your self-hosted registry from the build machine.
            *   Update build status in byop.db.
    *   **Database:** Add a `build_jobs` table to byop.db (schema design needed).
    *   **API:** Design internal API/methods for other services to request builds.

4.  **Self-Hosted Registry Integration (Client-Side):**
    *   **Action:** Define how `BuildOrchestrationService` will authenticate and push to your self-hosted registry. This might involve secure configuration management for registry credentials.
    *   **Consideration:** If your registry requires login, the build machine will need credentials.

**Phase 2: Deployment Service & VPS Interaction**

1.  **`DeploymentService` Implementation:**
    *   **Action:** Create `services/deployment_service.go`.
    *   **Responsibilities:**
        *   Define `DeploymentRequest` model.
        *   Interact with provider.go to select/provision a pre-warmed VPS.
        *   Use `GenerationService` to get the `docker-compose.yml` content for the specific deployment (with correct image tag, domain, etc.).
        *   Use ssh_client.go to:
            *   Transfer the generated `docker-compose.yml` to the VPS.
            *   Execute commands on the VPS:
                *   `docker login <your-registry-url>` (if needed, manage credentials securely).
                *   `docker-compose -f <path_to_compose_file> pull`.
                *   `docker-compose -f <path_to_compose_file> up -d`.
        *   Update deployment status and store VPS details (IP, ID) in byop.db.
    *   **Database:** Ensure `deployments` table in byop.db can store necessary info (VPS IP, image tag used, status).

2.  **Traefik Configuration in Templates:**
    *   **Action:** Refine `templates/compose/base.docker-compose.yml.tmpl` to correctly generate Traefik labels.
    *   **Dynamic Data:** The `GenerationService` will need to populate:
        *   `Host()` rule (e.g., `clientname.yourdomain.com` or custom domain).
        *   Service port for Traefik to route to.
        *   Certresolver name.

**Phase 3: API Endpoints & Database Updates**

1.  **API Endpoints for Build and Deployment:**
    *   **Apps Handler (apps.go):**
        *   Endpoint to trigger a new build for an app/version (e.g., `POST /apps/{id}/build`). This would call `BuildOrchestrationService`.
        *   Endpoint to get build status.
    *   **Deployments Handler (deployments.go):**
        *   Endpoint to create a new deployment for an app (e.g., `POST /apps/{id}/deployments`). This would trigger the `DeploymentService`. This might be called internally after a successful build or by an event like a Stripe webhook.
        *   Endpoint to get deployment status.
2.  **Database Schema Updates (dbstore):**
    *   **`apps` table:** Add `current_image_tag` or similar.
    *   **New `build_jobs` table:** `id`, `app_id`, `requested_at`, `started_at`, `finished_at`, `status` (pending, fetching, building, pushing, success, failed), `image_tag`, `error_message`.
    *   **`deployments` table:** Ensure fields for `vps_ip`, `vps_id`, `image_tag_deployed`, `status`, `deployed_at`, `traefik_domain`.
    *   **Action:** Update store.go and relevant model files with new CRUD operations.

**Phase 4: External Systems Setup (Parallel Task)**

1.  **Dedicated Build Machine:**
    *   **Action:** Set up a dedicated machine (VM or physical) with Docker, Git, and any necessary build tools for the languages you'll support.
    *   Secure access for byop-engine to trigger builds (e.g., SSH keys).
2.  **Self-Hosted Docker Registry:**
    *   **Action:** Deploy a Docker registry (e.g., Docker's official `registry:2` image, or more feature-rich ones like Harbor).
    *   Configure security (TLS, authentication).
    *   Ensure the build machine can push to it, and production VPS instances can pull from it.

**Phase 5: Testing and Refinement**

1.  **Unit Tests:** For new services (`GenerationService`, `BuildOrchestrationService`, `DeploymentService`).
2.  **Integration Tests:**
    *   Test template generation.
    *   Test interaction with the (mocked or real) build machine and registry.
    *   Test interaction with (mocked or real) cloud providers and SSH.
3.  **End-to-End Testing:**
    *   Full flow: Define an app -> trigger build -> see image in registry -> trigger deployment -> see app running on a test VPS accessible via Traefik.

This plan is iterative. You can start with a single application stack and a simplified build/deployment flow, then expand capabilities. Remember to handle errors gracefully and provide good feedback to the user/API client at each step.


Improvement: Implement a database migration system.

Introduce Unit and Integration Tests

https://github.com/terser/website
https://github.com/edwardinubuntu/flutter-web-dockerfile
https://github.com/Guy-Incognito/simple-http-server

