Gau Backend Services

This repository contains backend services for the "gau" project, organized as a monorepo with multiple Go microservices and supporting scripts.

Structure

• Each service is located in its own directory (e.g., gau-account-service/, gau-cdn-service/, etc.)
• Common scripts for initialization and updates are provided (init.sh, update.sh)
• Each service contains its own source code, configuration, migrations, and deployment scripts (Docker, Kubernetes)

Services

Below is a list of services and their main functionalities. This table will be updated as new services are added.

Service Name	Description / Main Functions	URL
gau-account-service	User account management (authentication, registration, profile, etc.)	https://github.com/tnqbao/gau-account-service
gau-authorization-service	Authorization, access control, and token management	https://github.com/tnqbao/gau-authorization-service.git
gau-cdn-service	CDN and image management	https://github.com/tnqbao/gau-cdn-service
gau-upload-service	File and media upload management	https://github.com/tnqbao/gau-upload-service
gau-kanban-service	Kanban board management (boards, columns, tasks, project management)	https://github.com/tnqbao/gau-kanban-service
gau-email-service	Email sending and notification management	https://github.com/tnqbao/gau-email-service
...	...	(other)

System Architecture

For detailed system architecture diagrams and technical documentation, please refer to ARCHITECT-DOCUMENT.md.

System Overview Diagram

graph TB
    subgraph External["External Layer"]
        Client[Client Applications<br/>Web/Mobile/Desktop]
    end

    subgraph K8s["Kubernetes Cluster"]
        subgraph Ingress["Ingress Layer"]
            Traefik[Traefik<br/>Ingress Controller]
        end

        subgraph Services["Microservices Layer"]
            AccountSvc[Gau Account Service]
            AuthSvc[Gau Authorization Service]
            CDNSvc[Gau CDN Service]
            UploadSvc[Gau Upload Service]
            EmailSvc[Gau Email Service]
        end
    end

    subgraph SharedInfra["Shared Infrastructure"]
        PgPool[(PgPool<br/>PostgreSQL Connection Pooler)]
        CloudflareR2[(Cloudflare R2<br/>Object Storage)]
        Grafana[Grafana OTLP<br/>Observability Platform]
    end

    subgraph DedicatedInfra["Dedicated Infrastructure"]
        subgraph AccountInfra["Account Service Resources"]
            AccountDB[(PostgreSQL<br/>Account Database)]
        end

        subgraph AuthInfra["Authorization Service Resources"]
            AuthDB[(PostgreSQL<br/>Auth Database)]
            AuthRedis[(Redis<br/>Token Store)]
        end

        subgraph CDNInfra["CDN Service Resources"]
            CDNRedis[(Redis<br/>Image Cache)]
        end

        subgraph EmailInfra["Email Service Resources"]
            RabbitMQ[RabbitMQ<br/>Message Queue]
            SMTP[SMTP Server]
        end
    end

    subgraph ExternalAPIs["External APIs"]
        GoogleOAuth[Google OAuth API]
    end

    Client -->|HTTPS| Traefik
    
    Traefik -->|Route: /api/v2/account/*| AccountSvc
    Traefik -->|Route: /images/*| CDNSvc
    
    AccountSvc -->|Internal HTTP| AuthSvc
    AccountSvc -->|Internal HTTP| UploadSvc
    AccountSvc -->|HTTPS| GoogleOAuth
    
    AccountSvc --> PgPool
    PgPool --> AccountDB
    
    AuthSvc --> PgPool
    PgPool --> AuthDB
    AuthSvc --> AuthRedis
    
    CDNSvc --> CloudflareR2
    CDNSvc --> CDNRedis
    
    UploadSvc --> CloudflareR2
    
    RabbitMQ -->|Consume Messages| EmailSvc
    EmailSvc --> SMTP
    
    AccountSvc -.->|Metrics & Logs| Grafana
    AuthSvc -.->|Metrics & Logs| Grafana
    CDNSvc -.->|Metrics & Logs| Grafana
    UploadSvc -.->|Metrics & Logs| Grafana
    EmailSvc -.->|Metrics & Logs| Grafana

    style Traefik fill:#37b24d,stroke:#2b8a3e,color:#fff
    style AccountSvc fill:#4dabf7,stroke:#1c7ed6,color:#fff
    style AuthSvc fill:#4dabf7,stroke:#1c7ed6,color:#fff
    style CDNSvc fill:#4dabf7,stroke:#1c7ed6,color:#fff
    style UploadSvc fill:#4dabf7,stroke:#1c7ed6,color:#fff
    style EmailSvc fill:#4dabf7,stroke:#1c7ed6,color:#fff
    style PgPool fill:#ff6b6b,stroke:#fa5252,color:#fff
    style CloudflareR2 fill:#ff6b6b,stroke:#fa5252,color:#fff
    style Grafana fill:#ff6b6b,stroke:#fa5252,color:#fff

Loading

The system overview diagram illustrates the microservices architecture deployed on Kubernetes Cluster. Client requests flow through the Traefik Ingress Controller, which routes them to appropriate microservices. The system utilizes a combination of shared infrastructure (PgPool, Cloudflare R2, Grafana) and dedicated resources for each service (PostgreSQL databases, Redis instances, RabbitMQ). All services send metrics and logs to Grafana for monitoring and observability.

Architecture Overview

The Gau Backend Microservices system is built on a modern microservices architecture deployed on Kubernetes. The system consists of five core services, each with specific responsibilities, and uses a combination of shared and dedicated infrastructure resources.

Key Components

• Ingress Layer: Traefik Ingress Controller handles all incoming traffic and routes requests to appropriate services
• Microservices Layer: Five independent services (Account, Authorization, CDN, Upload, Email) that can be deployed and scaled independently
• Shared Infrastructure: PgPool (PostgreSQL connection pooler), Cloudflare R2 (object storage), and Grafana OTLP (observability)
• Dedicated Infrastructure: Each service has its own dedicated resources (PostgreSQL databases, Redis instances, RabbitMQ queue)

Service Communication

• Synchronous: HTTP/HTTPS for inter-service communication
• Asynchronous: RabbitMQ message queue for email processing
• Caching: Redis to reduce latency and backend system load

Infrastructure Resources

Service	PostgreSQL	Redis	RabbitMQ	Cloudflare R2	SMTP	External APIs	Grafana OTLP
Gau Account Service	Dedicated via PgPool	N/A	N/A	N/A	N/A	Google OAuth	Shared
Gau Authorization Service	Dedicated via PgPool	Dedicated	N/A	N/A	N/A	N/A	Shared
Gau CDN Service	N/A	Dedicated	N/A	Shared	N/A	N/A	Shared
Gau Upload Service	N/A	N/A	N/A	Shared	N/A	N/A	Shared
Gau Email Service	N/A	N/A	Dedicated Consumer	N/A	Gmail/Custom	N/A	Shared

Service Dependencies

Service	Calls Services	Called By Services
Gau Account Service	Gau Authorization Service, Gau Upload Service	N/A (Entry Point)
Gau Authorization Service	N/A	Gau Account Service, Gau Kanban Service
Gau CDN Service	N/A	N/A (Public Endpoint)
Gau Upload Service	N/A	Gau Account Service
Gau Email Service	N/A	N/A (Consumer Only)

Deployment Information

Kubernetes Configuration

• Orchestration: Kubernetes
• Ingress Controller: Traefik
• Routing Strategy: Path-based routing with annotations
• Deployment Strategy: Rolling update
• Auto Scaling: Horizontal Pod Autoscaler (HPA) configured

Security

• Internal Communication: Private Key validation between services
• External Access: JWT token authentication
• Secret Management: Kubernetes Secrets and ConfigMaps
• TLS/SSL: Handled at Traefik ingress layer

Observability

• Logging: Centralized logging with Grafana OTLP
• Metrics: OpenTelemetry metrics sent to Grafana
• Tracing: Distributed tracing support
• Service Name: Each service has its own service name in Grafana

Scalability

• Stateless Services: All services are stateless and can scale horizontally
• Connection Pooling: PgPool manages PostgreSQL connections efficiently
• Caching Layer: Redis reduces load on database and object storage
• Message Queue: RabbitMQ allows asynchronous task processing
• Object Storage: Cloudflare R2 with Redis cache for serving static content

Design Principles

• Microservices Architecture: Each service has distinct responsibilities
• Service Independence: Services can be deployed and scaled independently
• Data Isolation: Each service manages its own data
• API Gateway Pattern: Traefik serves as the single entry point
• CQRS: Separation of read and write operations in some services

Getting Started

Prerequisites